143 files changed, 3393 insertions, 2873 deletions

diff --git a/crates/ra_assists/src/assists/add_explicit_type.rs b/crates/ra_assists/src/assists/add_explicit_type.rs
index 562a09685..eeb4ff39f 100644
--- a/crates/ra_assists/src/assists/add_explicit_type.rs
+++ b/crates/ra_assists/src/assists/add_explicit_type.rs
@@ -1,4 +1,4 @@
-use hir::{db::HirDatabase, HirDisplay, Ty};
+use hir::{db::HirDatabase, HirDisplay};
 use ra_syntax::{
     ast::{self, AstNode, LetStmt, NameOwner},
     T,
@@ -43,7 +43,7 @@ pub(crate) fn add_explicit_type(ctx: AssistCtx<impl HirDatabase>) -> Option<Assi
     let analyzer = ctx.source_analyzer(stmt.syntax(), None);
     let ty = analyzer.type_of(db, &expr)?;
     // Assist not applicable if the type is unknown
-    if is_unknown(&ty) {
+    if ty.contains_unknown() {
         return None;
     }
 
@@ -53,15 +53,6 @@ pub(crate) fn add_explicit_type(ctx: AssistCtx<impl HirDatabase>) -> Option<Assi
     })
 }
 
-/// Returns true if any type parameter is unknown
-fn is_unknown(ty: &Ty) -> bool {
-    match ty {
-        Ty::Unknown => true,
-        Ty::Apply(a_ty) => a_ty.parameters.iter().any(is_unknown),
-        _ => false,
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
diff --git a/crates/ra_assists/src/assists/add_new.rs b/crates/ra_assists/src/assists/add_new.rs
index ee8bff346..8f68bd5fb 100644
--- a/crates/ra_assists/src/assists/add_new.rs
+++ b/crates/ra_assists/src/assists/add_new.rs
@@ -35,8 +35,8 @@ pub(crate) fn add_new(ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
     let strukt = ctx.find_node_at_offset::<ast::StructDef>()?;
 
     // We want to only apply this to non-union structs with named fields
-    let field_list = match (strukt.kind(), strukt.is_union()) {
-        (StructKind::Record(named), false) => named,
+    let field_list = match strukt.kind() {
+        StructKind::Record(named) => named,
         _ => return None,
     };
 
diff --git a/crates/ra_assists/src/assists/fill_match_arms.rs b/crates/ra_assists/src/assists/fill_match_arms.rs
index 8482897c5..b75bd44eb 100644
--- a/crates/ra_assists/src/assists/fill_match_arms.rs
+++ b/crates/ra_assists/src/assists/fill_match_arms.rs
@@ -83,10 +83,11 @@ fn resolve_enum_def(
 ) -> Option<ast::EnumDef> {
     let expr_ty = analyzer.type_of(db, &expr)?;
 
-    analyzer.autoderef(db, expr_ty).find_map(|ty| match ty.as_adt() {
-        Some((Adt::Enum(e), _)) => Some(e.source(db).value),
+    let res = expr_ty.autoderef(db).find_map(|ty| match ty.as_adt() {
+        Some(Adt::Enum(e)) => Some(e.source(db).value),
         _ => None,
-    })
+    });
+    res
 }
 
 fn build_pat(var: ast::EnumVariant) -> Option<ast::Pat> {
diff --git a/crates/ra_assists/src/test_db.rs b/crates/ra_assists/src/test_db.rs
index 5f96c974b..523259fd4 100644
--- a/crates/ra_assists/src/test_db.rs
+++ b/crates/ra_assists/src/test_db.rs
@@ -21,6 +21,9 @@ impl salsa::Database for TestDB {
     fn salsa_runtime(&self) -> &salsa::Runtime<Self> {
         &self.runtime
     }
+    fn salsa_runtime_mut(&mut self) -> &mut salsa::Runtime<Self> {
+        &mut self.runtime
+    }
 }
 
 impl std::panic::RefUnwindSafe for TestDB {}
diff --git a/crates/ra_batch/Cargo.toml b/crates/ra_batch/Cargo.toml
index 35626d77d..3bf351fe3 100644
--- a/crates/ra_batch/Cargo.toml
+++ b/crates/ra_batch/Cargo.toml
@@ -15,6 +15,6 @@ crossbeam-channel = "0.4.0"
 ra_vfs = "0.5.0"
 ra_vfs_glob = { path = "../ra_vfs_glob" }
 ra_db = { path = "../ra_db" }
-ra_ide_api = { path = "../ra_ide_api" }
+ra_ide = { path = "../ra_ide" }
 ra_hir = { path = "../ra_hir" }
 ra_project_model = { path = "../ra_project_model" }
diff --git a/crates/ra_batch/src/lib.rs b/crates/ra_batch/src/lib.rs
index cb389eb26..2c9645c00 100644
--- a/crates/ra_batch/src/lib.rs
+++ b/crates/ra_batch/src/lib.rs
@@ -6,7 +6,7 @@ use rustc_hash::FxHashMap;
 
 use crossbeam_channel::{unbounded, Receiver};
 use ra_db::{CrateGraph, FileId, SourceRootId};
-use ra_ide_api::{AnalysisChange, AnalysisHost, FeatureFlags};
+use ra_ide::{AnalysisChange, AnalysisHost, FeatureFlags};
 use ra_project_model::{get_rustc_cfg_options, PackageRoot, ProjectWorkspace};
 use ra_vfs::{RootEntry, Vfs, VfsChange, VfsTask, Watch};
 use ra_vfs_glob::RustPackageFilterBuilder;
diff --git a/crates/ra_cli/Cargo.toml b/crates/ra_cli/Cargo.toml
index c9d3bdb77..c7e0d0f0f 100644
--- a/crates/ra_cli/Cargo.toml
+++ b/crates/ra_cli/Cargo.toml
@@ -8,10 +8,9 @@ publish = false
 [dependencies]
 pico-args = "0.3.0"
 flexi_logger = "0.14.0"
-indicatif = "0.13.0"
 
 ra_syntax = { path = "../ra_syntax" }
-ra_ide_api = { path = "../ra_ide_api" }
+ra_ide = { path = "../ra_ide" }
 ra_batch = { path = "../ra_batch" }
 ra_hir = { path = "../ra_hir" }
 ra_db = { path = "../ra_db" }
diff --git a/crates/ra_cli/src/analysis_bench.rs b/crates/ra_cli/src/analysis_bench.rs
index 8bbe5d9e8..5485a38ff 100644
--- a/crates/ra_cli/src/analysis_bench.rs
+++ b/crates/ra_cli/src/analysis_bench.rs
@@ -10,7 +10,7 @@ use ra_db::{
     salsa::{Database, Durability},
     FileId, SourceDatabaseExt,
 };
-use ra_ide_api::{Analysis, AnalysisChange, AnalysisHost, FilePosition, LineCol};
+use ra_ide::{Analysis, AnalysisChange, AnalysisHost, FilePosition, LineCol};
 
 use crate::Result;
 
@@ -91,7 +91,7 @@ fn do_work<F: Fn(&Analysis) -> T, T>(host: &mut AnalysisHost, file_id: FileId, w
     {
         let start = Instant::now();
         eprint!("trivial change: ");
-        host.raw_database().salsa_runtime().synthetic_write(Durability::LOW);
+        host.raw_database_mut().salsa_runtime_mut().synthetic_write(Durability::LOW);
         work(&host.analysis());
         eprintln!("{:?}", start.elapsed());
     }
@@ -111,7 +111,7 @@ fn do_work<F: Fn(&Analysis) -> T, T>(host: &mut AnalysisHost, file_id: FileId, w
     {
         let start = Instant::now();
         eprint!("const change:   ");
-        host.raw_database().salsa_runtime().synthetic_write(Durability::HIGH);
+        host.raw_database_mut().salsa_runtime_mut().synthetic_write(Durability::HIGH);
         let res = work(&host.analysis());
         eprintln!("{:?}", start.elapsed());
         res
diff --git a/crates/ra_cli/src/analysis_stats.rs b/crates/ra_cli/src/analysis_stats.rs
index c4eb28245..9b1802a5f 100644
--- a/crates/ra_cli/src/analysis_stats.rs
+++ b/crates/ra_cli/src/analysis_stats.rs
@@ -6,7 +6,7 @@ use ra_db::SourceDatabaseExt;
 use ra_hir::{AssocItem, Crate, HasSource, HirDisplay, ModuleDef, Ty, TypeWalk};
 use ra_syntax::AstNode;
 
-use crate::{Result, Verbosity};
+use crate::{progress_report::ProgressReport, Result, Verbosity};
 
 pub fn run(
     verbosity: Verbosity,
@@ -75,17 +75,11 @@ pub fn run(
     println!("Item Collection: {:?}, {}", analysis_time.elapsed(), ra_prof::memory_usage());
 
     let inference_time = Instant::now();
-    let bar = match verbosity {
-        Verbosity::Verbose | Verbosity::Normal => indicatif::ProgressBar::with_draw_target(
-            funcs.len() as u64,
-            indicatif::ProgressDrawTarget::stderr_nohz(),
-        ),
-        Verbosity::Quiet => indicatif::ProgressBar::hidden(),
+    let mut bar = match verbosity {
+        Verbosity::Verbose | Verbosity::Normal => ProgressReport::new(funcs.len() as u64),
+        Verbosity::Quiet => ProgressReport::hidden(),
     };
 
-    bar.set_style(
-        indicatif::ProgressStyle::default_bar().template("{wide_bar} {pos}/{len}\n{msg}"),
-    );
     bar.tick();
     let mut num_exprs = 0;
     let mut num_exprs_unknown = 0;
diff --git a/crates/ra_cli/src/main.rs b/crates/ra_cli/src/main.rs
index a31fd5d6a..fe847e611 100644
--- a/crates/ra_cli/src/main.rs
+++ b/crates/ra_cli/src/main.rs
@@ -3,12 +3,13 @@
 mod analysis_stats;
 mod analysis_bench;
 mod help;
+mod progress_report;
 
 use std::{error::Error, fmt::Write, io::Read};
 
 use flexi_logger::Logger;
 use pico_args::Arguments;
-use ra_ide_api::{file_structure, Analysis};
+use ra_ide::{file_structure, Analysis};
 use ra_prof::profile;
 use ra_syntax::{AstNode, SourceFile};
 
diff --git a/crates/ra_cli/src/progress_report.rs b/crates/ra_cli/src/progress_report.rs
new file mode 100644
index 000000000..31867a1e9
--- /dev/null
+++ b/crates/ra_cli/src/progress_report.rs
@@ -0,0 +1,120 @@
+//! A simple progress bar
+//!
+//! A single thread non-optimized progress bar
+use std::io::Write;
+
+/// A Simple ASCII Progress Bar
+pub struct ProgressReport {
+    curr: f32,
+    text: String,
+    hidden: bool,
+
+    len: u64,
+    pos: u64,
+    msg: String,
+}
+
+impl ProgressReport {
+    pub fn new(len: u64) -> ProgressReport {
+        ProgressReport {
+            curr: 0.0,
+            text: String::new(),
+            hidden: false,
+            len,
+            pos: 0,
+            msg: String::new(),
+        }
+    }
+
+    pub fn hidden() -> ProgressReport {
+        ProgressReport {
+            curr: 0.0,
+            text: String::new(),
+            hidden: true,
+            len: 0,
+            pos: 0,
+            msg: String::new(),
+        }
+    }
+
+    pub fn set_message(&mut self, msg: &str) {
+        self.msg = msg.to_string();
+        self.tick();
+    }
+
+    pub fn println<I: Into<String>>(&mut self, msg: I) {
+        self.clear();
+        println!("{}", msg.into());
+        self.tick();
+    }
+
+    pub fn inc(&mut self, delta: u64) {
+        self.pos += delta;
+        if self.len == 0 {
+            self.set_value(0.0)
+        } else {
+            self.set_value((self.pos as f32) / (self.len as f32))
+        }
+        self.tick();
+    }
+
+    pub fn finish_and_clear(&mut self) {
+        self.clear();
+    }
+
+    pub fn tick(&mut self) {
+        if self.hidden {
+            return;
+        }
+        let percent = (self.curr * 100.0) as u32;
+        let text = format!("{}/{} {:3>}% {}", self.pos, self.len, percent, self.msg);
+        self.update_text(&text);
+    }
+
+    fn update_text(&mut self, text: &str) {
+        // Get length of common portion
+        let mut common_prefix_length = 0;
+        let common_length = usize::min(self.text.len(), text.len());
+
+        while common_prefix_length < common_length
+            && text.chars().nth(common_prefix_length).unwrap()
+                == self.text.chars().nth(common_prefix_length).unwrap()
+        {
+            common_prefix_length += 1;
+        }
+
+        // Backtrack to the first differing character
+        let mut output = String::new();
+        output += &'\x08'.to_string().repeat(self.text.len() - common_prefix_length);
+        // Output new suffix
+        output += &text[common_prefix_length..text.len()];
+
+        // If the new text is shorter than the old one: delete overlapping characters
+        if let Some(overlap_count) = self.text.len().checked_sub(text.len()) {
+            if overlap_count > 0 {
+                output += &" ".repeat(overlap_count);
+                output += &"\x08".repeat(overlap_count);
+            }
+        }
+
+        let _ = std::io::stdout().write(output.as_bytes());
+        let _ = std::io::stdout().flush();
+        self.text = text.to_string();
+    }
+
+    fn set_value(&mut self, value: f32) {
+        self.curr = f32::max(0.0, f32::min(1.0, value));
+    }
+
+    fn clear(&mut self) {
+        if self.hidden {
+            return;
+        }
+
+        // Fill all last text to space and return the cursor
+        let spaces = " ".repeat(self.text.len());
+        let backspaces = "\x08".repeat(self.text.len());
+        print!("{}{}{}", backspaces, spaces, backspaces);
+        self.text = String::new();
+    }
+}
diff --git a/crates/ra_db/Cargo.toml b/crates/ra_db/Cargo.toml
index 4ec09b6d9..7afa5d8fc 100644
--- a/crates/ra_db/Cargo.toml
+++ b/crates/ra_db/Cargo.toml
@@ -8,7 +8,7 @@ authors = ["rust-analyzer developers"]
 doctest = false
 
 [dependencies]
-salsa = "0.13.0"
+salsa = "0.14.1"
 relative-path = "1.0.0"
 rustc-hash = "1.0"
 
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index e8852531b..21341b769 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -1,4 +1,4 @@
-//! ra_db defines basic database traits. The concrete DB is defined by ra_ide_api.
+//! ra_db defines basic database traits. The concrete DB is defined by ra_ide.
 mod cancellation;
 mod input;
 pub mod fixture;
diff --git a/crates/ra_hir/Cargo.toml b/crates/ra_hir/Cargo.toml
index 42ddfecc9..e79361e7c 100644
--- a/crates/ra_hir/Cargo.toml
+++ b/crates/ra_hir/Cargo.toml
@@ -8,28 +8,11 @@ authors = ["rust-analyzer developers"]
 doctest = false
 
 [dependencies]
-arrayvec = "0.5.1"
 log = "0.4.5"
 rustc-hash = "1.0"
-parking_lot = "0.9.0"
-ena = "0.13"
-once_cell = "1.0.1"
 
 ra_syntax = { path = "../ra_syntax" }
-ra_arena = { path = "../ra_arena" }
-ra_cfg = { path = "../ra_cfg" }
 ra_db = { path = "../ra_db" }
-mbe = { path = "../ra_mbe", package = "ra_mbe" }
-tt = { path = "../ra_tt", package = "ra_tt" }
 hir_expand = { path = "../ra_hir_expand", package = "ra_hir_expand" }
 hir_def = { path = "../ra_hir_def", package = "ra_hir_def" }
-test_utils = { path = "../test_utils" }
-ra_prof = { path = "../ra_prof" }
-
-chalk-solve = { git = "https://github.com/rust-lang/chalk.git", rev = "a88cad7f0a69e05ba8f40b74c58a1c229c1b2478" }
-chalk-rust-ir = { git = "https://github.com/rust-lang/chalk.git", rev = "a88cad7f0a69e05ba8f40b74c58a1c229c1b2478" }
-chalk-ir = { git = "https://github.com/rust-lang/chalk.git", rev = "a88cad7f0a69e05ba8f40b74c58a1c229c1b2478" }
-lalrpop-intern = "0.15.1"
-
-[dev-dependencies]
-insta = "0.12.0"
+hir_ty = { path = "../ra_hir_ty", package = "ra_hir_ty" }
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 3f44a50c4..38d66c2a7 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -6,28 +6,31 @@ use std::sync::Arc;
 
 use hir_def::{
     adt::VariantData,
+    body::{Body, BodySourceMap},
     builtin_type::BuiltinType,
     docs::Documentation,
+    expr::{BindingAnnotation, Pat, PatId},
     per_ns::PerNs,
-    resolver::{HasResolver, TypeNs},
-    type_ref::TypeRef,
-    AstItemDef, ConstId, ContainerId, EnumId, FunctionId, HasModule, ImplId, LocalEnumVariantId,
-    LocalImportId, LocalModuleId, LocalStructFieldId, Lookup, ModuleId, StaticId, StructId,
-    TraitId, TypeAliasId, UnionId,
+    resolver::HasResolver,
+    type_ref::{Mutability, TypeRef},
+    AdtId, AstItemDef, ConstId, ContainerId, DefWithBodyId, EnumId, FunctionId, GenericDefId,
+    HasModule, ImplId, LocalEnumVariantId, LocalImportId, LocalModuleId, LocalStructFieldId,
+    Lookup, ModuleId, StaticId, StructId, TraitId, TypeAliasId, UnionId,
 };
 use hir_expand::{
     diagnostics::DiagnosticSink,
     name::{self, AsName},
     AstId, MacroDefId,
 };
+use hir_ty::expr::ExprValidator;
 use ra_db::{CrateId, Edition, FileId, FilePosition};
 use ra_syntax::{ast, AstNode, SyntaxNode};
 
 use crate::{
     db::{DefDatabase, HirDatabase},
-    expr::{BindingAnnotation, Body, BodySourceMap, ExprValidator, Pat, PatId},
-    ty::{InferenceResult, Namespace, TraitRef},
-    Either, Name, Source, Ty,
+    ty::display::HirFormatter,
+    ty::{self, InEnvironment, InferenceResult, TraitEnvironment, Ty, TyDefId, TypeCtor, TypeWalk},
+    CallableDef, Either, HirDisplay, Name, Source,
 };
 
 /// hir::Crate describes a single crate. It's the main interface with which
@@ -168,15 +171,15 @@ pub use hir_def::attr::Attrs;
 
 impl Module {
     pub(crate) fn new(krate: Crate, crate_module_id: LocalModuleId) -> Module {
-        Module { id: ModuleId { krate: krate.crate_id, module_id: crate_module_id } }
+        Module { id: ModuleId { krate: krate.crate_id, local_id: crate_module_id } }
     }
 
     /// Name of this module.
     pub fn name(self, db: &impl DefDatabase) -> Option<Name> {
         let def_map = db.crate_def_map(self.id.krate);
-        let parent = def_map[self.id.module_id].parent?;
+        let parent = def_map[self.id.local_id].parent?;
         def_map[parent].children.iter().find_map(|(name, module_id)| {
-            if *module_id == self.id.module_id {
+            if *module_id == self.id.local_id {
                 Some(name.clone())
             } else {
                 None
@@ -200,14 +203,14 @@ impl Module {
     /// Finds a child module with the specified name.
     pub fn child(self, db: &impl DefDatabase, name: &Name) -> Option<Module> {
         let def_map = db.crate_def_map(self.id.krate);
-        let child_id = def_map[self.id.module_id].children.get(name)?;
+        let child_id = def_map[self.id.local_id].children.get(name)?;
         Some(self.with_module_id(*child_id))
     }
 
     /// Iterates over all child modules.
     pub fn children(self, db: &impl DefDatabase) -> impl Iterator<Item = Module> {
         let def_map = db.crate_def_map(self.id.krate);
-        let children = def_map[self.id.module_id]
+        let children = def_map[self.id.local_id]
             .children
             .iter()
             .map(|(_, module_id)| self.with_module_id(*module_id))
@@ -218,7 +221,7 @@ impl Module {
     /// Finds a parent module.
     pub fn parent(self, db: &impl DefDatabase) -> Option<Module> {
         let def_map = db.crate_def_map(self.id.krate);
-        let parent_id = def_map[self.id.module_id].parent?;
+        let parent_id = def_map[self.id.local_id].parent?;
         Some(self.with_module_id(parent_id))
     }
 
@@ -234,7 +237,7 @@ impl Module {
 
     /// Returns a `ModuleScope`: a set of items, visible in this module.
     pub fn scope(self, db: &impl HirDatabase) -> Vec<(Name, ScopeDef, Option<Import>)> {
-        db.crate_def_map(self.id.krate)[self.id.module_id]
+        db.crate_def_map(self.id.krate)[self.id.local_id]
             .scope
             .entries()
             .map(|(name, res)| {
@@ -244,7 +247,7 @@ impl Module {
     }
 
     pub fn diagnostics(self, db: &impl HirDatabase, sink: &mut DiagnosticSink) {
-        db.crate_def_map(self.id.krate).add_diagnostics(db, self.id.module_id, sink);
+        db.crate_def_map(self.id.krate).add_diagnostics(db, self.id.local_id, sink);
         for decl in self.declarations(db) {
             match decl {
                 crate::ModuleDef::Function(f) => f.diagnostics(db, sink),
@@ -269,12 +272,12 @@ impl Module {
 
     pub fn declarations(self, db: &impl DefDatabase) -> Vec<ModuleDef> {
         let def_map = db.crate_def_map(self.id.krate);
-        def_map[self.id.module_id].scope.declarations().map(ModuleDef::from).collect()
+        def_map[self.id.local_id].scope.declarations().map(ModuleDef::from).collect()
     }
 
     pub fn impl_blocks(self, db: &impl DefDatabase) -> Vec<ImplBlock> {
         let def_map = db.crate_def_map(self.id.krate);
-        def_map[self.id.module_id].impls.iter().copied().map(ImplBlock::from).collect()
+        def_map[self.id.local_id].impls.iter().copied().map(ImplBlock::from).collect()
     }
 
     fn with_module_id(self, module_id: LocalModuleId) -> Module {
@@ -320,14 +323,14 @@ pub struct Struct {
 
 impl Struct {
     pub fn module(self, db: &impl DefDatabase) -> Module {
-        Module { id: self.id.0.module(db) }
+        Module { id: self.id.module(db) }
     }
 
     pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
         Some(self.module(db).krate())
     }
 
-    pub fn name(self, db: &impl DefDatabase) -> Option<Name> {
+    pub fn name(self, db: &impl DefDatabase) -> Name {
         db.struct_data(self.id.into()).name.clone()
     }
 
@@ -349,12 +352,12 @@ impl Struct {
             .map(|(id, _)| StructField { parent: self.into(), id })
     }
 
-    pub fn ty(self, db: &impl HirDatabase) -> Ty {
-        db.type_for_def(self.into(), Namespace::Types)
+    pub fn ty(self, db: &impl HirDatabase) -> Type {
+        Type::from_def(db, self.id.module(db).krate, self.id)
     }
 
     pub fn constructor_ty(self, db: &impl HirDatabase) -> Ty {
-        db.type_for_def(self.into(), Namespace::Values)
+        db.value_ty(self.id.into())
     }
 
     fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
@@ -368,16 +371,38 @@ pub struct Union {
 }
 
 impl Union {
-    pub fn name(self, db: &impl DefDatabase) -> Option<Name> {
-        db.struct_data(self.id.into()).name.clone()
+    pub fn name(self, db: &impl DefDatabase) -> Name {
+        db.union_data(self.id).name.clone()
     }
 
     pub fn module(self, db: &impl DefDatabase) -> Module {
-        Module { id: self.id.0.module(db) }
+        Module { id: self.id.module(db) }
     }
 
-    pub fn ty(self, db: &impl HirDatabase) -> Ty {
-        db.type_for_def(self.into(), Namespace::Types)
+    pub fn ty(self, db: &impl HirDatabase) -> Type {
+        Type::from_def(db, self.id.module(db).krate, self.id)
+    }
+
+    pub fn fields(self, db: &impl HirDatabase) -> Vec<StructField> {
+        db.union_data(self.id)
+            .variant_data
+            .fields()
+            .iter()
+            .map(|(id, _)| StructField { parent: self.into(), id })
+            .collect()
+    }
+
+    pub fn field(self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
+        db.union_data(self.id)
+            .variant_data
+            .fields()
+            .iter()
+            .find(|(_id, data)| data.name == *name)
+            .map(|(id, _)| StructField { parent: self.into(), id })
+    }
+
+    fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
+        db.union_data(self.id).variant_data.clone()
     }
 }
 
@@ -395,7 +420,7 @@ impl Enum {
         Some(self.module(db).krate())
     }
 
-    pub fn name(self, db: &impl DefDatabase) -> Option<Name> {
+    pub fn name(self, db: &impl DefDatabase) -> Name {
         db.enum_data(self.id).name.clone()
     }
 
@@ -408,15 +433,12 @@ impl Enum {
     }
 
     pub fn variant(self, db: &impl DefDatabase, name: &Name) -> Option<EnumVariant> {
-        db.enum_data(self.id)
-            .variants
-            .iter()
-            .find(|(_id, data)| data.name.as_ref() == Some(name))
-            .map(|(id, _)| EnumVariant { parent: self, id })
+        let id = db.enum_data(self.id).variant(name)?;
+        Some(EnumVariant { parent: self, id })
     }
 
-    pub fn ty(self, db: &impl HirDatabase) -> Ty {
-        db.type_for_def(self.into(), Namespace::Types)
+    pub fn ty(self, db: &impl HirDatabase) -> Type {
+        Type::from_def(db, self.id.module(db).krate, self.id)
     }
 }
 
@@ -434,7 +456,7 @@ impl EnumVariant {
         self.parent
     }
 
-    pub fn name(self, db: &impl DefDatabase) -> Option<Name> {
+    pub fn name(self, db: &impl DefDatabase) -> Name {
         db.enum_data(self.parent.id).variants[self.id].name.clone()
     }
 
@@ -469,12 +491,13 @@ pub enum Adt {
 impl_froms!(Adt: Struct, Union, Enum);
 
 impl Adt {
-    pub fn ty(self, db: &impl HirDatabase) -> Ty {
-        match self {
-            Adt::Struct(it) => it.ty(db),
-            Adt::Union(it) => it.ty(db),
-            Adt::Enum(it) => it.ty(db),
-        }
+    pub fn has_non_default_type_params(self, db: &impl HirDatabase) -> bool {
+        let subst = db.generic_defaults(self.into());
+        subst.iter().any(|ty| ty == &Ty::Unknown)
+    }
+    pub fn ty(self, db: &impl HirDatabase) -> Type {
+        let id = AdtId::from(self);
+        Type::from_def(db, id.module(db).krate, id)
     }
 
     pub fn module(self, db: &impl DefDatabase) -> Module {
@@ -493,28 +516,24 @@ impl Adt {
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub enum VariantDef {
     Struct(Struct),
+    Union(Union),
     EnumVariant(EnumVariant),
 }
-impl_froms!(VariantDef: Struct, EnumVariant);
+impl_froms!(VariantDef: Struct, Union, EnumVariant);
 
 impl VariantDef {
     pub fn fields(self, db: &impl HirDatabase) -> Vec<StructField> {
         match self {
             VariantDef::Struct(it) => it.fields(db),
+            VariantDef::Union(it) => it.fields(db),
             VariantDef::EnumVariant(it) => it.fields(db),
         }
     }
 
-    pub(crate) fn field(self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
-        match self {
-            VariantDef::Struct(it) => it.field(db, name),
-            VariantDef::EnumVariant(it) => it.field(db, name),
-        }
-    }
-
     pub fn module(self, db: &impl HirDatabase) -> Module {
         match self {
             VariantDef::Struct(it) => it.module(db),
+            VariantDef::Union(it) => it.module(db),
             VariantDef::EnumVariant(it) => it.module(db),
         }
     }
@@ -522,6 +541,7 @@ impl VariantDef {
     pub(crate) fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
         match self {
             VariantDef::Struct(it) => it.variant_data(db),
+            VariantDef::Union(it) => it.variant_data(db),
             VariantDef::EnumVariant(it) => it.variant_data(db),
         }
     }
@@ -538,14 +558,6 @@ pub enum DefWithBody {
 impl_froms!(DefWithBody: Function, Const, Static);
 
 impl DefWithBody {
-    pub(crate) fn krate(self, db: &impl HirDatabase) -> Option<Crate> {
-        match self {
-            DefWithBody::Const(c) => c.krate(db),
-            DefWithBody::Function(f) => f.krate(db),
-            DefWithBody::Static(s) => s.krate(db),
-        }
-    }
-
     pub fn module(self, db: &impl HirDatabase) -> Module {
         match self {
             DefWithBody::Const(c) => c.module(db),
@@ -590,11 +602,11 @@ impl Function {
     }
 
     pub fn ty(self, db: &impl HirDatabase) -> Ty {
-        db.type_for_def(self.into(), Namespace::Values)
+        db.value_ty(self.id.into())
     }
 
     pub fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
-        db.infer(self.into())
+        db.infer(self.id.into())
     }
 
     /// The containing impl block, if this is a method.
@@ -623,8 +635,8 @@ impl Function {
 
     pub fn diagnostics(self, db: &impl HirDatabase, sink: &mut DiagnosticSink) {
         let infer = self.infer(db);
-        infer.add_diagnostics(db, self, sink);
-        let mut validator = ExprValidator::new(self, infer, sink);
+        infer.add_diagnostics(db, self.id, sink);
+        let mut validator = ExprValidator::new(self.id, infer, sink);
         validator.validate_body(db);
     }
 }
@@ -648,7 +660,7 @@ impl Const {
     }
 
     pub fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
-        db.infer(self.into())
+        db.infer(self.id.into())
     }
 
     /// The containing impl block, if this is a type alias.
@@ -691,7 +703,7 @@ impl Static {
     }
 
     pub fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
-        db.infer(self.into())
+        db.infer(self.id.into())
     }
 }
 
@@ -705,73 +717,12 @@ impl Trait {
         Module { id: self.id.module(db) }
     }
 
-    pub fn name(self, db: &impl DefDatabase) -> Option<Name> {
+    pub fn name(self, db: &impl DefDatabase) -> Name {
         db.trait_data(self.id).name.clone()
     }
 
     pub fn items(self, db: &impl DefDatabase) -> Vec<AssocItem> {
-        db.trait_data(self.id).items.iter().map(|it| (*it).into()).collect()
-    }
-
-    fn direct_super_traits(self, db: &impl HirDatabase) -> Vec<Trait> {
-        let resolver = self.id.resolver(db);
-        // returning the iterator directly doesn't easily work because of
-        // lifetime problems, but since there usually shouldn't be more than a
-        // few direct traits this should be fine (we could even use some kind of
-        // SmallVec if performance is a concern)
-        db.generic_params(self.id.into())
-            .where_predicates
-            .iter()
-            .filter_map(|pred| match &pred.type_ref {
-                TypeRef::Path(p) if p.as_ident() == Some(&name::SELF_TYPE) => pred.bound.as_path(),
-                _ => None,
-            })
-            .filter_map(|path| match resolver.resolve_path_in_type_ns_fully(db, path) {
-                Some(TypeNs::TraitId(t)) => Some(t),
-                _ => None,
-            })
-            .map(Trait::from)
-            .collect()
-    }
-
-    /// Returns an iterator over the whole super trait hierarchy (including the
-    /// trait itself).
-    pub fn all_super_traits(self, db: &impl HirDatabase) -> Vec<Trait> {
-        // we need to take care a bit here to avoid infinite loops in case of cycles
-        // (i.e. if we have `trait A: B; trait B: A;`)
-        let mut result = vec![self];
-        let mut i = 0;
-        while i < result.len() {
-            let t = result[i];
-            // yeah this is quadratic, but trait hierarchies should be flat
-            // enough that this doesn't matter
-            for tt in t.direct_super_traits(db) {
-                if !result.contains(&tt) {
-                    result.push(tt);
-                }
-            }
-            i += 1;
-        }
-        result
-    }
-
-    pub fn associated_type_by_name(self, db: &impl DefDatabase, name: &Name) -> Option<TypeAlias> {
-        let trait_data = db.trait_data(self.id);
-        let res =
-            trait_data.associated_types().map(TypeAlias::from).find(|t| &t.name(db) == name)?;
-        Some(res)
-    }
-
-    pub fn associated_type_by_name_including_super_traits(
-        self,
-        db: &impl HirDatabase,
-        name: &Name,
-    ) -> Option<TypeAlias> {
-        self.all_super_traits(db).into_iter().find_map(|t| t.associated_type_by_name(db, name))
-    }
-
-    pub fn trait_ref(self, db: &impl HirDatabase) -> TraitRef {
-        TraitRef::for_trait(db, self)
+        db.trait_data(self.id).items.iter().map(|(_name, it)| (*it).into()).collect()
     }
 
     pub fn is_auto(self, db: &impl DefDatabase) -> bool {
@@ -785,6 +736,11 @@ pub struct TypeAlias {
 }
 
 impl TypeAlias {
+    pub fn has_non_default_type_params(self, db: &impl HirDatabase) -> bool {
+        let subst = db.generic_defaults(self.id.into());
+        subst.iter().any(|ty| ty == &Ty::Unknown)
+    }
+
     pub fn module(self, db: &impl DefDatabase) -> Module {
         Module { id: self.id.lookup(db).module(db) }
     }
@@ -821,8 +777,8 @@ impl TypeAlias {
         db.type_alias_data(self.id).type_ref.clone()
     }
 
-    pub fn ty(self, db: &impl HirDatabase) -> Ty {
-        db.type_for_def(self.into(), Namespace::Types)
+    pub fn ty(self, db: &impl HirDatabase) -> Type {
+        Type::from_def(db, self.id.lookup(db).module(db).krate, self.id)
     }
 
     pub fn name(self, db: &impl DefDatabase) -> Name {
@@ -897,16 +853,6 @@ impl_froms!(
     Const
 );
 
-impl From<AssocItem> for GenericDef {
-    fn from(item: AssocItem) -> Self {
-        match item {
-            AssocItem::Function(f) => f.into(),
-            AssocItem::Const(c) => c.into(),
-            AssocItem::TypeAlias(t) => t.into(),
-        }
-    }
-}
-
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct Local {
     pub(crate) parent: DefWithBody,
@@ -945,9 +891,14 @@ impl Local {
         self.parent.module(db)
     }
 
-    pub fn ty(self, db: &impl HirDatabase) -> Ty {
-        let infer = db.infer(self.parent);
-        infer[self.pat_id].clone()
+    pub fn ty(self, db: &impl HirDatabase) -> Type {
+        let def = DefWithBodyId::from(self.parent);
+        let infer = db.infer(def);
+        let ty = infer[self.pat_id].clone();
+        let resolver = def.resolver(db);
+        let krate = def.module(db).krate;
+        let environment = TraitEnvironment::lower(db, &resolver);
+        Type { krate, ty: InEnvironment { value: ty, environment } }
     }
 
     pub fn source(self, db: &impl HirDatabase) -> Source<Either<ast::BindPat, ast::SelfParam>> {
@@ -960,7 +911,7 @@ impl Local {
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct GenericParam {
-    pub(crate) parent: GenericDef,
+    pub(crate) parent: GenericDefId,
     pub(crate) idx: u32,
 }
 
@@ -970,6 +921,15 @@ pub struct ImplBlock {
 }
 
 impl ImplBlock {
+    pub fn all_in_crate(db: &impl HirDatabase, krate: Crate) -> Vec<ImplBlock> {
+        let impls = db.impls_in_crate(krate.crate_id);
+        impls.all_impls().map(Self::from).collect()
+    }
+    pub fn for_trait(db: &impl HirDatabase, krate: Crate, trait_: Trait) -> Vec<ImplBlock> {
+        let impls = db.impls_in_crate(krate.crate_id);
+        impls.lookup_impl_blocks_for_trait(trait_.id).map(Self::from).collect()
+    }
+
     pub fn target_trait(&self, db: &impl DefDatabase) -> Option<TypeRef> {
         db.impl_data(self.id).target_trait.clone()
     }
@@ -978,13 +938,12 @@ impl ImplBlock {
         db.impl_data(self.id).target_type.clone()
     }
 
-    pub fn target_ty(&self, db: &impl HirDatabase) -> Ty {
-        Ty::from_hir(db, &self.id.resolver(db), &self.target_type(db))
-    }
-
-    pub fn target_trait_ref(&self, db: &impl HirDatabase) -> Option<TraitRef> {
-        let target_ty = self.target_ty(db);
-        TraitRef::from_hir(db, &self.id.resolver(db), &self.target_trait(db)?, Some(target_ty))
+    pub fn target_ty(&self, db: &impl HirDatabase) -> Type {
+        let impl_data = db.impl_data(self.id);
+        let resolver = self.id.resolver(db);
+        let environment = TraitEnvironment::lower(db, &resolver);
+        let ty = Ty::from_hir(db, &resolver, &impl_data.target_type);
+        Type { krate: self.id.module(db).krate, ty: InEnvironment { value: ty, environment } }
     }
 
     pub fn items(&self, db: &impl DefDatabase) -> Vec<AssocItem> {
@@ -1004,6 +963,194 @@ impl ImplBlock {
     }
 }
 
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct Type {
+    pub(crate) krate: CrateId,
+    pub(crate) ty: InEnvironment<Ty>,
+}
+
+impl Type {
+    fn from_def(
+        db: &impl HirDatabase,
+        krate: CrateId,
+        def: impl HasResolver + Into<TyDefId>,
+    ) -> Type {
+        let resolver = def.resolver(db);
+        let environment = TraitEnvironment::lower(db, &resolver);
+        let ty = db.ty(def.into());
+        Type { krate, ty: InEnvironment { value: ty, environment } }
+    }
+
+    pub fn is_bool(&self) -> bool {
+        match &self.ty.value {
+            Ty::Apply(a_ty) => match a_ty.ctor {
+                TypeCtor::Bool => true,
+                _ => false,
+            },
+            _ => false,
+        }
+    }
+
+    pub fn is_mutable_reference(&self) -> bool {
+        match &self.ty.value {
+            Ty::Apply(a_ty) => match a_ty.ctor {
+                TypeCtor::Ref(Mutability::Mut) => true,
+                _ => false,
+            },
+            _ => false,
+        }
+    }
+
+    pub fn is_unknown(&self) -> bool {
+        match &self.ty.value {
+            Ty::Unknown => true,
+            _ => false,
+        }
+    }
+
+    // FIXME: this method is broken, as it doesn't take closures into account.
+    pub fn as_callable(&self) -> Option<CallableDef> {
+        Some(self.ty.value.as_callable()?.0)
+    }
+
+    pub fn contains_unknown(&self) -> bool {
+        return go(&self.ty.value);
+
+        fn go(ty: &Ty) -> bool {
+            match ty {
+                Ty::Unknown => true,
+                Ty::Apply(a_ty) => a_ty.parameters.iter().any(go),
+                _ => false,
+            }
+        }
+    }
+
+    pub fn fields(&self, db: &impl HirDatabase) -> Vec<(StructField, Type)> {
+        if let Ty::Apply(a_ty) = &self.ty.value {
+            match a_ty.ctor {
+                ty::TypeCtor::Adt(AdtId::StructId(s)) => {
+                    let var_def = s.into();
+                    return db
+                        .field_types(var_def)
+                        .iter()
+                        .map(|(local_id, ty)| {
+                            let def = StructField { parent: var_def.into(), id: local_id };
+                            let ty = ty.clone().subst(&a_ty.parameters);
+                            (def, self.derived(ty))
+                        })
+                        .collect();
+                }
+                _ => {}
+            }
+        };
+        Vec::new()
+    }
+
+    pub fn tuple_fields(&self, _db: &impl HirDatabase) -> Vec<Type> {
+        let mut res = Vec::new();
+        if let Ty::Apply(a_ty) = &self.ty.value {
+            match a_ty.ctor {
+                ty::TypeCtor::Tuple { .. } => {
+                    for ty in a_ty.parameters.iter() {
+                        let ty = ty.clone().subst(&a_ty.parameters);
+                        res.push(self.derived(ty));
+                    }
+                }
+                _ => {}
+            }
+        };
+        res
+    }
+
+    pub fn variant_fields(
+        &self,
+        db: &impl HirDatabase,
+        def: VariantDef,
+    ) -> Vec<(StructField, Type)> {
+        // FIXME: check that ty and def match
+        match &self.ty.value {
+            Ty::Apply(a_ty) => def
+                .fields(db)
+                .into_iter()
+                .map(|it| (it, self.derived(it.ty(db).subst(&a_ty.parameters))))
+                .collect(),
+            _ => Vec::new(),
+        }
+    }
+
+    pub fn autoderef<'a>(&'a self, db: &'a impl HirDatabase) -> impl Iterator<Item = Type> + 'a {
+        // There should be no inference vars in types passed here
+        // FIXME check that?
+        let canonical = crate::ty::Canonical { value: self.ty.value.clone(), num_vars: 0 };
+        let environment = self.ty.environment.clone();
+        let ty = InEnvironment { value: canonical, environment: environment.clone() };
+        ty::autoderef(db, Some(self.krate), ty)
+            .map(|canonical| canonical.value)
+            .map(move |ty| self.derived(ty))
+    }
+
+    // This would be nicer if it just returned an iterator, but that runs into
+    // lifetime problems, because we need to borrow temp `CrateImplBlocks`.
+    pub fn iterate_impl_items<T>(
+        self,
+        db: &impl HirDatabase,
+        krate: Crate,
+        mut callback: impl FnMut(AssocItem) -> Option<T>,
+    ) -> Option<T> {
+        for krate in self.ty.value.def_crates(db, krate.crate_id)? {
+            let impls = db.impls_in_crate(krate);
+
+            for impl_block in impls.lookup_impl_blocks(&self.ty.value) {
+                for &item in db.impl_data(impl_block).items.iter() {
+                    if let Some(result) = callback(item.into()) {
+                        return Some(result);
+                    }
+                }
+            }
+        }
+        None
+    }
+
+    // FIXME: remove
+    pub fn into_ty(self) -> Ty {
+        self.ty.value
+    }
+
+    pub fn as_adt(&self) -> Option<Adt> {
+        let (adt, _subst) = self.ty.value.as_adt()?;
+        Some(adt.into())
+    }
+
+    // FIXME: provide required accessors such that it becomes implementable from outside.
+    pub fn is_equal_for_find_impls(&self, other: &Type) -> bool {
+        match (&self.ty.value, &other.ty.value) {
+            (Ty::Apply(a_original_ty), Ty::Apply(ty::ApplicationTy { ctor, parameters })) => {
+                match ctor {
+                    TypeCtor::Ref(..) => match parameters.as_single() {
+                        Ty::Apply(a_ty) => a_original_ty.ctor == a_ty.ctor,
+                        _ => false,
+                    },
+                    _ => a_original_ty.ctor == *ctor,
+                }
+            }
+            _ => false,
+        }
+    }
+
+    fn derived(&self, ty: Ty) -> Type {
+        Type {
+            krate: self.krate,
+            ty: InEnvironment { value: ty, environment: self.ty.environment.clone() },
+        }
+    }
+}
+
+impl HirDisplay for Type {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> std::fmt::Result {
+        self.ty.value.hir_fmt(f)
+    }
+}
+
 /// For IDE only
 pub enum ScopeDef {
     ModuleDef(ModuleDef),
diff --git a/crates/ra_hir/src/code_model/src.rs b/crates/ra_hir/src/code_model/src.rs
index a4e317c20..bf3ee0834 100644
--- a/crates/ra_hir/src/code_model/src.rs
+++ b/crates/ra_hir/src/code_model/src.rs
@@ -22,7 +22,7 @@ impl Module {
     /// Returns a node which defines this module. That is, a file or a `mod foo {}` with items.
     pub fn definition_source(self, db: &impl DefDatabase) -> Source<ModuleSource> {
         let def_map = db.crate_def_map(self.id.krate);
-        let src = def_map[self.id.module_id].definition_source(db);
+        let src = def_map[self.id.local_id].definition_source(db);
         src.map(|it| match it {
             Either::A(it) => ModuleSource::SourceFile(it),
             Either::B(it) => ModuleSource::Module(it),
@@ -33,7 +33,7 @@ impl Module {
     /// `None` for the crate root.
     pub fn declaration_source(self, db: &impl DefDatabase) -> Option<Source<ast::Module>> {
         let def_map = db.crate_def_map(self.id.krate);
-        def_map[self.id.module_id].declaration_source(db)
+        def_map[self.id.local_id].declaration_source(db)
     }
 }
 
@@ -51,13 +51,13 @@ impl HasSource for StructField {
 impl HasSource for Struct {
     type Ast = ast::StructDef;
     fn source(self, db: &impl DefDatabase) -> Source<ast::StructDef> {
-        self.id.0.source(db)
+        self.id.source(db)
     }
 }
 impl HasSource for Union {
-    type Ast = ast::StructDef;
-    fn source(self, db: &impl DefDatabase) -> Source<ast::StructDef> {
-        self.id.0.source(db)
+    type Ast = ast::UnionDef;
+    fn source(self, db: &impl DefDatabase) -> Source<ast::UnionDef> {
+        self.id.source(db)
     }
 }
 impl HasSource for Enum {
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index 5084bbacf..bfae3660b 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -1,130 +1,22 @@
 //! FIXME: write short doc here
 
-use std::sync::Arc;
-
-use ra_arena::map::ArenaMap;
-use ra_db::salsa;
-
-use crate::{
-    ty::{
-        method_resolution::CrateImplBlocks,
-        traits::{AssocTyValue, Impl},
-        CallableDef, FnSig, GenericPredicate, InferenceResult, Namespace, Substs, Ty, TypableDef,
-        TypeCtor,
-    },
-    Crate, DefWithBody, GenericDef, ImplBlock, Trait,
-};
-
-pub use hir_def::{
-    db::{
-        BodyQuery, BodyWithSourceMapQuery, ConstDataQuery, CrateDefMapQuery, CrateLangItemsQuery,
-        DefDatabase, DefDatabaseStorage, DocumentationQuery, EnumDataQuery, ExprScopesQuery,
-        FunctionDataQuery, GenericParamsQuery, ImplDataQuery, InternDatabase,
-        InternDatabaseStorage, LangItemQuery, ModuleLangItemsQuery, RawItemsQuery,
-        RawItemsWithSourceMapQuery, StaticDataQuery, StructDataQuery, TraitDataQuery,
-        TypeAliasDataQuery,
-    },
-    LocalStructFieldId, VariantId,
+pub use hir_def::db::{
+    BodyQuery, BodyWithSourceMapQuery, ConstDataQuery, CrateDefMapQuery, CrateLangItemsQuery,
+    DefDatabase, DefDatabaseStorage, DocumentationQuery, EnumDataQuery, ExprScopesQuery,
+    FunctionDataQuery, GenericParamsQuery, ImplDataQuery, InternDatabase, InternDatabaseStorage,
+    LangItemQuery, ModuleLangItemsQuery, RawItemsQuery, RawItemsWithSourceMapQuery,
+    StaticDataQuery, StructDataQuery, TraitDataQuery, TypeAliasDataQuery,
 };
 pub use hir_expand::db::{
     AstDatabase, AstDatabaseStorage, AstIdMapQuery, MacroArgQuery, MacroDefQuery, MacroExpandQuery,
     ParseMacroQuery,
 };
-
-#[salsa::query_group(HirDatabaseStorage)]
-#[salsa::requires(salsa::Database)]
-pub trait HirDatabase: DefDatabase {
-    #[salsa::invoke(crate::ty::infer_query)]
-    fn infer(&self, def: DefWithBody) -> Arc<InferenceResult>;
-
-    #[salsa::invoke(crate::ty::type_for_def)]
-    fn type_for_def(&self, def: TypableDef, ns: Namespace) -> Ty;
-
-    #[salsa::invoke(crate::ty::field_types_query)]
-    fn field_types(&self, var: VariantId) -> Arc<ArenaMap<LocalStructFieldId, Ty>>;
-
-    #[salsa::invoke(crate::ty::callable_item_sig)]
-    fn callable_item_signature(&self, def: CallableDef) -> FnSig;
-
-    #[salsa::invoke(crate::ty::generic_predicates_for_param_query)]
-    fn generic_predicates_for_param(
-        &self,
-        def: GenericDef,
-        param_idx: u32,
-    ) -> Arc<[GenericPredicate]>;
-
-    #[salsa::invoke(crate::ty::generic_predicates_query)]
-    fn generic_predicates(&self, def: GenericDef) -> Arc<[GenericPredicate]>;
-
-    #[salsa::invoke(crate::ty::generic_defaults_query)]
-    fn generic_defaults(&self, def: GenericDef) -> Substs;
-
-    #[salsa::invoke(crate::ty::method_resolution::CrateImplBlocks::impls_in_crate_query)]
-    fn impls_in_crate(&self, krate: Crate) -> Arc<CrateImplBlocks>;
-
-    #[salsa::invoke(crate::ty::traits::impls_for_trait_query)]
-    fn impls_for_trait(&self, krate: Crate, trait_: Trait) -> Arc<[ImplBlock]>;
-
-    /// This provides the Chalk trait solver instance. Because Chalk always
-    /// works from a specific crate, this query is keyed on the crate; and
-    /// because Chalk does its own internal caching, the solver is wrapped in a
-    /// Mutex and the query does an untracked read internally, to make sure the
-    /// cached state is thrown away when input facts change.
-    #[salsa::invoke(crate::ty::traits::trait_solver_query)]
-    fn trait_solver(&self, krate: Crate) -> crate::ty::traits::TraitSolver;
-
-    // Interned IDs for Chalk integration
-    #[salsa::interned]
-    fn intern_type_ctor(&self, type_ctor: TypeCtor) -> crate::ty::TypeCtorId;
-    #[salsa::interned]
-    fn intern_chalk_impl(&self, impl_: Impl) -> crate::ty::traits::GlobalImplId;
-    #[salsa::interned]
-    fn intern_assoc_ty_value(
-        &self,
-        assoc_ty_value: AssocTyValue,
-    ) -> crate::ty::traits::AssocTyValueId;
-
-    #[salsa::invoke(crate::ty::traits::chalk::associated_ty_data_query)]
-    fn associated_ty_data(
-        &self,
-        id: chalk_ir::TypeId,
-    ) -> Arc<chalk_rust_ir::AssociatedTyDatum<chalk_ir::family::ChalkIr>>;
-
-    #[salsa::invoke(crate::ty::traits::chalk::trait_datum_query)]
-    fn trait_datum(
-        &self,
-        krate: Crate,
-        trait_id: chalk_ir::TraitId,
-    ) -> Arc<chalk_rust_ir::TraitDatum<chalk_ir::family::ChalkIr>>;
-
-    #[salsa::invoke(crate::ty::traits::chalk::struct_datum_query)]
-    fn struct_datum(
-        &self,
-        krate: Crate,
-        struct_id: chalk_ir::StructId,
-    ) -> Arc<chalk_rust_ir::StructDatum<chalk_ir::family::ChalkIr>>;
-
-    #[salsa::invoke(crate::ty::traits::chalk::impl_datum_query)]
-    fn impl_datum(
-        &self,
-        krate: Crate,
-        impl_id: chalk_ir::ImplId,
-    ) -> Arc<chalk_rust_ir::ImplDatum<chalk_ir::family::ChalkIr>>;
-
-    #[salsa::invoke(crate::ty::traits::chalk::associated_ty_value_query)]
-    fn associated_ty_value(
-        &self,
-        krate: Crate,
-        id: chalk_rust_ir::AssociatedTyValueId,
-    ) -> Arc<chalk_rust_ir::AssociatedTyValue<chalk_ir::family::ChalkIr>>;
-
-    #[salsa::invoke(crate::ty::traits::trait_solve_query)]
-    fn trait_solve(
-        &self,
-        krate: Crate,
-        goal: crate::ty::Canonical<crate::ty::InEnvironment<crate::ty::Obligation>>,
-    ) -> Option<crate::ty::traits::Solution>;
-}
+pub use hir_ty::db::{
+    AssociatedTyDataQuery, CallableItemSignatureQuery, FieldTypesQuery, GenericDefaultsQuery,
+    GenericPredicatesQuery, HirDatabase, HirDatabaseStorage, ImplDatumQuery, ImplsForTraitQuery,
+    ImplsInCrateQuery, InferQuery, StructDatumQuery, TraitDatumQuery, TraitSolveQuery, TyQuery,
+    ValueTyQuery,
+};
 
 #[test]
 fn hir_database_is_object_safe() {
diff --git a/crates/ra_hir/src/diagnostics.rs b/crates/ra_hir/src/diagnostics.rs
index dafacba70..a9040ea3d 100644
--- a/crates/ra_hir/src/diagnostics.rs
+++ b/crates/ra_hir/src/diagnostics.rs
@@ -1,88 +1,4 @@
 //! FIXME: write short doc here
-
-use std::any::Any;
-
-use hir_expand::HirFileId;
-use ra_syntax::{ast, AstNode, AstPtr, SyntaxNodePtr};
-
-use crate::{db::AstDatabase, Name, Source};
-
 pub use hir_def::diagnostics::UnresolvedModule;
 pub use hir_expand::diagnostics::{AstDiagnostic, Diagnostic, DiagnosticSink};
-
-#[derive(Debug)]
-pub struct NoSuchField {
-    pub file: HirFileId,
-    pub field: AstPtr<ast::RecordField>,
-}
-
-impl Diagnostic for NoSuchField {
-    fn message(&self) -> String {
-        "no such field".to_string()
-    }
-
-    fn source(&self) -> Source<SyntaxNodePtr> {
-        Source { file_id: self.file, value: self.field.into() }
-    }
-
-    fn as_any(&self) -> &(dyn Any + Send + 'static) {
-        self
-    }
-}
-
-#[derive(Debug)]
-pub struct MissingFields {
-    pub file: HirFileId,
-    pub field_list: AstPtr<ast::RecordFieldList>,
-    pub missed_fields: Vec<Name>,
-}
-
-impl Diagnostic for MissingFields {
-    fn message(&self) -> String {
-        "fill structure fields".to_string()
-    }
-    fn source(&self) -> Source<SyntaxNodePtr> {
-        Source { file_id: self.file, value: self.field_list.into() }
-    }
-    fn as_any(&self) -> &(dyn Any + Send + 'static) {
-        self
-    }
-}
-
-impl AstDiagnostic for MissingFields {
-    type AST = ast::RecordFieldList;
-
-    fn ast(&self, db: &impl AstDatabase) -> Self::AST {
-        let root = db.parse_or_expand(self.source().file_id).unwrap();
-        let node = self.source().value.to_node(&root);
-        ast::RecordFieldList::cast(node).unwrap()
-    }
-}
-
-#[derive(Debug)]
-pub struct MissingOkInTailExpr {
-    pub file: HirFileId,
-    pub expr: AstPtr<ast::Expr>,
-}
-
-impl Diagnostic for MissingOkInTailExpr {
-    fn message(&self) -> String {
-        "wrap return expression in Ok".to_string()
-    }
-    fn source(&self) -> Source<SyntaxNodePtr> {
-        Source { file_id: self.file, value: self.expr.into() }
-    }
-    fn as_any(&self) -> &(dyn Any + Send + 'static) {
-        self
-    }
-}
-
-impl AstDiagnostic for MissingOkInTailExpr {
-    type AST = ast::Expr;
-
-    fn ast(&self, db: &impl AstDatabase) -> Self::AST {
-        let root = db.parse_or_expand(self.file).unwrap();
-        let node = self.source().value.to_node(&root);
-        ast::Expr::cast(node).unwrap()
-    }
-}
+pub use hir_ty::diagnostics::{MissingFields, MissingOkInTailExpr, NoSuchField};
diff --git a/crates/ra_hir/src/from_id.rs b/crates/ra_hir/src/from_id.rs
index 529ac8251..e96a18d12 100644
--- a/crates/ra_hir/src/from_id.rs
+++ b/crates/ra_hir/src/from_id.rs
@@ -4,14 +4,13 @@
 //! are splitting the hir.
 
 use hir_def::{
-    AdtId, AssocItemId, AttrDefId, ConstId, DefWithBodyId, EnumId, EnumVariantId, FunctionId,
-    GenericDefId, ModuleDefId, StaticId, StructFieldId, StructId, TypeAliasId, UnionId, VariantId,
+    AdtId, AssocItemId, AttrDefId, DefWithBodyId, EnumVariantId, GenericDefId, ModuleDefId,
+    StructFieldId, VariantId,
 };
 
 use crate::{
-    ty::{CallableDef, TypableDef},
-    Adt, AssocItem, AttrDef, Const, Crate, DefWithBody, EnumVariant, Function, GenericDef,
-    ModuleDef, Static, StructField, TypeAlias, VariantDef,
+    Adt, AssocItem, AttrDef, Crate, DefWithBody, EnumVariant, GenericDef, ModuleDef, StructField,
+    VariantDef,
 };
 
 impl From<ra_db::CrateId> for Crate {
@@ -138,72 +137,6 @@ impl From<GenericDef> for GenericDefId {
     }
 }
 
-impl From<GenericDefId> for GenericDef {
-    fn from(def: GenericDefId) -> Self {
-        match def {
-            GenericDefId::FunctionId(it) => GenericDef::Function(it.into()),
-            GenericDefId::AdtId(it) => GenericDef::Adt(it.into()),
-            GenericDefId::TraitId(it) => GenericDef::Trait(it.into()),
-            GenericDefId::TypeAliasId(it) => GenericDef::TypeAlias(it.into()),
-            GenericDefId::ImplId(it) => GenericDef::ImplBlock(it.into()),
-            GenericDefId::EnumVariantId(it) => GenericDef::EnumVariant(it.into()),
-            GenericDefId::ConstId(it) => GenericDef::Const(it.into()),
-        }
-    }
-}
-
-impl From<AdtId> for TypableDef {
-    fn from(id: AdtId) -> Self {
-        Adt::from(id).into()
-    }
-}
-
-impl From<StructId> for TypableDef {
-    fn from(id: StructId) -> Self {
-        AdtId::StructId(id).into()
-    }
-}
-
-impl From<UnionId> for TypableDef {
-    fn from(id: UnionId) -> Self {
-        AdtId::UnionId(id).into()
-    }
-}
-
-impl From<EnumId> for TypableDef {
-    fn from(id: EnumId) -> Self {
-        AdtId::EnumId(id).into()
-    }
-}
-
-impl From<EnumVariantId> for TypableDef {
-    fn from(id: EnumVariantId) -> Self {
-        EnumVariant::from(id).into()
-    }
-}
-
-impl From<TypeAliasId> for TypableDef {
-    fn from(id: TypeAliasId) -> Self {
-        TypeAlias::from(id).into()
-    }
-}
-
-impl From<FunctionId> for TypableDef {
-    fn from(id: FunctionId) -> Self {
-        Function::from(id).into()
-    }
-}
-impl From<ConstId> for TypableDef {
-    fn from(id: ConstId) -> Self {
-        Const::from(id).into()
-    }
-}
-impl From<StaticId> for TypableDef {
-    fn from(id: StaticId) -> Self {
-        Static::from(id).into()
-    }
-}
-
 impl From<Adt> for GenericDefId {
     fn from(id: Adt) -> Self {
         match id {
@@ -214,14 +147,12 @@ impl From<Adt> for GenericDefId {
     }
 }
 
-impl From<CallableDef> for GenericDefId {
-    fn from(def: CallableDef) -> Self {
+impl From<VariantId> for VariantDef {
+    fn from(def: VariantId) -> Self {
         match def {
-            CallableDef::Function(it) => it.id.into(),
-            CallableDef::Struct(it) => it.id.into(),
-            CallableDef::EnumVariant(it) => {
-                EnumVariantId { parent: it.parent.id, local_id: it.id }.into()
-            }
+            VariantId::StructId(it) => VariantDef::Struct(it.into()),
+            VariantId::EnumVariantId(it) => VariantDef::EnumVariant(it.into()),
+            VariantId::UnionId(it) => VariantDef::Union(it.into()),
         }
     }
 }
@@ -231,6 +162,7 @@ impl From<VariantDef> for VariantId {
         match def {
             VariantDef::Struct(it) => VariantId::StructId(it.id),
             VariantDef::EnumVariant(it) => VariantId::EnumVariantId(it.into()),
+            VariantDef::Union(it) => VariantId::UnionId(it.id),
         }
     }
 }
@@ -241,6 +173,12 @@ impl From<StructField> for StructFieldId {
     }
 }
 
+impl From<StructFieldId> for StructField {
+    fn from(def: StructFieldId) -> Self {
+        StructField { parent: def.parent.into(), id: def.local_id }
+    }
+}
+
 impl From<AttrDef> for AttrDefId {
     fn from(def: AttrDef) -> Self {
         match def {
@@ -257,3 +195,13 @@ impl From<AttrDef> for AttrDefId {
         }
     }
 }
+
+impl From<AssocItem> for GenericDefId {
+    fn from(item: AssocItem) -> Self {
+        match item {
+            AssocItem::Function(f) => f.id.into(),
+            AssocItem::Const(c) => c.id.into(),
+            AssocItem::TypeAlias(t) => t.id.into(),
+        }
+    }
+}
diff --git a/crates/ra_hir/src/from_source.rs b/crates/ra_hir/src/from_source.rs
index 1e7c22774..9f7c22b21 100644
--- a/crates/ra_hir/src/from_source.rs
+++ b/crates/ra_hir/src/from_source.rs
@@ -1,6 +1,6 @@
 //! FIXME: write short doc here
 
-use hir_def::{AstItemDef, LocationCtx, ModuleId, StructId, StructOrUnionId, UnionId};
+use hir_def::{AstItemDef, LocationCtx, ModuleId};
 use hir_expand::{name::AsName, AstId, MacroDefId, MacroDefKind};
 use ra_syntax::{
     ast::{self, AstNode, NameOwner},
@@ -19,19 +19,18 @@ pub trait FromSource: Sized {
     fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self>;
 }
 
-// FIXIME: these two impls are wrong, `ast::StructDef` might produce either a struct or a union
 impl FromSource for Struct {
     type Ast = ast::StructDef;
     fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
-        let id: StructOrUnionId = from_source(db, src)?;
-        Some(Struct { id: StructId(id) })
+        let id = from_source(db, src)?;
+        Some(Struct { id })
     }
 }
 impl FromSource for Union {
-    type Ast = ast::StructDef;
+    type Ast = ast::UnionDef;
     fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
-        let id: StructOrUnionId = from_source(db, src)?;
-        Some(Union { id: UnionId(id) })
+        let id = from_source(db, src)?;
+        Some(Union { id })
     }
 }
 impl FromSource for Enum {
@@ -263,13 +262,12 @@ impl Module {
 
         let original_file = src.file_id.original_file(db);
 
-        let (krate, module_id) =
-            db.relevant_crates(original_file).iter().find_map(|&crate_id| {
-                let crate_def_map = db.crate_def_map(crate_id);
-                let local_module_id = crate_def_map.modules_for_file(original_file).next()?;
-                Some((crate_id, local_module_id))
-            })?;
-        Some(Module { id: ModuleId { krate, module_id } })
+        let (krate, local_id) = db.relevant_crates(original_file).iter().find_map(|&crate_id| {
+            let crate_def_map = db.crate_def_map(crate_id);
+            let local_id = crate_def_map.modules_for_file(original_file).next()?;
+            Some((crate_id, local_id))
+        })?;
+        Some(Module { id: ModuleId { krate, local_id } })
     }
 }
 
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 843ce6a88..3c12c61f0 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -32,28 +32,20 @@ pub mod db;
 pub mod source_binder;
 
 mod ty;
-mod expr;
 pub mod diagnostics;
-mod util;
 
 mod from_id;
 mod code_model;
 
 pub mod from_source;
 
-#[cfg(test)]
-mod test_db;
-#[cfg(test)]
-mod marks;
-
 pub use crate::{
     code_model::{
         src::HasSource, Adt, AssocItem, AttrDef, Const, Container, Crate, CrateDependency,
         DefWithBody, Docs, Enum, EnumVariant, FieldSource, Function, GenericDef, GenericParam,
         HasAttrs, ImplBlock, Import, Local, MacroDef, Module, ModuleDef, ModuleSource, ScopeDef,
-        Static, Struct, StructField, Trait, TypeAlias, Union, VariantDef,
+        Static, Struct, StructField, Trait, Type, TypeAlias, Union, VariantDef,
     },
-    expr::ExprScopes,
     from_source::FromSource,
     source_binder::{PathResolution, ScopeEntryWithSyntax, SourceAnalyzer},
     ty::{
@@ -64,6 +56,7 @@ pub use crate::{
 };
 
 pub use hir_def::{
+    body::scope::ExprScopes,
     builtin_type::BuiltinType,
     docs::Documentation,
     path::{Path, PathKind},
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index 31390bb7f..76c493f1a 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -8,13 +8,17 @@
 use std::sync::Arc;
 
 use hir_def::{
+    body::{
+        scope::{ExprScopes, ScopeId},
+        BodySourceMap,
+    },
     expr::{ExprId, PatId},
     path::known,
     resolver::{self, resolver_for_scope, HasResolver, Resolver, TypeNs, ValueNs},
-    DefWithBodyId,
+    AssocItemId, DefWithBodyId,
 };
 use hir_expand::{
-    name::AsName, AstId, HirFileId, MacroCallId, MacroCallLoc, MacroFileKind, Source,
+    hygiene::Hygiene, name::AsName, AstId, HirFileId, MacroCallId, MacroFileKind, Source,
 };
 use ra_syntax::{
     ast::{self, AstNode},
@@ -25,10 +29,12 @@ use ra_syntax::{
 
 use crate::{
     db::HirDatabase,
-    expr::{BodySourceMap, ExprScopes, ScopeId},
-    ty::method_resolution::{self, implements_trait},
+    ty::{
+        method_resolution::{self, implements_trait},
+        InEnvironment, TraitEnvironment, Ty,
+    },
     Adt, AssocItem, Const, DefWithBody, Either, Enum, EnumVariant, FromSource, Function,
-    GenericParam, Local, MacroDef, Name, Path, ScopeDef, Static, Struct, Trait, Ty, TypeAlias,
+    GenericParam, Local, MacroDef, Name, Path, ScopeDef, Static, Struct, Trait, Type, TypeAlias,
 };
 
 fn try_get_resolver_for_node(db: &impl HirDatabase, node: Source<&SyntaxNode>) -> Option<Resolver> {
@@ -88,7 +94,7 @@ pub struct SourceAnalyzer {
     body_owner: Option<DefWithBody>,
     body_source_map: Option<Arc<BodySourceMap>>,
     infer: Option<Arc<crate::ty::InferenceResult>>,
-    scopes: Option<Arc<crate::expr::ExprScopes>>,
+    scopes: Option<Arc<ExprScopes>>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -165,7 +171,7 @@ impl SourceAnalyzer {
                 resolver,
                 body_owner: Some(def),
                 body_source_map: Some(source_map),
-                infer: Some(db.infer(def)),
+                infer: Some(db.infer(def.into())),
                 scopes: Some(scopes),
                 file_id: node.file_id,
             }
@@ -195,48 +201,52 @@ impl SourceAnalyzer {
         self.body_source_map.as_ref()?.node_pat(src)
     }
 
-    pub fn type_of(&self, _db: &impl HirDatabase, expr: &ast::Expr) -> Option<crate::Ty> {
+    pub fn type_of(&self, db: &impl HirDatabase, expr: &ast::Expr) -> Option<Type> {
         let expr_id = self.expr_id(expr)?;
-        Some(self.infer.as_ref()?[expr_id].clone())
+        let ty = self.infer.as_ref()?[expr_id].clone();
+        let environment = TraitEnvironment::lower(db, &self.resolver);
+        Some(Type { krate: self.resolver.krate()?, ty: InEnvironment { value: ty, environment } })
     }
 
-    pub fn type_of_pat(&self, _db: &impl HirDatabase, pat: &ast::Pat) -> Option<crate::Ty> {
+    pub fn type_of_pat(&self, db: &impl HirDatabase, pat: &ast::Pat) -> Option<Type> {
         let pat_id = self.pat_id(pat)?;
-        Some(self.infer.as_ref()?[pat_id].clone())
+        let ty = self.infer.as_ref()?[pat_id].clone();
+        let environment = TraitEnvironment::lower(db, &self.resolver);
+        Some(Type { krate: self.resolver.krate()?, ty: InEnvironment { value: ty, environment } })
     }
 
     pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
         let expr_id = self.expr_id(&call.clone().into())?;
-        self.infer.as_ref()?.method_resolution(expr_id)
+        self.infer.as_ref()?.method_resolution(expr_id).map(Function::from)
     }
 
     pub fn resolve_field(&self, field: &ast::FieldExpr) -> Option<crate::StructField> {
         let expr_id = self.expr_id(&field.clone().into())?;
-        self.infer.as_ref()?.field_resolution(expr_id)
+        self.infer.as_ref()?.field_resolution(expr_id).map(|it| it.into())
     }
 
     pub fn resolve_record_field(&self, field: &ast::RecordField) -> Option<crate::StructField> {
         let expr_id = self.expr_id(&field.expr()?)?;
-        self.infer.as_ref()?.record_field_resolution(expr_id)
+        self.infer.as_ref()?.record_field_resolution(expr_id).map(|it| it.into())
     }
 
     pub fn resolve_record_literal(&self, record_lit: &ast::RecordLit) -> Option<crate::VariantDef> {
         let expr_id = self.expr_id(&record_lit.clone().into())?;
-        self.infer.as_ref()?.variant_resolution_for_expr(expr_id)
+        self.infer.as_ref()?.variant_resolution_for_expr(expr_id).map(|it| it.into())
     }
 
     pub fn resolve_record_pattern(&self, record_pat: &ast::RecordPat) -> Option<crate::VariantDef> {
         let pat_id = self.pat_id(&record_pat.clone().into())?;
-        self.infer.as_ref()?.variant_resolution_for_pat(pat_id)
+        self.infer.as_ref()?.variant_resolution_for_pat(pat_id).map(|it| it.into())
     }
 
     pub fn resolve_macro_call(
         &self,
         db: &impl HirDatabase,
-        macro_call: &ast::MacroCall,
+        macro_call: Source<&ast::MacroCall>,
     ) -> Option<MacroDef> {
-        // This must be a normal source file rather than macro file.
-        let path = macro_call.path().and_then(Path::from_ast)?;
+        let hygiene = Hygiene::new(db, macro_call.file_id);
+        let path = macro_call.value.path().and_then(|ast| Path::from_src(ast, &hygiene))?;
         self.resolver.resolve_path_as_macro(db, &path).map(|it| it.into())
     }
 
@@ -248,7 +258,7 @@ impl SourceAnalyzer {
         let types = self.resolver.resolve_path_in_type_ns_fully(db, &path).map(|ty| match ty {
             TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
             TypeNs::GenericParam(idx) => PathResolution::GenericParam(GenericParam {
-                parent: self.resolver.generic_def().unwrap().into(),
+                parent: self.resolver.generic_def().unwrap(),
                 idx,
             }),
             TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => {
@@ -290,13 +300,13 @@ impl SourceAnalyzer {
         if let Some(path_expr) = path.syntax().parent().and_then(ast::PathExpr::cast) {
             let expr_id = self.expr_id(&path_expr.into())?;
             if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_expr(expr_id) {
-                return Some(PathResolution::AssocItem(assoc));
+                return Some(PathResolution::AssocItem(assoc.into()));
             }
         }
         if let Some(path_pat) = path.syntax().parent().and_then(ast::PathPat::cast) {
             let pat_id = self.pat_id(&path_pat.into())?;
             if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_pat(pat_id) {
-                return Some(PathResolution::AssocItem(assoc));
+                return Some(PathResolution::AssocItem(assoc.into()));
             }
         }
         // This must be a normal source file rather than macro file.
@@ -323,7 +333,7 @@ impl SourceAnalyzer {
                 resolver::ScopeDef::ImplSelfType(it) => ScopeDef::ImplSelfType(it.into()),
                 resolver::ScopeDef::AdtSelfType(it) => ScopeDef::AdtSelfType(it.into()),
                 resolver::ScopeDef::GenericParam(idx) => {
-                    let parent = self.resolver.generic_def().unwrap().into();
+                    let parent = self.resolver.generic_def().unwrap();
                     ScopeDef::GenericParam(GenericParam { parent, idx })
                 }
                 resolver::ScopeDef::Local(pat_id) => {
@@ -358,14 +368,14 @@ impl SourceAnalyzer {
     pub fn iterate_method_candidates<T>(
         &self,
         db: &impl HirDatabase,
-        ty: Ty,
+        ty: &Type,
         name: Option<&Name>,
         mut callback: impl FnMut(&Ty, Function) -> Option<T>,
     ) -> Option<T> {
         // There should be no inference vars in types passed here
         // FIXME check that?
         // FIXME replace Unknown by bound vars here
-        let canonical = crate::ty::Canonical { value: ty, num_vars: 0 };
+        let canonical = crate::ty::Canonical { value: ty.ty.value.clone(), num_vars: 0 };
         method_resolution::iterate_method_candidates(
             &canonical,
             db,
@@ -373,7 +383,7 @@ impl SourceAnalyzer {
             name,
             method_resolution::LookupMode::MethodCall,
             |ty, it| match it {
-                AssocItem::Function(f) => callback(ty, f),
+                AssocItemId::FunctionId(f) => callback(ty, f.into()),
                 _ => None,
             },
         )
@@ -382,34 +392,37 @@ impl SourceAnalyzer {
     pub fn iterate_path_candidates<T>(
         &self,
         db: &impl HirDatabase,
-        ty: Ty,
+        ty: &Type,
         name: Option<&Name>,
-        callback: impl FnMut(&Ty, AssocItem) -> Option<T>,
+        mut callback: impl FnMut(&Ty, AssocItem) -> Option<T>,
     ) -> Option<T> {
         // There should be no inference vars in types passed here
         // FIXME check that?
         // FIXME replace Unknown by bound vars here
-        let canonical = crate::ty::Canonical { value: ty, num_vars: 0 };
+        let canonical = crate::ty::Canonical { value: ty.ty.value.clone(), num_vars: 0 };
         method_resolution::iterate_method_candidates(
             &canonical,
             db,
             &self.resolver,
             name,
             method_resolution::LookupMode::Path,
-            callback,
+            |ty, it| callback(ty, it.into()),
         )
     }
 
-    pub fn autoderef<'a>(
-        &'a self,
-        db: &'a impl HirDatabase,
-        ty: Ty,
-    ) -> impl Iterator<Item = Ty> + 'a {
-        // There should be no inference vars in types passed here
-        // FIXME check that?
-        let canonical = crate::ty::Canonical { value: ty, num_vars: 0 };
-        crate::ty::autoderef(db, &self.resolver, canonical).map(|canonical| canonical.value)
-    }
+    // pub fn autoderef<'a>(
+    //     &'a self,
+    //     db: &'a impl HirDatabase,
+    //     ty: Ty,
+    // ) -> impl Iterator<Item = Ty> + 'a {
+    //     // There should be no inference vars in types passed here
+    //     // FIXME check that?
+    //     let canonical = crate::ty::Canonical { value: ty, num_vars: 0 };
+    //     let krate = self.resolver.krate();
+    //     let environment = TraitEnvironment::lower(db, &self.resolver);
+    //     let ty = crate::ty::InEnvironment { value: canonical, environment };
+    //     crate::ty::autoderef(db, krate, ty).map(|canonical| canonical.value)
+    // }
 
     /// Checks that particular type `ty` implements `std::future::Future`.
     /// This function is used in `.await` syntax completion.
@@ -435,32 +448,16 @@ impl SourceAnalyzer {
         db: &impl HirDatabase,
         macro_call: Source<&ast::MacroCall>,
     ) -> Option<Expansion> {
-        let def = self.resolve_macro_call(db, macro_call.value)?.id;
+        let def = self.resolve_macro_call(db, macro_call)?.id;
         let ast_id = AstId::new(
             macro_call.file_id,
             db.ast_id_map(macro_call.file_id).ast_id(macro_call.value),
         );
-        let macro_call_loc = MacroCallLoc { def, ast_id };
         Some(Expansion {
-            macro_call_id: db.intern_macro(macro_call_loc),
+            macro_call_id: def.as_call_id(db, ast_id),
             macro_file_kind: to_macro_file_kind(macro_call.value),
         })
     }
-
-    #[cfg(test)]
-    pub(crate) fn body_source_map(&self) -> Arc<BodySourceMap> {
-        self.body_source_map.clone().unwrap()
-    }
-
-    #[cfg(test)]
-    pub(crate) fn inference_result(&self) -> Arc<crate::ty::InferenceResult> {
-        self.infer.clone().unwrap()
-    }
-
-    #[cfg(test)]
-    pub(crate) fn analyzed_declaration(&self) -> Option<DefWithBody> {
-        self.body_owner
-    }
 }
 
 fn scope_for(
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index f62316c1f..4ed69c00d 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -1,1094 +1,4 @@
 //! The type system. We currently use this to infer types for completion, hover
 //! information and various assists.
 
-mod autoderef;
-pub(crate) mod primitive;
-pub(crate) mod traits;
-pub(crate) mod method_resolution;
-mod op;
-mod lower;
-mod infer;
-pub(crate) mod display;
-
-#[cfg(test)]
-mod tests;
-
-use std::ops::Deref;
-use std::sync::Arc;
-use std::{fmt, iter, mem};
-
-use hir_def::{generics::GenericParams, AdtId};
-use ra_db::{impl_intern_key, salsa};
-
-use crate::{
-    db::HirDatabase, expr::ExprId, util::make_mut_slice, Adt, Crate, DefWithBody, FloatTy,
-    GenericDef, IntTy, Mutability, Name, Trait, TypeAlias, Uncertain,
-};
-use display::{HirDisplay, HirFormatter};
-
-pub(crate) use autoderef::autoderef;
-pub(crate) use infer::{infer_query, InferTy, InferenceResult};
-pub use lower::CallableDef;
-pub(crate) use lower::{
-    callable_item_sig, field_types_query, generic_defaults_query,
-    generic_predicates_for_param_query, generic_predicates_query, type_for_def, Namespace,
-    TypableDef,
-};
-pub(crate) use traits::{InEnvironment, Obligation, ProjectionPredicate, TraitEnvironment};
-
-/// A type constructor or type name: this might be something like the primitive
-/// type `bool`, a struct like `Vec`, or things like function pointers or
-/// tuples.
-#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
-pub enum TypeCtor {
-    /// The primitive boolean type. Written as `bool`.
-    Bool,
-
-    /// The primitive character type; holds a Unicode scalar value
-    /// (a non-surrogate code point). Written as `char`.
-    Char,
-
-    /// A primitive integer type. For example, `i32`.
-    Int(Uncertain<IntTy>),
-
-    /// A primitive floating-point type. For example, `f64`.
-    Float(Uncertain<FloatTy>),
-
-    /// Structures, enumerations and unions.
-    Adt(Adt),
-
-    /// The pointee of a string slice. Written as `str`.
-    Str,
-
-    /// The pointee of an array slice.  Written as `[T]`.
-    Slice,
-
-    /// An array with the given length. Written as `[T; n]`.
-    Array,
-
-    /// A raw pointer. Written as `*mut T` or `*const T`
-    RawPtr(Mutability),
-
-    /// A reference; a pointer with an associated lifetime. Written as
-    /// `&'a mut T` or `&'a T`.
-    Ref(Mutability),
-
-    /// The anonymous type of a function declaration/definition. Each
-    /// function has a unique type, which is output (for a function
-    /// named `foo` returning an `i32`) as `fn() -> i32 {foo}`.
-    ///
-    /// This includes tuple struct / enum variant constructors as well.
-    ///
-    /// For example the type of `bar` here:
-    ///
-    /// ```
-    /// fn foo() -> i32 { 1 }
-    /// let bar = foo; // bar: fn() -> i32 {foo}
-    /// ```
-    FnDef(CallableDef),
-
-    /// A pointer to a function.  Written as `fn() -> i32`.
-    ///
-    /// For example the type of `bar` here:
-    ///
-    /// ```
-    /// fn foo() -> i32 { 1 }
-    /// let bar: fn() -> i32 = foo;
-    /// ```
-    FnPtr { num_args: u16 },
-
-    /// The never type `!`.
-    Never,
-
-    /// A tuple type.  For example, `(i32, bool)`.
-    Tuple { cardinality: u16 },
-
-    /// Represents an associated item like `Iterator::Item`.  This is used
-    /// when we have tried to normalize a projection like `T::Item` but
-    /// couldn't find a better representation.  In that case, we generate
-    /// an **application type** like `(Iterator::Item)<T>`.
-    AssociatedType(TypeAlias),
-
-    /// The type of a specific closure.
-    ///
-    /// The closure signature is stored in a `FnPtr` type in the first type
-    /// parameter.
-    Closure { def: DefWithBody, expr: ExprId },
-}
-
-/// This exists just for Chalk, because Chalk just has a single `StructId` where
-/// we have different kinds of ADTs, primitive types and special type
-/// constructors like tuples and function pointers.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct TypeCtorId(salsa::InternId);
-impl_intern_key!(TypeCtorId);
-
-impl TypeCtor {
-    pub fn num_ty_params(self, db: &impl HirDatabase) -> usize {
-        match self {
-            TypeCtor::Bool
-            | TypeCtor::Char
-            | TypeCtor::Int(_)
-            | TypeCtor::Float(_)
-            | TypeCtor::Str
-            | TypeCtor::Never => 0,
-            TypeCtor::Slice
-            | TypeCtor::Array
-            | TypeCtor::RawPtr(_)
-            | TypeCtor::Ref(_)
-            | TypeCtor::Closure { .. } // 1 param representing the signature of the closure
-            => 1,
-            TypeCtor::Adt(adt) => {
-                let generic_params = db.generic_params(AdtId::from(adt).into());
-                generic_params.count_params_including_parent()
-            }
-            TypeCtor::FnDef(callable) => {
-                let generic_params = db.generic_params(callable.into());
-                generic_params.count_params_including_parent()
-            }
-            TypeCtor::AssociatedType(type_alias) => {
-                let generic_params = db.generic_params(type_alias.id.into());
-                generic_params.count_params_including_parent()
-            }
-            TypeCtor::FnPtr { num_args } => num_args as usize + 1,
-            TypeCtor::Tuple { cardinality } => cardinality as usize,
-        }
-    }
-
-    pub fn krate(self, db: &impl HirDatabase) -> Option<Crate> {
-        match self {
-            TypeCtor::Bool
-            | TypeCtor::Char
-            | TypeCtor::Int(_)
-            | TypeCtor::Float(_)
-            | TypeCtor::Str
-            | TypeCtor::Never
-            | TypeCtor::Slice
-            | TypeCtor::Array
-            | TypeCtor::RawPtr(_)
-            | TypeCtor::Ref(_)
-            | TypeCtor::FnPtr { .. }
-            | TypeCtor::Tuple { .. } => None,
-            TypeCtor::Closure { def, .. } => def.krate(db),
-            TypeCtor::Adt(adt) => adt.krate(db),
-            TypeCtor::FnDef(callable) => callable.krate(db),
-            TypeCtor::AssociatedType(type_alias) => type_alias.krate(db),
-        }
-    }
-
-    pub fn as_generic_def(self) -> Option<crate::GenericDef> {
-        match self {
-            TypeCtor::Bool
-            | TypeCtor::Char
-            | TypeCtor::Int(_)
-            | TypeCtor::Float(_)
-            | TypeCtor::Str
-            | TypeCtor::Never
-            | TypeCtor::Slice
-            | TypeCtor::Array
-            | TypeCtor::RawPtr(_)
-            | TypeCtor::Ref(_)
-            | TypeCtor::FnPtr { .. }
-            | TypeCtor::Tuple { .. }
-            | TypeCtor::Closure { .. } => None,
-            TypeCtor::Adt(adt) => Some(adt.into()),
-            TypeCtor::FnDef(callable) => Some(callable.into()),
-            TypeCtor::AssociatedType(type_alias) => Some(type_alias.into()),
-        }
-    }
-}
-
-/// A nominal type with (maybe 0) type parameters. This might be a primitive
-/// type like `bool`, a struct, tuple, function pointer, reference or
-/// several other things.
-#[derive(Clone, PartialEq, Eq, Debug, Hash)]
-pub struct ApplicationTy {
-    pub ctor: TypeCtor,
-    pub parameters: Substs,
-}
-
-/// A "projection" type corresponds to an (unnormalized)
-/// projection like `<P0 as Trait<P1..Pn>>::Foo`. Note that the
-/// trait and all its parameters are fully known.
-#[derive(Clone, PartialEq, Eq, Debug, Hash)]
-pub struct ProjectionTy {
-    pub associated_ty: TypeAlias,
-    pub parameters: Substs,
-}
-
-impl ProjectionTy {
-    pub fn trait_ref(&self, db: &impl HirDatabase) -> TraitRef {
-        TraitRef {
-            trait_: self
-                .associated_ty
-                .parent_trait(db)
-                .expect("projection ty without parent trait"),
-            substs: self.parameters.clone(),
-        }
-    }
-}
-
-impl TypeWalk for ProjectionTy {
-    fn walk(&self, f: &mut impl FnMut(&Ty)) {
-        self.parameters.walk(f);
-    }
-
-    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
-        self.parameters.walk_mut_binders(f, binders);
-    }
-}
-
-/// A type.
-///
-/// See also the `TyKind` enum in rustc (librustc/ty/sty.rs), which represents
-/// the same thing (but in a different way).
-///
-/// This should be cheap to clone.
-#[derive(Clone, PartialEq, Eq, Debug, Hash)]
-pub enum Ty {
-    /// A nominal type with (maybe 0) type parameters. This might be a primitive
-    /// type like `bool`, a struct, tuple, function pointer, reference or
-    /// several other things.
-    Apply(ApplicationTy),
-
-    /// A "projection" type corresponds to an (unnormalized)
-    /// projection like `<P0 as Trait<P1..Pn>>::Foo`. Note that the
-    /// trait and all its parameters are fully known.
-    Projection(ProjectionTy),
-
-    /// A type parameter; for example, `T` in `fn f<T>(x: T) {}
-    Param {
-        /// The index of the parameter (starting with parameters from the
-        /// surrounding impl, then the current function).
-        idx: u32,
-        /// The name of the parameter, for displaying.
-        // FIXME get rid of this
-        name: Name,
-    },
-
-    /// A bound type variable. Used during trait resolution to represent Chalk
-    /// variables, and in `Dyn` and `Opaque` bounds to represent the `Self` type.
-    Bound(u32),
-
-    /// A type variable used during type checking. Not to be confused with a
-    /// type parameter.
-    Infer(InferTy),
-
-    /// A trait object (`dyn Trait` or bare `Trait` in pre-2018 Rust).
-    ///
-    /// The predicates are quantified over the `Self` type, i.e. `Ty::Bound(0)`
-    /// represents the `Self` type inside the bounds. This is currently
-    /// implicit; Chalk has the `Binders` struct to make it explicit, but it
-    /// didn't seem worth the overhead yet.
-    Dyn(Arc<[GenericPredicate]>),
-
-    /// An opaque type (`impl Trait`).
-    ///
-    /// The predicates are quantified over the `Self` type; see `Ty::Dyn` for
-    /// more.
-    Opaque(Arc<[GenericPredicate]>),
-
-    /// A placeholder for a type which could not be computed; this is propagated
-    /// to avoid useless error messages. Doubles as a placeholder where type
-    /// variables are inserted before type checking, since we want to try to
-    /// infer a better type here anyway -- for the IDE use case, we want to try
-    /// to infer as much as possible even in the presence of type errors.
-    Unknown,
-}
-
-/// A list of substitutions for generic parameters.
-#[derive(Clone, PartialEq, Eq, Debug, Hash)]
-pub struct Substs(Arc<[Ty]>);
-
-impl TypeWalk for Substs {
-    fn walk(&self, f: &mut impl FnMut(&Ty)) {
-        for t in self.0.iter() {
-            t.walk(f);
-        }
-    }
-
-    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
-        for t in make_mut_slice(&mut self.0) {
-            t.walk_mut_binders(f, binders);
-        }
-    }
-}
-
-impl Substs {
-    pub fn empty() -> Substs {
-        Substs(Arc::new([]))
-    }
-
-    pub fn single(ty: Ty) -> Substs {
-        Substs(Arc::new([ty]))
-    }
-
-    pub fn prefix(&self, n: usize) -> Substs {
-        Substs(self.0[..std::cmp::min(self.0.len(), n)].into())
-    }
-
-    pub fn as_single(&self) -> &Ty {
-        if self.0.len() != 1 {
-            panic!("expected substs of len 1, got {:?}", self);
-        }
-        &self.0[0]
-    }
-
-    /// Return Substs that replace each parameter by itself (i.e. `Ty::Param`).
-    pub fn identity(generic_params: &GenericParams) -> Substs {
-        Substs(
-            generic_params
-                .params_including_parent()
-                .into_iter()
-                .map(|p| Ty::Param { idx: p.idx, name: p.name.clone() })
-                .collect(),
-        )
-    }
-
-    /// Return Substs that replace each parameter by a bound variable.
-    pub fn bound_vars(generic_params: &GenericParams) -> Substs {
-        Substs(
-            generic_params
-                .params_including_parent()
-                .into_iter()
-                .map(|p| Ty::Bound(p.idx))
-                .collect(),
-        )
-    }
-
-    pub fn build_for_def(db: &impl HirDatabase, def: impl Into<GenericDef>) -> SubstsBuilder {
-        let def = def.into();
-        let params = db.generic_params(def.into());
-        let param_count = params.count_params_including_parent();
-        Substs::builder(param_count)
-    }
-
-    pub fn build_for_generics(generic_params: &GenericParams) -> SubstsBuilder {
-        Substs::builder(generic_params.count_params_including_parent())
-    }
-
-    pub fn build_for_type_ctor(db: &impl HirDatabase, type_ctor: TypeCtor) -> SubstsBuilder {
-        Substs::builder(type_ctor.num_ty_params(db))
-    }
-
-    fn builder(param_count: usize) -> SubstsBuilder {
-        SubstsBuilder { vec: Vec::with_capacity(param_count), param_count }
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct SubstsBuilder {
-    vec: Vec<Ty>,
-    param_count: usize,
-}
-
-impl SubstsBuilder {
-    pub fn build(self) -> Substs {
-        assert_eq!(self.vec.len(), self.param_count);
-        Substs(self.vec.into())
-    }
-
-    pub fn push(mut self, ty: Ty) -> Self {
-        self.vec.push(ty);
-        self
-    }
-
-    fn remaining(&self) -> usize {
-        self.param_count - self.vec.len()
-    }
-
-    pub fn fill_with_bound_vars(self, starting_from: u32) -> Self {
-        self.fill((starting_from..).map(Ty::Bound))
-    }
-
-    pub fn fill_with_params(self) -> Self {
-        let start = self.vec.len() as u32;
-        self.fill((start..).map(|idx| Ty::Param { idx, name: Name::missing() }))
-    }
-
-    pub fn fill_with_unknown(self) -> Self {
-        self.fill(iter::repeat(Ty::Unknown))
-    }
-
-    pub fn fill(mut self, filler: impl Iterator<Item = Ty>) -> Self {
-        self.vec.extend(filler.take(self.remaining()));
-        assert_eq!(self.remaining(), 0);
-        self
-    }
-
-    pub fn use_parent_substs(mut self, parent_substs: &Substs) -> Self {
-        assert!(self.vec.is_empty());
-        assert!(parent_substs.len() <= self.param_count);
-        self.vec.extend(parent_substs.iter().cloned());
-        self
-    }
-}
-
-impl Deref for Substs {
-    type Target = [Ty];
-
-    fn deref(&self) -> &[Ty] {
-        &self.0
-    }
-}
-
-/// A trait with type parameters. This includes the `Self`, so this represents a concrete type implementing the trait.
-/// Name to be bikeshedded: TraitBound? TraitImplements?
-#[derive(Clone, PartialEq, Eq, Debug, Hash)]
-pub struct TraitRef {
-    /// FIXME name?
-    pub trait_: Trait,
-    pub substs: Substs,
-}
-
-impl TraitRef {
-    pub fn self_ty(&self) -> &Ty {
-        &self.substs[0]
-    }
-}
-
-impl TypeWalk for TraitRef {
-    fn walk(&self, f: &mut impl FnMut(&Ty)) {
-        self.substs.walk(f);
-    }
-
-    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
-        self.substs.walk_mut_binders(f, binders);
-    }
-}
-
-/// Like `generics::WherePredicate`, but with resolved types: A condition on the
-/// parameters of a generic item.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum GenericPredicate {
-    /// The given trait needs to be implemented for its type parameters.
-    Implemented(TraitRef),
-    /// An associated type bindings like in `Iterator<Item = T>`.
-    Projection(ProjectionPredicate),
-    /// We couldn't resolve the trait reference. (If some type parameters can't
-    /// be resolved, they will just be Unknown).
-    Error,
-}
-
-impl GenericPredicate {
-    pub fn is_error(&self) -> bool {
-        match self {
-            GenericPredicate::Error => true,
-            _ => false,
-        }
-    }
-
-    pub fn is_implemented(&self) -> bool {
-        match self {
-            GenericPredicate::Implemented(_) => true,
-            _ => false,
-        }
-    }
-
-    pub fn trait_ref(&self, db: &impl HirDatabase) -> Option<TraitRef> {
-        match self {
-            GenericPredicate::Implemented(tr) => Some(tr.clone()),
-            GenericPredicate::Projection(proj) => Some(proj.projection_ty.trait_ref(db)),
-            GenericPredicate::Error => None,
-        }
-    }
-}
-
-impl TypeWalk for GenericPredicate {
-    fn walk(&self, f: &mut impl FnMut(&Ty)) {
-        match self {
-            GenericPredicate::Implemented(trait_ref) => trait_ref.walk(f),
-            GenericPredicate::Projection(projection_pred) => projection_pred.walk(f),
-            GenericPredicate::Error => {}
-        }
-    }
-
-    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
-        match self {
-            GenericPredicate::Implemented(trait_ref) => trait_ref.walk_mut_binders(f, binders),
-            GenericPredicate::Projection(projection_pred) => {
-                projection_pred.walk_mut_binders(f, binders)
-            }
-            GenericPredicate::Error => {}
-        }
-    }
-}
-
-/// Basically a claim (currently not validated / checked) that the contained
-/// type / trait ref contains no inference variables; any inference variables it
-/// contained have been replaced by bound variables, and `num_vars` tells us how
-/// many there are. This is used to erase irrelevant differences between types
-/// before using them in queries.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct Canonical<T> {
-    pub value: T,
-    pub num_vars: usize,
-}
-
-/// A function signature as seen by type inference: Several parameter types and
-/// one return type.
-#[derive(Clone, PartialEq, Eq, Debug)]
-pub struct FnSig {
-    params_and_return: Arc<[Ty]>,
-}
-
-impl FnSig {
-    pub fn from_params_and_return(mut params: Vec<Ty>, ret: Ty) -> FnSig {
-        params.push(ret);
-        FnSig { params_and_return: params.into() }
-    }
-
-    pub fn from_fn_ptr_substs(substs: &Substs) -> FnSig {
-        FnSig { params_and_return: Arc::clone(&substs.0) }
-    }
-
-    pub fn params(&self) -> &[Ty] {
-        &self.params_and_return[0..self.params_and_return.len() - 1]
-    }
-
-    pub fn ret(&self) -> &Ty {
-        &self.params_and_return[self.params_and_return.len() - 1]
-    }
-}
-
-impl TypeWalk for FnSig {
-    fn walk(&self, f: &mut impl FnMut(&Ty)) {
-        for t in self.params_and_return.iter() {
-            t.walk(f);
-        }
-    }
-
-    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
-        for t in make_mut_slice(&mut self.params_and_return) {
-            t.walk_mut_binders(f, binders);
-        }
-    }
-}
-
-impl Ty {
-    pub fn simple(ctor: TypeCtor) -> Ty {
-        Ty::Apply(ApplicationTy { ctor, parameters: Substs::empty() })
-    }
-    pub fn apply_one(ctor: TypeCtor, param: Ty) -> Ty {
-        Ty::Apply(ApplicationTy { ctor, parameters: Substs::single(param) })
-    }
-    pub fn apply(ctor: TypeCtor, parameters: Substs) -> Ty {
-        Ty::Apply(ApplicationTy { ctor, parameters })
-    }
-    pub fn unit() -> Self {
-        Ty::apply(TypeCtor::Tuple { cardinality: 0 }, Substs::empty())
-    }
-
-    pub fn as_reference(&self) -> Option<(&Ty, Mutability)> {
-        match self {
-            Ty::Apply(ApplicationTy { ctor: TypeCtor::Ref(mutability), parameters }) => {
-                Some((parameters.as_single(), *mutability))
-            }
-            _ => None,
-        }
-    }
-
-    pub fn as_adt(&self) -> Option<(Adt, &Substs)> {
-        match self {
-            Ty::Apply(ApplicationTy { ctor: TypeCtor::Adt(adt_def), parameters }) => {
-                Some((*adt_def, parameters))
-            }
-            _ => None,
-        }
-    }
-
-    pub fn as_tuple(&self) -> Option<&Substs> {
-        match self {
-            Ty::Apply(ApplicationTy { ctor: TypeCtor::Tuple { .. }, parameters }) => {
-                Some(parameters)
-            }
-            _ => None,
-        }
-    }
-
-    pub fn as_callable(&self) -> Option<(CallableDef, &Substs)> {
-        match self {
-            Ty::Apply(ApplicationTy { ctor: TypeCtor::FnDef(callable_def), parameters }) => {
-                Some((*callable_def, parameters))
-            }
-            _ => None,
-        }
-    }
-
-    fn builtin_deref(&self) -> Option<Ty> {
-        match self {
-            Ty::Apply(a_ty) => match a_ty.ctor {
-                TypeCtor::Ref(..) => Some(Ty::clone(a_ty.parameters.as_single())),
-                TypeCtor::RawPtr(..) => Some(Ty::clone(a_ty.parameters.as_single())),
-                _ => None,
-            },
-            _ => None,
-        }
-    }
-
-    fn callable_sig(&self, db: &impl HirDatabase) -> Option<FnSig> {
-        match self {
-            Ty::Apply(a_ty) => match a_ty.ctor {
-                TypeCtor::FnPtr { .. } => Some(FnSig::from_fn_ptr_substs(&a_ty.parameters)),
-                TypeCtor::FnDef(def) => {
-                    let sig = db.callable_item_signature(def);
-                    Some(sig.subst(&a_ty.parameters))
-                }
-                TypeCtor::Closure { .. } => {
-                    let sig_param = &a_ty.parameters[0];
-                    sig_param.callable_sig(db)
-                }
-                _ => None,
-            },
-            _ => None,
-        }
-    }
-
-    /// If this is a type with type parameters (an ADT or function), replaces
-    /// the `Substs` for these type parameters with the given ones. (So e.g. if
-    /// `self` is `Option<_>` and the substs contain `u32`, we'll have
-    /// `Option<u32>` afterwards.)
-    pub fn apply_substs(self, substs: Substs) -> Ty {
-        match self {
-            Ty::Apply(ApplicationTy { ctor, parameters: previous_substs }) => {
-                assert_eq!(previous_substs.len(), substs.len());
-                Ty::Apply(ApplicationTy { ctor, parameters: substs })
-            }
-            _ => self,
-        }
-    }
-
-    /// Returns the type parameters of this type if it has some (i.e. is an ADT
-    /// or function); so if `self` is `Option<u32>`, this returns the `u32`.
-    pub fn substs(&self) -> Option<Substs> {
-        match self {
-            Ty::Apply(ApplicationTy { parameters, .. }) => Some(parameters.clone()),
-            _ => None,
-        }
-    }
-
-    /// If this is an `impl Trait` or `dyn Trait`, returns that trait.
-    pub fn inherent_trait(&self) -> Option<Trait> {
-        match self {
-            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
-                predicates.iter().find_map(|pred| match pred {
-                    GenericPredicate::Implemented(tr) => Some(tr.trait_),
-                    _ => None,
-                })
-            }
-            _ => None,
-        }
-    }
-}
-
-/// This allows walking structures that contain types to do something with those
-/// types, similar to Chalk's `Fold` trait.
-pub trait TypeWalk {
-    fn walk(&self, f: &mut impl FnMut(&Ty));
-    fn walk_mut(&mut self, f: &mut impl FnMut(&mut Ty)) {
-        self.walk_mut_binders(&mut |ty, _binders| f(ty), 0);
-    }
-    /// Walk the type, counting entered binders.
-    ///
-    /// `Ty::Bound` variables use DeBruijn indexing, which means that 0 refers
-    /// to the innermost binder, 1 to the next, etc.. So when we want to
-    /// substitute a certain bound variable, we can't just walk the whole type
-    /// and blindly replace each instance of a certain index; when we 'enter'
-    /// things that introduce new bound variables, we have to keep track of
-    /// that. Currently, the only thing that introduces bound variables on our
-    /// side are `Ty::Dyn` and `Ty::Opaque`, which each introduce a bound
-    /// variable for the self type.
-    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize);
-
-    fn fold(mut self, f: &mut impl FnMut(Ty) -> Ty) -> Self
-    where
-        Self: Sized,
-    {
-        self.walk_mut(&mut |ty_mut| {
-            let ty = mem::replace(ty_mut, Ty::Unknown);
-            *ty_mut = f(ty);
-        });
-        self
-    }
-
-    /// Replaces type parameters in this type using the given `Substs`. (So e.g.
-    /// if `self` is `&[T]`, where type parameter T has index 0, and the
-    /// `Substs` contain `u32` at index 0, we'll have `&[u32]` afterwards.)
-    fn subst(self, substs: &Substs) -> Self
-    where
-        Self: Sized,
-    {
-        self.fold(&mut |ty| match ty {
-            Ty::Param { idx, name } => {
-                substs.get(idx as usize).cloned().unwrap_or(Ty::Param { idx, name })
-            }
-            ty => ty,
-        })
-    }
-
-    /// Substitutes `Ty::Bound` vars (as opposed to type parameters).
-    fn subst_bound_vars(mut self, substs: &Substs) -> Self
-    where
-        Self: Sized,
-    {
-        self.walk_mut_binders(
-            &mut |ty, binders| match ty {
-                &mut Ty::Bound(idx) => {
-                    if idx as usize >= binders && (idx as usize - binders) < substs.len() {
-                        *ty = substs.0[idx as usize - binders].clone();
-                    }
-                }
-                _ => {}
-            },
-            0,
-        );
-        self
-    }
-
-    /// Shifts up `Ty::Bound` vars by `n`.
-    fn shift_bound_vars(self, n: i32) -> Self
-    where
-        Self: Sized,
-    {
-        self.fold(&mut |ty| match ty {
-            Ty::Bound(idx) => {
-                assert!(idx as i32 >= -n);
-                Ty::Bound((idx as i32 + n) as u32)
-            }
-            ty => ty,
-        })
-    }
-}
-
-impl TypeWalk for Ty {
-    fn walk(&self, f: &mut impl FnMut(&Ty)) {
-        match self {
-            Ty::Apply(a_ty) => {
-                for t in a_ty.parameters.iter() {
-                    t.walk(f);
-                }
-            }
-            Ty::Projection(p_ty) => {
-                for t in p_ty.parameters.iter() {
-                    t.walk(f);
-                }
-            }
-            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
-                for p in predicates.iter() {
-                    p.walk(f);
-                }
-            }
-            Ty::Param { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
-        }
-        f(self);
-    }
-
-    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
-        match self {
-            Ty::Apply(a_ty) => {
-                a_ty.parameters.walk_mut_binders(f, binders);
-            }
-            Ty::Projection(p_ty) => {
-                p_ty.parameters.walk_mut_binders(f, binders);
-            }
-            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
-                for p in make_mut_slice(predicates) {
-                    p.walk_mut_binders(f, binders + 1);
-                }
-            }
-            Ty::Param { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
-        }
-        f(self, binders);
-    }
-}
-
-impl HirDisplay for &Ty {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        HirDisplay::hir_fmt(*self, f)
-    }
-}
-
-impl HirDisplay for ApplicationTy {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        if f.should_truncate() {
-            return write!(f, "…");
-        }
-
-        match self.ctor {
-            TypeCtor::Bool => write!(f, "bool")?,
-            TypeCtor::Char => write!(f, "char")?,
-            TypeCtor::Int(t) => write!(f, "{}", t)?,
-            TypeCtor::Float(t) => write!(f, "{}", t)?,
-            TypeCtor::Str => write!(f, "str")?,
-            TypeCtor::Slice => {
-                let t = self.parameters.as_single();
-                write!(f, "[{}]", t.display(f.db))?;
-            }
-            TypeCtor::Array => {
-                let t = self.parameters.as_single();
-                write!(f, "[{};_]", t.display(f.db))?;
-            }
-            TypeCtor::RawPtr(m) => {
-                let t = self.parameters.as_single();
-                write!(f, "*{}{}", m.as_keyword_for_ptr(), t.display(f.db))?;
-            }
-            TypeCtor::Ref(m) => {
-                let t = self.parameters.as_single();
-                write!(f, "&{}{}", m.as_keyword_for_ref(), t.display(f.db))?;
-            }
-            TypeCtor::Never => write!(f, "!")?,
-            TypeCtor::Tuple { .. } => {
-                let ts = &self.parameters;
-                if ts.len() == 1 {
-                    write!(f, "({},)", ts[0].display(f.db))?;
-                } else {
-                    write!(f, "(")?;
-                    f.write_joined(&*ts.0, ", ")?;
-                    write!(f, ")")?;
-                }
-            }
-            TypeCtor::FnPtr { .. } => {
-                let sig = FnSig::from_fn_ptr_substs(&self.parameters);
-                write!(f, "fn(")?;
-                f.write_joined(sig.params(), ", ")?;
-                write!(f, ") -> {}", sig.ret().display(f.db))?;
-            }
-            TypeCtor::FnDef(def) => {
-                let sig = f.db.callable_item_signature(def);
-                let name = match def {
-                    CallableDef::Function(ff) => ff.name(f.db),
-                    CallableDef::Struct(s) => s.name(f.db).unwrap_or_else(Name::missing),
-                    CallableDef::EnumVariant(e) => e.name(f.db).unwrap_or_else(Name::missing),
-                };
-                match def {
-                    CallableDef::Function(_) => write!(f, "fn {}", name)?,
-                    CallableDef::Struct(_) | CallableDef::EnumVariant(_) => write!(f, "{}", name)?,
-                }
-                if self.parameters.len() > 0 {
-                    write!(f, "<")?;
-                    f.write_joined(&*self.parameters.0, ", ")?;
-                    write!(f, ">")?;
-                }
-                write!(f, "(")?;
-                f.write_joined(sig.params(), ", ")?;
-                write!(f, ") -> {}", sig.ret().display(f.db))?;
-            }
-            TypeCtor::Adt(def_id) => {
-                let name = match def_id {
-                    Adt::Struct(s) => s.name(f.db),
-                    Adt::Union(u) => u.name(f.db),
-                    Adt::Enum(e) => e.name(f.db),
-                }
-                .unwrap_or_else(Name::missing);
-                write!(f, "{}", name)?;
-                if self.parameters.len() > 0 {
-                    write!(f, "<")?;
-                    f.write_joined(&*self.parameters.0, ", ")?;
-                    write!(f, ">")?;
-                }
-            }
-            TypeCtor::AssociatedType(type_alias) => {
-                let trait_name = type_alias
-                    .parent_trait(f.db)
-                    .and_then(|t| t.name(f.db))
-                    .unwrap_or_else(Name::missing);
-                let name = type_alias.name(f.db);
-                write!(f, "{}::{}", trait_name, name)?;
-                if self.parameters.len() > 0 {
-                    write!(f, "<")?;
-                    f.write_joined(&*self.parameters.0, ", ")?;
-                    write!(f, ">")?;
-                }
-            }
-            TypeCtor::Closure { .. } => {
-                let sig = self.parameters[0]
-                    .callable_sig(f.db)
-                    .expect("first closure parameter should contain signature");
-                write!(f, "|")?;
-                f.write_joined(sig.params(), ", ")?;
-                write!(f, "| -> {}", sig.ret().display(f.db))?;
-            }
-        }
-        Ok(())
-    }
-}
-
-impl HirDisplay for ProjectionTy {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        if f.should_truncate() {
-            return write!(f, "…");
-        }
-
-        let trait_name = self
-            .associated_ty
-            .parent_trait(f.db)
-            .and_then(|t| t.name(f.db))
-            .unwrap_or_else(Name::missing);
-        write!(f, "<{} as {}", self.parameters[0].display(f.db), trait_name,)?;
-        if self.parameters.len() > 1 {
-            write!(f, "<")?;
-            f.write_joined(&self.parameters[1..], ", ")?;
-            write!(f, ">")?;
-        }
-        write!(f, ">::{}", self.associated_ty.name(f.db))?;
-        Ok(())
-    }
-}
-
-impl HirDisplay for Ty {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        if f.should_truncate() {
-            return write!(f, "…");
-        }
-
-        match self {
-            Ty::Apply(a_ty) => a_ty.hir_fmt(f)?,
-            Ty::Projection(p_ty) => p_ty.hir_fmt(f)?,
-            Ty::Param { name, .. } => write!(f, "{}", name)?,
-            Ty::Bound(idx) => write!(f, "?{}", idx)?,
-            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
-                match self {
-                    Ty::Dyn(_) => write!(f, "dyn ")?,
-                    Ty::Opaque(_) => write!(f, "impl ")?,
-                    _ => unreachable!(),
-                };
-                // Note: This code is written to produce nice results (i.e.
-                // corresponding to surface Rust) for types that can occur in
-                // actual Rust. It will have weird results if the predicates
-                // aren't as expected (i.e. self types = $0, projection
-                // predicates for a certain trait come after the Implemented
-                // predicate for that trait).
-                let mut first = true;
-                let mut angle_open = false;
-                for p in predicates.iter() {
-                    match p {
-                        GenericPredicate::Implemented(trait_ref) => {
-                            if angle_open {
-                                write!(f, ">")?;
-                            }
-                            if !first {
-                                write!(f, " + ")?;
-                            }
-                            // We assume that the self type is $0 (i.e. the
-                            // existential) here, which is the only thing that's
-                            // possible in actual Rust, and hence don't print it
-                            write!(
-                                f,
-                                "{}",
-                                trait_ref.trait_.name(f.db).unwrap_or_else(Name::missing)
-                            )?;
-                            if trait_ref.substs.len() > 1 {
-                                write!(f, "<")?;
-                                f.write_joined(&trait_ref.substs[1..], ", ")?;
-                                // there might be assoc type bindings, so we leave the angle brackets open
-                                angle_open = true;
-                            }
-                        }
-                        GenericPredicate::Projection(projection_pred) => {
-                            // in types in actual Rust, these will always come
-                            // after the corresponding Implemented predicate
-                            if angle_open {
-                                write!(f, ", ")?;
-                            } else {
-                                write!(f, "<")?;
-                                angle_open = true;
-                            }
-                            let name = projection_pred.projection_ty.associated_ty.name(f.db);
-                            write!(f, "{} = ", name)?;
-                            projection_pred.ty.hir_fmt(f)?;
-                        }
-                        GenericPredicate::Error => {
-                            if angle_open {
-                                // impl Trait<X, {error}>
-                                write!(f, ", ")?;
-                            } else if !first {
-                                // impl Trait + {error}
-                                write!(f, " + ")?;
-                            }
-                            p.hir_fmt(f)?;
-                        }
-                    }
-                    first = false;
-                }
-                if angle_open {
-                    write!(f, ">")?;
-                }
-            }
-            Ty::Unknown => write!(f, "{{unknown}}")?,
-            Ty::Infer(..) => write!(f, "_")?,
-        }
-        Ok(())
-    }
-}
-
-impl TraitRef {
-    fn hir_fmt_ext(&self, f: &mut HirFormatter<impl HirDatabase>, use_as: bool) -> fmt::Result {
-        if f.should_truncate() {
-            return write!(f, "…");
-        }
-
-        self.substs[0].hir_fmt(f)?;
-        if use_as {
-            write!(f, " as ")?;
-        } else {
-            write!(f, ": ")?;
-        }
-        write!(f, "{}", self.trait_.name(f.db).unwrap_or_else(Name::missing))?;
-        if self.substs.len() > 1 {
-            write!(f, "<")?;
-            f.write_joined(&self.substs[1..], ", ")?;
-            write!(f, ">")?;
-        }
-        Ok(())
-    }
-}
-
-impl HirDisplay for TraitRef {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        self.hir_fmt_ext(f, false)
-    }
-}
-
-impl HirDisplay for &GenericPredicate {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        HirDisplay::hir_fmt(*self, f)
-    }
-}
-
-impl HirDisplay for GenericPredicate {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        if f.should_truncate() {
-            return write!(f, "…");
-        }
-
-        match self {
-            GenericPredicate::Implemented(trait_ref) => trait_ref.hir_fmt(f)?,
-            GenericPredicate::Projection(projection_pred) => {
-                write!(f, "<")?;
-                projection_pred.projection_ty.trait_ref(f.db).hir_fmt_ext(f, true)?;
-                write!(
-                    f,
-                    ">::{} = {}",
-                    projection_pred.projection_ty.associated_ty.name(f.db),
-                    projection_pred.ty.display(f.db)
-                )?;
-            }
-            GenericPredicate::Error => write!(f, "{{error}}")?,
-        }
-        Ok(())
-    }
-}
-
-impl HirDisplay for Obligation {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        match self {
-            Obligation::Trait(tr) => write!(f, "Implements({})", tr.display(f.db)),
-            Obligation::Projection(proj) => write!(
-                f,
-                "Normalize({} => {})",
-                proj.projection_ty.display(f.db),
-                proj.ty.display(f.db)
-            ),
-        }
-    }
-}
+pub use hir_ty::*;
diff --git a/crates/ra_hir/src/util.rs b/crates/ra_hir/src/util.rs
deleted file mode 100644
index 0095ee45d..000000000
--- a/crates/ra_hir/src/util.rs
+++ /dev/null
@@ -1,12 +0,0 @@
-//! Internal utility functions.
-
-use std::sync::Arc;
-
-/// Helper for mutating `Arc<[T]>` (i.e. `Arc::make_mut` for Arc slices).
-/// The underlying values are cloned if there are other strong references.
-pub(crate) fn make_mut_slice<T: Clone>(a: &mut Arc<[T]>) -> &mut [T] {
-    if Arc::get_mut(a).is_none() {
-        *a = a.iter().cloned().collect();
-    }
-    Arc::get_mut(a).unwrap()
-}
diff --git a/crates/ra_hir_def/src/adt.rs b/crates/ra_hir_def/src/adt.rs
index c9f30923e..3666529b0 100644
--- a/crates/ra_hir_def/src/adt.rs
+++ b/crates/ra_hir_def/src/adt.rs
@@ -12,25 +12,25 @@ use ra_syntax::ast::{self, NameOwner, TypeAscriptionOwner};
 
 use crate::{
     db::DefDatabase, trace::Trace, type_ref::TypeRef, AstItemDef, EnumId, HasChildSource,
-    LocalEnumVariantId, LocalStructFieldId, StructOrUnionId, VariantId,
+    LocalEnumVariantId, LocalStructFieldId, StructId, UnionId, VariantId,
 };
 
 /// Note that we use `StructData` for unions as well!
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct StructData {
-    pub name: Option<Name>,
+    pub name: Name,
     pub variant_data: Arc<VariantData>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct EnumData {
-    pub name: Option<Name>,
+    pub name: Name,
     pub variants: Arena<LocalEnumVariantId, EnumVariantData>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct EnumVariantData {
-    pub name: Option<Name>,
+    pub name: Name,
     pub variant_data: Arc<VariantData>,
 }
 
@@ -49,26 +49,38 @@ pub struct StructFieldData {
 }
 
 impl StructData {
-    pub(crate) fn struct_data_query(db: &impl DefDatabase, id: StructOrUnionId) -> Arc<StructData> {
+    pub(crate) fn struct_data_query(db: &impl DefDatabase, id: StructId) -> Arc<StructData> {
         let src = id.source(db);
-        let name = src.value.name().map(|n| n.as_name());
+        let name = src.value.name().map_or_else(Name::missing, |n| n.as_name());
         let variant_data = VariantData::new(src.value.kind());
         let variant_data = Arc::new(variant_data);
         Arc::new(StructData { name, variant_data })
     }
+    pub(crate) fn union_data_query(db: &impl DefDatabase, id: UnionId) -> Arc<StructData> {
+        let src = id.source(db);
+        let name = src.value.name().map_or_else(Name::missing, |n| n.as_name());
+        let variant_data = VariantData::new(
+            src.value
+                .record_field_def_list()
+                .map(ast::StructKind::Record)
+                .unwrap_or(ast::StructKind::Unit),
+        );
+        let variant_data = Arc::new(variant_data);
+        Arc::new(StructData { name, variant_data })
+    }
 }
 
 impl EnumData {
     pub(crate) fn enum_data_query(db: &impl DefDatabase, e: EnumId) -> Arc<EnumData> {
         let src = e.source(db);
-        let name = src.value.name().map(|n| n.as_name());
+        let name = src.value.name().map_or_else(Name::missing, |n| n.as_name());
         let mut trace = Trace::new_for_arena();
         lower_enum(&mut trace, &src.value);
         Arc::new(EnumData { name, variants: trace.into_arena() })
     }
 
-    pub(crate) fn variant(&self, name: &Name) -> Option<LocalEnumVariantId> {
-        let (id, _) = self.variants.iter().find(|(_id, data)| data.name.as_ref() == Some(name))?;
+    pub fn variant(&self, name: &Name) -> Option<LocalEnumVariantId> {
+        let (id, _) = self.variants.iter().find(|(_id, data)| &data.name == name)?;
         Some(id)
     }
 }
@@ -92,7 +104,7 @@ fn lower_enum(
         trace.alloc(
             || var.clone(),
             || EnumVariantData {
-                name: var.name().map(|it| it.as_name()),
+                name: var.name().map_or_else(Name::missing, |it| it.as_name()),
                 variant_data: Arc::new(VariantData::new(var.kind())),
             },
         );
@@ -117,6 +129,10 @@ impl VariantData {
         }
     }
 
+    pub fn field(&self, name: &Name) -> Option<LocalStructFieldId> {
+        self.fields().iter().find_map(|(id, data)| if &data.name == name { Some(id) } else { None })
+    }
+
     pub fn is_unit(&self) -> bool {
         match self {
             VariantData::Unit => true,
@@ -137,7 +153,12 @@ impl HasChildSource for VariantId {
                 let src = it.parent.child_source(db);
                 src.map(|map| map[it.local_id].kind())
             }
-            VariantId::StructId(it) => it.0.source(db).map(|it| it.kind()),
+            VariantId::StructId(it) => it.source(db).map(|it| it.kind()),
+            VariantId::UnionId(it) => it.source(db).map(|it| {
+                it.record_field_def_list()
+                    .map(ast::StructKind::Record)
+                    .unwrap_or(ast::StructKind::Unit)
+            }),
         };
         let mut trace = Trace::new_for_map();
         lower_struct(&mut trace, &src.value);
diff --git a/crates/ra_hir_def/src/attr.rs b/crates/ra_hir_def/src/attr.rs
index 53456fc08..fffb22201 100644
--- a/crates/ra_hir_def/src/attr.rs
+++ b/crates/ra_hir_def/src/attr.rs
@@ -35,7 +35,7 @@ impl Attrs {
         match def {
             AttrDefId::ModuleId(module) => {
                 let def_map = db.crate_def_map(module.krate);
-                let src = match def_map[module.module_id].declaration_source(db) {
+                let src = match def_map[module.local_id].declaration_source(db) {
                     Some(it) => it,
                     None => return Attrs::default(),
                 };
@@ -54,9 +54,9 @@ impl Attrs {
                 Attrs::from_attrs_owner(db, src.map(|it| it as &dyn AttrsOwner))
             }
             AttrDefId::AdtId(it) => match it {
-                AdtId::StructId(it) => attrs_from_ast(it.0.lookup_intern(db).ast_id, db),
+                AdtId::StructId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
                 AdtId::EnumId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
-                AdtId::UnionId(it) => attrs_from_ast(it.0.lookup_intern(db).ast_id, db),
+                AdtId::UnionId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
             },
             AttrDefId::TraitId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
             AttrDefId::MacroDefId(it) => attrs_from_ast(it.ast_id, db),
diff --git a/crates/ra_hir_def/src/body.rs b/crates/ra_hir_def/src/body.rs
index d77ccb272..a57a0176d 100644
--- a/crates/ra_hir_def/src/body.rs
+++ b/crates/ra_hir_def/src/body.rs
@@ -6,8 +6,7 @@ pub mod scope;
 use std::{ops::Index, sync::Arc};
 
 use hir_expand::{
-    either::Either, hygiene::Hygiene, AstId, HirFileId, MacroCallLoc, MacroDefId, MacroFileKind,
-    Source,
+    either::Either, hygiene::Hygiene, AstId, HirFileId, MacroDefId, MacroFileKind, Source,
 };
 use ra_arena::{map::ArenaMap, Arena};
 use ra_syntax::{ast, AstNode, AstPtr};
@@ -47,7 +46,7 @@ impl Expander {
 
         if let Some(path) = macro_call.path().and_then(|path| self.parse_path(path)) {
             if let Some(def) = self.resolve_path_as_macro(db, &path) {
-                let call_id = db.intern_macro(MacroCallLoc { def, ast_id });
+                let call_id = def.as_call_id(db, ast_id);
                 let file_id = call_id.as_file(MacroFileKind::Expr);
                 if let Some(node) = db.parse_or_expand(file_id) {
                     if let Some(expr) = ast::Expr::cast(node) {
@@ -83,7 +82,7 @@ impl Expander {
     }
 
     fn resolve_path_as_macro(&self, db: &impl DefDatabase, path: &Path) -> Option<MacroDefId> {
-        self.crate_def_map.resolve_path(db, self.module.module_id, path).0.take_macros()
+        self.crate_def_map.resolve_path(db, self.module.local_id, path).0.take_macros()
     }
 }
 
diff --git a/crates/ra_hir_def/src/data.rs b/crates/ra_hir_def/src/data.rs
index 68bea34df..fee10b237 100644
--- a/crates/ra_hir_def/src/data.rs
+++ b/crates/ra_hir_def/src/data.rs
@@ -86,39 +86,53 @@ impl TypeAliasData {
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct TraitData {
-    pub name: Option<Name>,
-    pub items: Vec<AssocItemId>,
+    pub name: Name,
+    pub items: Vec<(Name, AssocItemId)>,
     pub auto: bool,
 }
 
 impl TraitData {
     pub(crate) fn trait_data_query(db: &impl DefDatabase, tr: TraitId) -> Arc<TraitData> {
         let src = tr.source(db);
-        let name = src.value.name().map(|n| n.as_name());
+        let name = src.value.name().map_or_else(Name::missing, |n| n.as_name());
         let auto = src.value.is_auto();
         let ast_id_map = db.ast_id_map(src.file_id);
+
+        let container = ContainerId::TraitId(tr);
         let items = if let Some(item_list) = src.value.item_list() {
             item_list
                 .impl_items()
                 .map(|item_node| match item_node {
-                    ast::ImplItem::FnDef(it) => FunctionLoc {
-                        container: ContainerId::TraitId(tr),
-                        ast_id: AstId::new(src.file_id, ast_id_map.ast_id(&it)),
+                    ast::ImplItem::FnDef(it) => {
+                        let name = it.name().map_or_else(Name::missing, |it| it.as_name());
+                        let def = FunctionLoc {
+                            container,
+                            ast_id: AstId::new(src.file_id, ast_id_map.ast_id(&it)),
+                        }
+                        .intern(db)
+                        .into();
+                        (name, def)
                     }
-                    .intern(db)
-                    .into(),
-                    ast::ImplItem::ConstDef(it) => ConstLoc {
-                        container: ContainerId::TraitId(tr),
-                        ast_id: AstId::new(src.file_id, ast_id_map.ast_id(&it)),
+                    ast::ImplItem::ConstDef(it) => {
+                        let name = it.name().map_or_else(Name::missing, |it| it.as_name());
+                        let def = ConstLoc {
+                            container,
+                            ast_id: AstId::new(src.file_id, ast_id_map.ast_id(&it)),
+                        }
+                        .intern(db)
+                        .into();
+                        (name, def)
                     }
-                    .intern(db)
-                    .into(),
-                    ast::ImplItem::TypeAliasDef(it) => TypeAliasLoc {
-                        container: ContainerId::TraitId(tr),
-                        ast_id: AstId::new(src.file_id, ast_id_map.ast_id(&it)),
+                    ast::ImplItem::TypeAliasDef(it) => {
+                        let name = it.name().map_or_else(Name::missing, |it| it.as_name());
+                        let def = TypeAliasLoc {
+                            container,
+                            ast_id: AstId::new(src.file_id, ast_id_map.ast_id(&it)),
+                        }
+                        .intern(db)
+                        .into();
+                        (name, def)
                     }
-                    .intern(db)
-                    .into(),
                 })
                 .collect()
         } else {
@@ -128,11 +142,18 @@ impl TraitData {
     }
 
     pub fn associated_types(&self) -> impl Iterator<Item = TypeAliasId> + '_ {
-        self.items.iter().filter_map(|item| match item {
+        self.items.iter().filter_map(|(_name, item)| match item {
             AssocItemId::TypeAliasId(t) => Some(*t),
             _ => None,
         })
     }
+
+    pub fn associated_type_by_name(&self, name: &Name) -> Option<TypeAliasId> {
+        self.items.iter().find_map(|(item_name, item)| match item {
+            AssocItemId::TypeAliasId(t) if item_name == name => Some(*t),
+            _ => None,
+        })
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -193,6 +214,7 @@ impl ImplData {
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ConstData {
+    /// const _: () = ();
     pub name: Option<Name>,
     pub type_ref: TypeRef,
 }
diff --git a/crates/ra_hir_def/src/db.rs b/crates/ra_hir_def/src/db.rs
index 32adb11bd..ef5611ffc 100644
--- a/crates/ra_hir_def/src/db.rs
+++ b/crates/ra_hir_def/src/db.rs
@@ -18,8 +18,8 @@ use crate::{
         CrateDefMap,
     },
     AttrDefId, ConstId, ConstLoc, DefWithBodyId, EnumId, FunctionId, FunctionLoc, GenericDefId,
-    ImplId, ItemLoc, ModuleId, StaticId, StaticLoc, StructOrUnionId, TraitId, TypeAliasId,
-    TypeAliasLoc,
+    ImplId, ItemLoc, ModuleId, StaticId, StaticLoc, StructId, TraitId, TypeAliasId, TypeAliasLoc,
+    UnionId,
 };
 
 #[salsa::query_group(InternDatabaseStorage)]
@@ -27,7 +27,9 @@ pub trait InternDatabase: SourceDatabase {
     #[salsa::interned]
     fn intern_function(&self, loc: FunctionLoc) -> FunctionId;
     #[salsa::interned]
-    fn intern_struct_or_union(&self, loc: ItemLoc<ast::StructDef>) -> StructOrUnionId;
+    fn intern_struct(&self, loc: ItemLoc<ast::StructDef>) -> StructId;
+    #[salsa::interned]
+    fn intern_union(&self, loc: ItemLoc<ast::UnionDef>) -> UnionId;
     #[salsa::interned]
     fn intern_enum(&self, loc: ItemLoc<ast::EnumDef>) -> EnumId;
     #[salsa::interned]
@@ -57,7 +59,9 @@ pub trait DefDatabase: InternDatabase + AstDatabase {
     fn crate_def_map(&self, krate: CrateId) -> Arc<CrateDefMap>;
 
     #[salsa::invoke(StructData::struct_data_query)]
-    fn struct_data(&self, id: StructOrUnionId) -> Arc<StructData>;
+    fn struct_data(&self, id: StructId) -> Arc<StructData>;
+    #[salsa::invoke(StructData::union_data_query)]
+    fn union_data(&self, id: UnionId) -> Arc<StructData>;
 
     #[salsa::invoke(EnumData::enum_data_query)]
     fn enum_data(&self, e: EnumId) -> Arc<EnumData>;
diff --git a/crates/ra_hir_def/src/docs.rs b/crates/ra_hir_def/src/docs.rs
index 90a8627bc..34ed9b7a5 100644
--- a/crates/ra_hir_def/src/docs.rs
+++ b/crates/ra_hir_def/src/docs.rs
@@ -36,7 +36,7 @@ impl Documentation {
         match def {
             AttrDefId::ModuleId(module) => {
                 let def_map = db.crate_def_map(module.krate);
-                let src = def_map[module.module_id].declaration_source(db)?;
+                let src = def_map[module.local_id].declaration_source(db)?;
                 docs_from_ast(&src.value)
             }
             AttrDefId::StructFieldId(it) => {
@@ -47,9 +47,9 @@ impl Documentation {
                 }
             }
             AttrDefId::AdtId(it) => match it {
-                AdtId::StructId(it) => docs_from_ast(&it.0.source(db).value),
+                AdtId::StructId(it) => docs_from_ast(&it.source(db).value),
                 AdtId::EnumId(it) => docs_from_ast(&it.source(db).value),
-                AdtId::UnionId(it) => docs_from_ast(&it.0.source(db).value),
+                AdtId::UnionId(it) => docs_from_ast(&it.source(db).value),
             },
             AttrDefId::EnumVariantId(it) => {
                 let src = it.parent.child_source(db);
diff --git a/crates/ra_hir_def/src/generics.rs b/crates/ra_hir_def/src/generics.rs
index 015fe772e..3f94e40e4 100644
--- a/crates/ra_hir_def/src/generics.rs
+++ b/crates/ra_hir_def/src/generics.rs
@@ -60,10 +60,8 @@ impl GenericParams {
         // FIXME: add `: Sized` bound for everything except for `Self` in traits
         match def {
             GenericDefId::FunctionId(it) => generics.fill(&it.lookup(db).source(db).value, start),
-            GenericDefId::AdtId(AdtId::StructId(it)) => {
-                generics.fill(&it.0.source(db).value, start)
-            }
-            GenericDefId::AdtId(AdtId::UnionId(it)) => generics.fill(&it.0.source(db).value, start),
+            GenericDefId::AdtId(AdtId::StructId(it)) => generics.fill(&it.source(db).value, start),
+            GenericDefId::AdtId(AdtId::UnionId(it)) => generics.fill(&it.source(db).value, start),
             GenericDefId::AdtId(AdtId::EnumId(it)) => generics.fill(&it.source(db).value, start),
             GenericDefId::TraitId(it) => {
                 // traits get the Self type as an implicit first type parameter
diff --git a/crates/ra_hir_def/src/lang_item.rs b/crates/ra_hir_def/src/lang_item.rs
index f15c23db9..f4fdbdcfc 100644
--- a/crates/ra_hir_def/src/lang_item.rs
+++ b/crates/ra_hir_def/src/lang_item.rs
@@ -41,7 +41,7 @@ impl LangItems {
         crate_def_map
             .modules
             .iter()
-            .filter_map(|(module_id, _)| db.module_lang_items(ModuleId { krate, module_id }))
+            .filter_map(|(local_id, _)| db.module_lang_items(ModuleId { krate, local_id }))
             .for_each(|it| lang_items.items.extend(it.items.iter().map(|(k, v)| (k.clone(), *v))));
 
         Arc::new(lang_items)
@@ -80,7 +80,7 @@ impl LangItems {
     fn collect_lang_items(&mut self, db: &impl DefDatabase, module: ModuleId) {
         // Look for impl targets
         let def_map = db.crate_def_map(module.krate);
-        let module_data = &def_map[module.module_id];
+        let module_data = &def_map[module.local_id];
         for &impl_block in module_data.impls.iter() {
             self.collect_lang_item(db, impl_block, LangItemTarget::ImplBlockId)
         }
diff --git a/crates/ra_hir_def/src/lib.rs b/crates/ra_hir_def/src/lib.rs
index 8e8c2d749..bc5530896 100644
--- a/crates/ra_hir_def/src/lib.rs
+++ b/crates/ra_hir_def/src/lib.rs
@@ -27,7 +27,7 @@ pub mod body;
 pub mod resolver;
 
 mod trace;
-mod nameres;
+pub mod nameres;
 
 #[cfg(test)]
 mod test_db;
@@ -50,7 +50,7 @@ impl_arena_id!(LocalImportId);
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ModuleId {
     pub krate: CrateId,
-    pub module_id: LocalModuleId,
+    pub local_id: LocalModuleId,
 }
 
 /// An ID of a module, **local** to a specific crate
@@ -141,30 +141,26 @@ impl Lookup for FunctionId {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct StructOrUnionId(salsa::InternId);
-impl_intern_key!(StructOrUnionId);
-impl AstItemDef<ast::StructDef> for StructOrUnionId {
+pub struct StructId(salsa::InternId);
+impl_intern_key!(StructId);
+impl AstItemDef<ast::StructDef> for StructId {
     fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::StructDef>) -> Self {
-        db.intern_struct_or_union(loc)
+        db.intern_struct(loc)
     }
     fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::StructDef> {
-        db.lookup_intern_struct_or_union(self)
+        db.lookup_intern_struct(self)
     }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct StructId(pub StructOrUnionId);
-impl From<StructId> for StructOrUnionId {
-    fn from(id: StructId) -> StructOrUnionId {
-        id.0
+pub struct UnionId(salsa::InternId);
+impl_intern_key!(UnionId);
+impl AstItemDef<ast::UnionDef> for UnionId {
+    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::UnionDef>) -> Self {
+        db.intern_union(loc)
     }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct UnionId(pub StructOrUnionId);
-impl From<UnionId> for StructOrUnionId {
-    fn from(id: UnionId) -> StructOrUnionId {
-        id.0
+    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::UnionDef> {
+        db.lookup_intern_union(self)
     }
 }
 
@@ -402,6 +398,16 @@ impl_froms!(
     ConstId
 );
 
+impl From<AssocItemId> for GenericDefId {
+    fn from(item: AssocItemId) -> Self {
+        match item {
+            AssocItemId::FunctionId(f) => f.into(),
+            AssocItemId::ConstId(c) => c.into(),
+            AssocItemId::TypeAliasId(t) => t.into(),
+        }
+    }
+}
+
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub enum AttrDefId {
     ModuleId(ModuleId),
@@ -435,6 +441,7 @@ impl_froms!(
 pub enum VariantId {
     EnumVariantId(EnumVariantId),
     StructId(StructId),
+    UnionId(UnionId),
 }
 impl_froms!(VariantId: EnumVariantId, StructId);
 
@@ -485,13 +492,23 @@ impl HasModule for ConstLoc {
 impl HasModule for AdtId {
     fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
         match self {
-            AdtId::StructId(it) => it.0.module(db),
-            AdtId::UnionId(it) => it.0.module(db),
+            AdtId::StructId(it) => it.module(db),
+            AdtId::UnionId(it) => it.module(db),
             AdtId::EnumId(it) => it.module(db),
         }
     }
 }
 
+impl HasModule for DefWithBodyId {
+    fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
+        match self {
+            DefWithBodyId::FunctionId(it) => it.lookup(db).module(db),
+            DefWithBodyId::StaticId(it) => it.lookup(db).module(db),
+            DefWithBodyId::ConstId(it) => it.lookup(db).module(db),
+        }
+    }
+}
+
 impl HasModule for StaticLoc {
     fn module(&self, _db: &impl db::DefDatabase) -> ModuleId {
         self.container
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index 41becf8df..fd8245113 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -6,7 +6,7 @@
 use hir_expand::{
     builtin_macro::find_builtin_macro,
     name::{self, AsName, Name},
-    HirFileId, MacroCallId, MacroCallLoc, MacroDefId, MacroDefKind, MacroFileKind,
+    HirFileId, MacroCallId, MacroDefId, MacroDefKind, MacroFileKind,
 };
 use ra_cfg::CfgOptions;
 use ra_db::{CrateId, FileId};
@@ -25,7 +25,7 @@ use crate::{
     per_ns::PerNs,
     AdtId, AstId, AstItemDef, ConstLoc, ContainerId, EnumId, EnumVariantId, FunctionLoc, ImplId,
     Intern, LocalImportId, LocalModuleId, LocationCtx, ModuleDefId, ModuleId, StaticLoc, StructId,
-    StructOrUnionId, TraitId, TypeAliasLoc, UnionId,
+    TraitId, TypeAliasLoc, UnionId,
 };
 
 pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> CrateDefMap {
@@ -37,7 +37,7 @@ pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> C
         log::debug!("crate dep {:?} -> {:?}", dep.name, dep.crate_id);
         def_map.extern_prelude.insert(
             dep.as_name(),
-            ModuleId { krate: dep.crate_id, module_id: dep_def_map.root }.into(),
+            ModuleId { krate: dep.crate_id, local_id: dep_def_map.root }.into(),
         );
 
         // look for the prelude
@@ -323,7 +323,7 @@ where
                         tested_by!(glob_across_crates);
                         // glob import from other crate => we can just import everything once
                         let item_map = self.db.crate_def_map(m.krate);
-                        let scope = &item_map[m.module_id].scope;
+                        let scope = &item_map[m.local_id].scope;
 
                         // Module scoped macros is included
                         let items = scope
@@ -337,7 +337,7 @@ where
                         // glob import from same crate => we do an initial
                         // import, and then need to propagate any further
                         // additions
-                        let scope = &self.def_map[m.module_id].scope;
+                        let scope = &self.def_map[m.local_id].scope;
 
                         // Module scoped macros is included
                         let items = scope
@@ -349,7 +349,7 @@ where
                         self.update(module_id, Some(import_id), &items);
                         // record the glob import in case we add further items
                         self.glob_imports
-                            .entry(m.module_id)
+                            .entry(m.local_id)
                             .or_default()
                             .push((module_id, import_id));
                     }
@@ -362,7 +362,7 @@ where
                         .variants
                         .iter()
                         .filter_map(|(local_id, variant_data)| {
-                            let name = variant_data.name.clone()?;
+                            let name = variant_data.name.clone();
                             let variant = EnumVariantId { parent: e, local_id };
                             let res = Resolution {
                                 def: PerNs::both(variant.into(), variant.into()),
@@ -480,7 +480,7 @@ where
             );
 
             if let Some(def) = resolved_res.resolved_def.take_macros() {
-                let call_id = self.db.intern_macro(MacroCallLoc { def, ast_id: *ast_id });
+                let call_id = def.as_call_id(self.db, *ast_id);
                 resolved.push((*module_id, call_id, def));
                 res = ReachedFixedPoint::No;
                 return false;
@@ -590,7 +590,7 @@ where
                     raw::RawItemKind::Impl(imp) => {
                         let module = ModuleId {
                             krate: self.def_collector.def_map.krate,
-                            module_id: self.module_id,
+                            local_id: self.module_id,
                         };
                         let ctx = LocationCtx::new(self.def_collector.db, module, self.file_id);
                         let imp_id = ImplId::from_ast_id(ctx, self.raw_items[imp].ast_id);
@@ -673,7 +673,7 @@ where
         modules[self.module_id].children.insert(name.clone(), res);
         let resolution = Resolution {
             def: PerNs::types(
-                ModuleId { krate: self.def_collector.def_map.krate, module_id: res }.into(),
+                ModuleId { krate: self.def_collector.def_map.krate, local_id: res }.into(),
             ),
             import: None,
         };
@@ -682,8 +682,7 @@ where
     }
 
     fn define_def(&mut self, def: &raw::DefData) {
-        let module =
-            ModuleId { krate: self.def_collector.def_map.krate, module_id: self.module_id };
+        let module = ModuleId { krate: self.def_collector.def_map.krate, local_id: self.module_id };
         let ctx = LocationCtx::new(self.def_collector.db, module, self.file_id);
 
         let name = def.name.clone();
@@ -698,14 +697,12 @@ where
                 PerNs::values(def.into())
             }
             raw::DefKind::Struct(ast_id) => {
-                let id = StructOrUnionId::from_ast_id(ctx, ast_id).into();
-                let s = StructId(id).into();
-                PerNs::both(s, s)
+                let id = StructId::from_ast_id(ctx, ast_id).into();
+                PerNs::both(id, id)
             }
             raw::DefKind::Union(ast_id) => {
-                let id = StructOrUnionId::from_ast_id(ctx, ast_id).into();
-                let u = UnionId(id).into();
-                PerNs::both(u, u)
+                let id = UnionId::from_ast_id(ctx, ast_id).into();
+                PerNs::both(id, id)
             }
             raw::DefKind::Enum(ast_id) => PerNs::types(EnumId::from_ast_id(ctx, ast_id).into()),
             raw::DefKind::Const(ast_id) => {
@@ -775,8 +772,7 @@ where
         if let Some(macro_def) = mac.path.as_ident().and_then(|name| {
             self.def_collector.def_map[self.module_id].scope.get_legacy_macro(&name)
         }) {
-            let macro_call_id =
-                self.def_collector.db.intern_macro(MacroCallLoc { def: macro_def, ast_id });
+            let macro_call_id = macro_def.as_call_id(self.def_collector.db, ast_id);
 
             self.def_collector.collect_macro_expansion(self.module_id, macro_call_id, macro_def);
             return;
diff --git a/crates/ra_hir_def/src/nameres/path_resolution.rs b/crates/ra_hir_def/src/nameres/path_resolution.rs
index 9455f22bb..b72c55bd1 100644
--- a/crates/ra_hir_def/src/nameres/path_resolution.rs
+++ b/crates/ra_hir_def/src/nameres/path_resolution.rs
@@ -74,19 +74,19 @@ impl CrateDefMap {
             PathKind::DollarCrate(krate) => {
                 if krate == self.krate {
                     tested_by!(macro_dollar_crate_self);
-                    PerNs::types(ModuleId { krate: self.krate, module_id: self.root }.into())
+                    PerNs::types(ModuleId { krate: self.krate, local_id: self.root }.into())
                 } else {
                     let def_map = db.crate_def_map(krate);
-                    let module = ModuleId { krate, module_id: def_map.root };
+                    let module = ModuleId { krate, local_id: def_map.root };
                     tested_by!(macro_dollar_crate_other);
                     PerNs::types(module.into())
                 }
             }
             PathKind::Crate => {
-                PerNs::types(ModuleId { krate: self.krate, module_id: self.root }.into())
+                PerNs::types(ModuleId { krate: self.krate, local_id: self.root }.into())
             }
             PathKind::Self_ => {
-                PerNs::types(ModuleId { krate: self.krate, module_id: original_module }.into())
+                PerNs::types(ModuleId { krate: self.krate, local_id: original_module }.into())
             }
             // plain import or absolute path in 2015: crate-relative with
             // fallback to extern prelude (with the simplification in
@@ -113,7 +113,7 @@ impl CrateDefMap {
             }
             PathKind::Super => {
                 if let Some(p) = self.modules[original_module].parent {
-                    PerNs::types(ModuleId { krate: self.krate, module_id: p }.into())
+                    PerNs::types(ModuleId { krate: self.krate, local_id: p }.into())
                 } else {
                     log::debug!("super path in root module");
                     return ResolvePathResult::empty(ReachedFixedPoint::Yes);
@@ -160,7 +160,7 @@ impl CrateDefMap {
                             Path { segments: path.segments[i..].to_vec(), kind: PathKind::Self_ };
                         log::debug!("resolving {:?} in other crate", path);
                         let defp_map = db.crate_def_map(module.krate);
-                        let (def, s) = defp_map.resolve_path(db, module.module_id, &path);
+                        let (def, s) = defp_map.resolve_path(db, module.local_id, &path);
                         return ResolvePathResult::with(
                             def,
                             ReachedFixedPoint::Yes,
@@ -169,7 +169,7 @@ impl CrateDefMap {
                     }
 
                     // Since it is a qualified path here, it should not contains legacy macros
-                    match self[module.module_id].scope.get(&segment.name) {
+                    match self[module.local_id].scope.get(&segment.name) {
                         Some(res) => res.def,
                         _ => {
                             log::debug!("path segment {:?} not found", segment.name);
@@ -254,7 +254,7 @@ impl CrateDefMap {
                 keep = db.crate_def_map(prelude.krate);
                 &keep
             };
-            def_map[prelude.module_id].scope.get(name).map_or_else(PerNs::none, |res| res.def)
+            def_map[prelude.local_id].scope.get(name).map_or_else(PerNs::none, |res| res.def)
         } else {
             PerNs::none()
         }
diff --git a/crates/ra_hir_def/src/nameres/raw.rs b/crates/ra_hir_def/src/nameres/raw.rs
index 401af031c..6eb106094 100644
--- a/crates/ra_hir_def/src/nameres/raw.rs
+++ b/crates/ra_hir_def/src/nameres/raw.rs
@@ -176,7 +176,7 @@ pub(super) struct DefData {
 pub(super) enum DefKind {
     Function(FileAstId<ast::FnDef>),
     Struct(FileAstId<ast::StructDef>),
-    Union(FileAstId<ast::StructDef>),
+    Union(FileAstId<ast::UnionDef>),
     Enum(FileAstId<ast::EnumDef>),
     Const(FileAstId<ast::ConstDef>),
     Static(FileAstId<ast::StaticDef>),
@@ -246,11 +246,12 @@ impl RawItemsCollector {
             ast::ModuleItem::StructDef(it) => {
                 let id = self.source_ast_id_map.ast_id(&it);
                 let name = it.name();
-                if it.is_union() {
-                    (DefKind::Union(id), name)
-                } else {
-                    (DefKind::Struct(id), name)
-                }
+                (DefKind::Struct(id), name)
+            }
+            ast::ModuleItem::UnionDef(it) => {
+                let id = self.source_ast_id_map.ast_id(&it);
+                let name = it.name();
+                (DefKind::Union(id), name)
             }
             ast::ModuleItem::EnumDef(it) => {
                 (DefKind::Enum(self.source_ast_id_map.ast_id(&it)), it.name())
diff --git a/crates/ra_hir_def/src/nameres/tests.rs b/crates/ra_hir_def/src/nameres/tests.rs
index f502f1cb3..87fcd617c 100644
--- a/crates/ra_hir_def/src/nameres/tests.rs
+++ b/crates/ra_hir_def/src/nameres/tests.rs
@@ -82,6 +82,12 @@ fn crate_def_map_smoke_test() {
 
         //- /foo/bar.rs
         pub struct Baz;
+
+        union U {
+            to_be: bool,
+            not_to_be: u8,
+        }
+
         enum E { V }
         ",
     );
@@ -99,6 +105,7 @@ fn crate_def_map_smoke_test() {
         ⋮crate::foo::bar
         ⋮Baz: t v
         ⋮E: t
+        ⋮U: t v
     "###)
 }
 
diff --git a/crates/ra_hir_def/src/path.rs b/crates/ra_hir_def/src/path.rs
index 0e606fd0e..6810a26db 100644
--- a/crates/ra_hir_def/src/path.rs
+++ b/crates/ra_hir_def/src/path.rs
@@ -97,7 +97,7 @@ impl Path {
 
     /// Converts an `ast::Path` to `Path`. Works with use trees.
     /// It correctly handles `$crate` based path from macro call.
-    pub(crate) fn from_src(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path> {
+    pub fn from_src(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path> {
         let mut kind = PathKind::Plain;
         let mut segments = Vec::new();
         loop {
diff --git a/crates/ra_hir_def/src/resolver.rs b/crates/ra_hir_def/src/resolver.rs
index 95b3c926d..0847f6dcf 100644
--- a/crates/ra_hir_def/src/resolver.rs
+++ b/crates/ra_hir_def/src/resolver.rs
@@ -61,6 +61,8 @@ pub enum TypeNs {
     GenericParam(u32),
     AdtId(AdtId),
     AdtSelfType(AdtId),
+    // Yup, enum variants are added to the types ns, but any usage of variant as
+    // type is an error.
     EnumVariantId(EnumVariantId),
     TypeAliasId(TypeAliasId),
     BuiltinType(BuiltinType),
@@ -323,7 +325,7 @@ impl Resolver {
             if let Scope::ModuleScope(m) = scope {
                 if let Some(prelude) = m.crate_def_map.prelude {
                     let prelude_def_map = db.crate_def_map(prelude.krate);
-                    traits.extend(prelude_def_map[prelude.module_id].scope.traits());
+                    traits.extend(prelude_def_map[prelude.local_id].scope.traits());
                 }
                 traits.extend(m.crate_def_map[m.module_id].scope.traits());
             }
@@ -400,7 +402,7 @@ impl Scope {
                 });
                 if let Some(prelude) = m.crate_def_map.prelude {
                     let prelude_def_map = db.crate_def_map(prelude.krate);
-                    prelude_def_map[prelude.module_id].scope.entries().for_each(|(name, res)| {
+                    prelude_def_map[prelude.local_id].scope.entries().for_each(|(name, res)| {
                         f(name.clone(), ScopeDef::PerNs(res.def));
                     });
                 }
@@ -482,7 +484,7 @@ impl Resolver {
     }
 }
 
-pub trait HasResolver {
+pub trait HasResolver: Copy {
     /// Builds a resolver for type references inside this def.
     fn resolver(self, db: &impl DefDatabase) -> Resolver;
 }
@@ -490,7 +492,7 @@ pub trait HasResolver {
 impl HasResolver for ModuleId {
     fn resolver(self, db: &impl DefDatabase) -> Resolver {
         let def_map = db.crate_def_map(self.krate);
-        Resolver::default().push_module_scope(def_map, self.module_id)
+        Resolver::default().push_module_scope(def_map, self.local_id)
     }
 }
 
@@ -500,7 +502,7 @@ impl HasResolver for TraitId {
     }
 }
 
-impl<T: Into<AdtId>> HasResolver for T {
+impl<T: Into<AdtId> + Copy> HasResolver for T {
     fn resolver(self, db: &impl DefDatabase) -> Resolver {
         let def = self.into();
         def.module(db)
diff --git a/crates/ra_hir_def/src/test_db.rs b/crates/ra_hir_def/src/test_db.rs
index 439e8a412..54e3a84bd 100644
--- a/crates/ra_hir_def/src/test_db.rs
+++ b/crates/ra_hir_def/src/test_db.rs
@@ -24,7 +24,9 @@ impl salsa::Database for TestDB {
     fn salsa_runtime(&self) -> &salsa::Runtime<Self> {
         &self.runtime
     }
-
+    fn salsa_runtime_mut(&mut self) -> &mut salsa::Runtime<Self> {
+        &mut self.runtime
+    }
     fn salsa_event(&self, event: impl Fn() -> salsa::Event<TestDB>) {
         let mut events = self.events.lock().unwrap();
         if let Some(events) = &mut *events {
diff --git a/crates/ra_hir_expand/src/lib.rs b/crates/ra_hir_expand/src/lib.rs
index 4f3ccf1d0..b6a739cda 100644
--- a/crates/ra_hir_expand/src/lib.rs
+++ b/crates/ra_hir_expand/src/lib.rs
@@ -135,6 +135,16 @@ pub struct MacroDefId {
     pub kind: MacroDefKind,
 }
 
+impl MacroDefId {
+    pub fn as_call_id(
+        self,
+        db: &dyn db::AstDatabase,
+        ast_id: AstId<ast::MacroCall>,
+    ) -> MacroCallId {
+        db.intern_macro(MacroCallLoc { def: self, ast_id })
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum MacroDefKind {
     Declarative,
@@ -143,8 +153,8 @@ pub enum MacroDefKind {
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct MacroCallLoc {
-    pub def: MacroDefId,
-    pub ast_id: AstId<ast::MacroCall>,
+    pub(crate) def: MacroDefId,
+    pub(crate) ast_id: AstId<ast::MacroCall>,
 }
 
 impl MacroCallId {
diff --git a/crates/ra_hir_expand/src/test_db.rs b/crates/ra_hir_expand/src/test_db.rs
index d23e75d9e..918736e2a 100644
--- a/crates/ra_hir_expand/src/test_db.rs
+++ b/crates/ra_hir_expand/src/test_db.rs
@@ -23,6 +23,10 @@ impl salsa::Database for TestDB {
         &self.runtime
     }
 
+    fn salsa_runtime_mut(&mut self) -> &mut salsa::Runtime<Self> {
+        &mut self.runtime
+    }
+
     fn salsa_event(&self, event: impl Fn() -> salsa::Event<TestDB>) {
         let mut events = self.events.lock().unwrap();
         if let Some(events) = &mut *events {
diff --git a/crates/ra_hir_ty/Cargo.toml b/crates/ra_hir_ty/Cargo.toml
new file mode 100644
index 000000000..429242870
--- /dev/null
+++ b/crates/ra_hir_ty/Cargo.toml
@@ -0,0 +1,32 @@
+[package]
+edition = "2018"
+name = "ra_hir_ty"
+version = "0.1.0"
+authors = ["rust-analyzer developers"]
+
+[lib]
+doctest = false
+
+[dependencies]
+arrayvec = "0.5.1"
+ena = "0.13"
+log = "0.4.5"
+rustc-hash = "1.0"
+
+hir_def = { path = "../ra_hir_def", package = "ra_hir_def" }
+hir_expand = { path = "../ra_hir_expand", package = "ra_hir_expand" }
+ra_arena = { path = "../ra_arena" }
+ra_db = { path = "../ra_db" }
+ra_prof = { path = "../ra_prof" }
+ra_syntax = { path = "../ra_syntax" }
+test_utils = { path = "../test_utils" }
+
+# https://github.com/rust-lang/chalk/pull/294
+chalk-solve =   { git = "https://github.com/jackh726/chalk.git", rev = "095cd38a4f16337913bba487f2055b9ca0179f30" }
+chalk-rust-ir = { git = "https://github.com/jackh726/chalk.git", rev = "095cd38a4f16337913bba487f2055b9ca0179f30" }
+chalk-ir =      { git = "https://github.com/jackh726/chalk.git", rev = "095cd38a4f16337913bba487f2055b9ca0179f30" }
+
+lalrpop-intern = "0.15.1"
+
+[dev-dependencies]
+insta = "0.12.0"
diff --git a/crates/ra_hir/src/ty/autoderef.rs b/crates/ra_hir_ty/src/autoderef.rs
index 41c99d227..9d1d4e48c 100644
--- a/crates/ra_hir/src/ty/autoderef.rs
+++ b/crates/ra_hir_ty/src/autoderef.rs
@@ -5,49 +5,56 @@
 
 use std::iter::successors;
 
-use hir_def::{lang_item::LangItemTarget, resolver::Resolver};
+use hir_def::lang_item::LangItemTarget;
 use hir_expand::name;
 use log::{info, warn};
+use ra_db::CrateId;
 
-use crate::{db::HirDatabase, Trait};
+use crate::db::HirDatabase;
 
-use super::{traits::Solution, Canonical, Substs, Ty, TypeWalk};
+use super::{
+    traits::{InEnvironment, Solution},
+    Canonical, Substs, Ty, TypeWalk,
+};
 
 const AUTODEREF_RECURSION_LIMIT: usize = 10;
 
-pub(crate) fn autoderef<'a>(
+pub fn autoderef<'a>(
     db: &'a impl HirDatabase,
-    resolver: &'a Resolver,
-    ty: Canonical<Ty>,
+    krate: Option<CrateId>,
+    ty: InEnvironment<Canonical<Ty>>,
 ) -> impl Iterator<Item = Canonical<Ty>> + 'a {
-    successors(Some(ty), move |ty| deref(db, resolver, ty)).take(AUTODEREF_RECURSION_LIMIT)
+    let InEnvironment { value: ty, environment } = ty;
+    successors(Some(ty), move |ty| {
+        deref(db, krate?, InEnvironment { value: ty, environment: environment.clone() })
+    })
+    .take(AUTODEREF_RECURSION_LIMIT)
 }
 
 pub(crate) fn deref(
     db: &impl HirDatabase,
-    resolver: &Resolver,
-    ty: &Canonical<Ty>,
+    krate: CrateId,
+    ty: InEnvironment<&Canonical<Ty>>,
 ) -> Option<Canonical<Ty>> {
-    if let Some(derefed) = ty.value.builtin_deref() {
-        Some(Canonical { value: derefed, num_vars: ty.num_vars })
+    if let Some(derefed) = ty.value.value.builtin_deref() {
+        Some(Canonical { value: derefed, num_vars: ty.value.num_vars })
     } else {
-        deref_by_trait(db, resolver, ty)
+        deref_by_trait(db, krate, ty)
     }
 }
 
 fn deref_by_trait(
     db: &impl HirDatabase,
-    resolver: &Resolver,
-    ty: &Canonical<Ty>,
+    krate: CrateId,
+    ty: InEnvironment<&Canonical<Ty>>,
 ) -> Option<Canonical<Ty>> {
-    let krate = resolver.krate()?;
     let deref_trait = match db.lang_item(krate.into(), "deref".into())? {
-        LangItemTarget::TraitId(t) => Trait::from(t),
+        LangItemTarget::TraitId(it) => it,
         _ => return None,
     };
-    let target = deref_trait.associated_type_by_name(db, &name::TARGET_TYPE)?;
+    let target = db.trait_data(deref_trait).associated_type_by_name(&name::TARGET_TYPE)?;
 
-    let generic_params = db.generic_params(target.id.into());
+    let generic_params = db.generic_params(target.into());
     if generic_params.count_params_including_parent() != 1 {
         // the Target type + Deref trait should only have one generic parameter,
         // namely Deref's Self type
@@ -56,10 +63,8 @@ fn deref_by_trait(
 
     // FIXME make the Canonical handling nicer
 
-    let env = super::lower::trait_env(db, resolver);
-
     let parameters = Substs::build_for_generics(&generic_params)
-        .push(ty.value.clone().shift_bound_vars(1))
+        .push(ty.value.value.clone().shift_bound_vars(1))
         .build();
 
     let projection = super::traits::ProjectionPredicate {
@@ -69,9 +74,9 @@ fn deref_by_trait(
 
     let obligation = super::Obligation::Projection(projection);
 
-    let in_env = super::traits::InEnvironment { value: obligation, environment: env };
+    let in_env = InEnvironment { value: obligation, environment: ty.environment };
 
-    let canonical = super::Canonical { num_vars: 1 + ty.num_vars, value: in_env };
+    let canonical = super::Canonical { num_vars: 1 + ty.value.num_vars, value: in_env };
 
     let solution = db.trait_solve(krate.into(), canonical)?;
 
@@ -89,14 +94,14 @@ fn deref_by_trait(
             // the case.
             for i in 1..vars.0.num_vars {
                 if vars.0.value[i] != Ty::Bound((i - 1) as u32) {
-                    warn!("complex solution for derefing {:?}: {:?}, ignoring", ty, solution);
+                    warn!("complex solution for derefing {:?}: {:?}, ignoring", ty.value, solution);
                     return None;
                 }
             }
             Some(Canonical { value: vars.0.value[0].clone(), num_vars: vars.0.num_vars })
         }
         Solution::Ambig(_) => {
-            info!("Ambiguous solution for derefing {:?}: {:?}", ty, solution);
+            info!("Ambiguous solution for derefing {:?}: {:?}", ty.value, solution);
             None
         }
     }
diff --git a/crates/ra_hir_ty/src/db.rs b/crates/ra_hir_ty/src/db.rs
new file mode 100644
index 000000000..9ce154593
--- /dev/null
+++ b/crates/ra_hir_ty/src/db.rs
@@ -0,0 +1,119 @@
+//! FIXME: write short doc here
+
+use std::sync::Arc;
+
+use hir_def::{
+    db::DefDatabase, DefWithBodyId, GenericDefId, ImplId, LocalStructFieldId, TraitId, VariantId,
+};
+use ra_arena::map::ArenaMap;
+use ra_db::{salsa, CrateId};
+
+use crate::{
+    method_resolution::CrateImplBlocks,
+    traits::{AssocTyValue, Impl},
+    CallableDef, FnSig, GenericPredicate, ImplTy, InferenceResult, Substs, Ty, TyDefId, TypeCtor,
+    ValueTyDefId,
+};
+
+#[salsa::query_group(HirDatabaseStorage)]
+#[salsa::requires(salsa::Database)]
+pub trait HirDatabase: DefDatabase {
+    #[salsa::invoke(crate::infer_query)]
+    fn infer(&self, def: DefWithBodyId) -> Arc<InferenceResult>;
+
+    #[salsa::invoke(crate::lower::ty_query)]
+    fn ty(&self, def: TyDefId) -> Ty;
+
+    #[salsa::invoke(crate::lower::value_ty_query)]
+    fn value_ty(&self, def: ValueTyDefId) -> Ty;
+
+    #[salsa::invoke(crate::lower::impl_ty_query)]
+    fn impl_ty(&self, def: ImplId) -> ImplTy;
+
+    #[salsa::invoke(crate::lower::field_types_query)]
+    fn field_types(&self, var: VariantId) -> Arc<ArenaMap<LocalStructFieldId, Ty>>;
+
+    #[salsa::invoke(crate::callable_item_sig)]
+    fn callable_item_signature(&self, def: CallableDef) -> FnSig;
+
+    #[salsa::invoke(crate::lower::generic_predicates_for_param_query)]
+    fn generic_predicates_for_param(
+        &self,
+        def: GenericDefId,
+        param_idx: u32,
+    ) -> Arc<[GenericPredicate]>;
+
+    #[salsa::invoke(crate::lower::generic_predicates_query)]
+    fn generic_predicates(&self, def: GenericDefId) -> Arc<[GenericPredicate]>;
+
+    #[salsa::invoke(crate::lower::generic_defaults_query)]
+    fn generic_defaults(&self, def: GenericDefId) -> Substs;
+
+    #[salsa::invoke(crate::method_resolution::CrateImplBlocks::impls_in_crate_query)]
+    fn impls_in_crate(&self, krate: CrateId) -> Arc<CrateImplBlocks>;
+
+    #[salsa::invoke(crate::traits::impls_for_trait_query)]
+    fn impls_for_trait(&self, krate: CrateId, trait_: TraitId) -> Arc<[ImplId]>;
+
+    /// This provides the Chalk trait solver instance. Because Chalk always
+    /// works from a specific crate, this query is keyed on the crate; and
+    /// because Chalk does its own internal caching, the solver is wrapped in a
+    /// Mutex and the query does an untracked read internally, to make sure the
+    /// cached state is thrown away when input facts change.
+    #[salsa::invoke(crate::traits::trait_solver_query)]
+    fn trait_solver(&self, krate: CrateId) -> crate::traits::TraitSolver;
+
+    // Interned IDs for Chalk integration
+    #[salsa::interned]
+    fn intern_type_ctor(&self, type_ctor: TypeCtor) -> crate::TypeCtorId;
+    #[salsa::interned]
+    fn intern_chalk_impl(&self, impl_: Impl) -> crate::traits::GlobalImplId;
+    #[salsa::interned]
+    fn intern_assoc_ty_value(&self, assoc_ty_value: AssocTyValue) -> crate::traits::AssocTyValueId;
+
+    #[salsa::invoke(crate::traits::chalk::associated_ty_data_query)]
+    fn associated_ty_data(
+        &self,
+        id: chalk_ir::TypeId,
+    ) -> Arc<chalk_rust_ir::AssociatedTyDatum<chalk_ir::family::ChalkIr>>;
+
+    #[salsa::invoke(crate::traits::chalk::trait_datum_query)]
+    fn trait_datum(
+        &self,
+        krate: CrateId,
+        trait_id: chalk_ir::TraitId,
+    ) -> Arc<chalk_rust_ir::TraitDatum<chalk_ir::family::ChalkIr>>;
+
+    #[salsa::invoke(crate::traits::chalk::struct_datum_query)]
+    fn struct_datum(
+        &self,
+        krate: CrateId,
+        struct_id: chalk_ir::StructId,
+    ) -> Arc<chalk_rust_ir::StructDatum<chalk_ir::family::ChalkIr>>;
+
+    #[salsa::invoke(crate::traits::chalk::impl_datum_query)]
+    fn impl_datum(
+        &self,
+        krate: CrateId,
+        impl_id: chalk_ir::ImplId,
+    ) -> Arc<chalk_rust_ir::ImplDatum<chalk_ir::family::ChalkIr>>;
+
+    #[salsa::invoke(crate::traits::chalk::associated_ty_value_query)]
+    fn associated_ty_value(
+        &self,
+        krate: CrateId,
+        id: chalk_rust_ir::AssociatedTyValueId,
+    ) -> Arc<chalk_rust_ir::AssociatedTyValue<chalk_ir::family::ChalkIr>>;
+
+    #[salsa::invoke(crate::traits::trait_solve_query)]
+    fn trait_solve(
+        &self,
+        krate: CrateId,
+        goal: crate::Canonical<crate::InEnvironment<crate::Obligation>>,
+    ) -> Option<crate::traits::Solution>;
+}
+
+#[test]
+fn hir_database_is_object_safe() {
+    fn _assert_object_safe(_: &dyn HirDatabase) {}
+}
diff --git a/crates/ra_hir_ty/src/diagnostics.rs b/crates/ra_hir_ty/src/diagnostics.rs
new file mode 100644
index 000000000..4a13fac23
--- /dev/null
+++ b/crates/ra_hir_ty/src/diagnostics.rs
@@ -0,0 +1,91 @@
+//! FIXME: write short doc here
+
+use std::any::Any;
+
+use hir_expand::{db::AstDatabase, name::Name, HirFileId, Source};
+use ra_syntax::{ast, AstNode, AstPtr, SyntaxNodePtr};
+
+pub use hir_def::diagnostics::UnresolvedModule;
+pub use hir_expand::diagnostics::{AstDiagnostic, Diagnostic, DiagnosticSink};
+
+#[derive(Debug)]
+pub struct NoSuchField {
+    pub file: HirFileId,
+    pub field: AstPtr<ast::RecordField>,
+}
+
+impl Diagnostic for NoSuchField {
+    fn message(&self) -> String {
+        "no such field".to_string()
+    }
+
+    fn source(&self) -> Source<SyntaxNodePtr> {
+        Source { file_id: self.file, value: self.field.into() }
+    }
+
+    fn as_any(&self) -> &(dyn Any + Send + 'static) {
+        self
+    }
+}
+
+#[derive(Debug)]
+pub struct MissingFields {
+    pub file: HirFileId,
+    pub field_list: AstPtr<ast::RecordFieldList>,
+    pub missed_fields: Vec<Name>,
+}
+
+impl Diagnostic for MissingFields {
+    fn message(&self) -> String {
+        use std::fmt::Write;
+        let mut message = String::from("Missing structure fields:\n");
+        for field in &self.missed_fields {
+            write!(message, "- {}\n", field).unwrap();
+        }
+        message
+    }
+    fn source(&self) -> Source<SyntaxNodePtr> {
+        Source { file_id: self.file, value: self.field_list.into() }
+    }
+    fn as_any(&self) -> &(dyn Any + Send + 'static) {
+        self
+    }
+}
+
+impl AstDiagnostic for MissingFields {
+    type AST = ast::RecordFieldList;
+
+    fn ast(&self, db: &impl AstDatabase) -> Self::AST {
+        let root = db.parse_or_expand(self.source().file_id).unwrap();
+        let node = self.source().value.to_node(&root);
+        ast::RecordFieldList::cast(node).unwrap()
+    }
+}
+
+#[derive(Debug)]
+pub struct MissingOkInTailExpr {
+    pub file: HirFileId,
+    pub expr: AstPtr<ast::Expr>,
+}
+
+impl Diagnostic for MissingOkInTailExpr {
+    fn message(&self) -> String {
+        "wrap return expression in Ok".to_string()
+    }
+    fn source(&self) -> Source<SyntaxNodePtr> {
+        Source { file_id: self.file, value: self.expr.into() }
+    }
+    fn as_any(&self) -> &(dyn Any + Send + 'static) {
+        self
+    }
+}
+
+impl AstDiagnostic for MissingOkInTailExpr {
+    type AST = ast::Expr;
+
+    fn ast(&self, db: &impl AstDatabase) -> Self::AST {
+        let root = db.parse_or_expand(self.file).unwrap();
+        let node = self.source().value.to_node(&root);
+        ast::Expr::cast(node).unwrap()
+    }
+}
diff --git a/crates/ra_hir/src/ty/display.rs b/crates/ra_hir_ty/src/display.rs
index 9bb3ece6c..9bb3ece6c 100644
--- a/crates/ra_hir/src/ty/display.rs
+++ b/crates/ra_hir_ty/src/display.rs
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir_ty/src/expr.rs
index 43fedde7a..5c65f9370 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir_ty/src/expr.rs
@@ -2,8 +2,12 @@
 
 use std::sync::Arc;
 
-use hir_def::{path::known, resolver::HasResolver};
-use hir_expand::diagnostics::DiagnosticSink;
+use hir_def::{
+    path::{known, Path},
+    resolver::HasResolver,
+    AdtId, FunctionId,
+};
+use hir_expand::{diagnostics::DiagnosticSink, name::Name};
 use ra_syntax::ast;
 use ra_syntax::AstPtr;
 use rustc_hash::FxHashSet;
@@ -11,8 +15,7 @@ use rustc_hash::FxHashSet;
 use crate::{
     db::HirDatabase,
     diagnostics::{MissingFields, MissingOkInTailExpr},
-    ty::{ApplicationTy, InferenceResult, Ty, TypeCtor},
-    Adt, Function, Name, Path,
+    ApplicationTy, InferenceResult, Ty, TypeCtor,
 };
 
 pub use hir_def::{
@@ -26,23 +29,23 @@ pub use hir_def::{
     },
 };
 
-pub(crate) struct ExprValidator<'a, 'b: 'a> {
-    func: Function,
+pub struct ExprValidator<'a, 'b: 'a> {
+    func: FunctionId,
     infer: Arc<InferenceResult>,
     sink: &'a mut DiagnosticSink<'b>,
 }
 
 impl<'a, 'b> ExprValidator<'a, 'b> {
-    pub(crate) fn new(
-        func: Function,
+    pub fn new(
+        func: FunctionId,
         infer: Arc<InferenceResult>,
         sink: &'a mut DiagnosticSink<'b>,
     ) -> ExprValidator<'a, 'b> {
         ExprValidator { func, infer, sink }
     }
 
-    pub(crate) fn validate_body(&mut self, db: &impl HirDatabase) {
-        let body = self.func.body(db);
+    pub fn validate_body(&mut self, db: &impl HirDatabase) {
+        let body = db.body(self.func.into());
 
         for e in body.exprs.iter() {
             if let (id, Expr::RecordLit { path, fields, spread }) = e {
@@ -69,16 +72,18 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
         }
 
         let struct_def = match self.infer[id].as_adt() {
-            Some((Adt::Struct(s), _)) => s,
+            Some((AdtId::StructId(s), _)) => s,
             _ => return,
         };
+        let struct_data = db.struct_data(struct_def);
 
         let lit_fields: FxHashSet<_> = fields.iter().map(|f| &f.name).collect();
-        let missed_fields: Vec<Name> = struct_def
-            .fields(db)
+        let missed_fields: Vec<Name> = struct_data
+            .variant_data
+            .fields()
             .iter()
-            .filter_map(|f| {
-                let name = f.name(db);
+            .filter_map(|(_f, d)| {
+                let name = d.name.clone();
                 if lit_fields.contains(&name) {
                     None
                 } else {
@@ -89,7 +94,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
         if missed_fields.is_empty() {
             return;
         }
-        let source_map = self.func.body_source_map(db);
+        let (_, source_map) = db.body_with_source_map(self.func.into());
 
         if let Some(source_ptr) = source_map.expr_syntax(id) {
             if let Some(expr) = source_ptr.value.a() {
@@ -121,20 +126,20 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
 
         let std_result_path = known::std_result_result();
 
-        let resolver = self.func.id.resolver(db);
+        let resolver = self.func.resolver(db);
         let std_result_enum = match resolver.resolve_known_enum(db, &std_result_path) {
             Some(it) => it,
             _ => return,
         };
 
-        let std_result_ctor = TypeCtor::Adt(Adt::Enum(std_result_enum.into()));
+        let std_result_ctor = TypeCtor::Adt(AdtId::EnumId(std_result_enum));
         let params = match &mismatch.expected {
             Ty::Apply(ApplicationTy { ctor, parameters }) if ctor == &std_result_ctor => parameters,
             _ => return,
         };
 
         if params.len() == 2 && &params[0] == &mismatch.actual {
-            let source_map = self.func.body_source_map(db);
+            let (_, source_map) = db.body_with_source_map(self.func.into());
 
             if let Some(source_ptr) = source_map.expr_syntax(id) {
                 if let Some(expr) = source_ptr.value.a() {
diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir_ty/src/infer.rs
index ddc7d262a..1e9f4b208 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir_ty/src/infer.rs
@@ -22,11 +22,13 @@ use ena::unify::{InPlaceUnificationTable, NoError, UnifyKey, UnifyValue};
 use rustc_hash::FxHashMap;
 
 use hir_def::{
+    body::Body,
     data::{ConstData, FunctionData},
-    path::known,
+    expr::{BindingAnnotation, ExprId, PatId},
+    path::{known, Path},
     resolver::{HasResolver, Resolver, TypeNs},
     type_ref::{Mutability, TypeRef},
-    AdtId, DefWithBodyId,
+    AdtId, AssocItemId, DefWithBodyId, FunctionId, StructFieldId, TypeAliasId, VariantId,
 };
 use hir_expand::{diagnostics::DiagnosticSink, name};
 use ra_arena::map::ArenaMap;
@@ -34,22 +36,16 @@ use ra_prof::profile;
 use test_utils::tested_by;
 
 use super::{
-    lower,
+    primitive::{FloatTy, IntTy},
     traits::{Guidance, Obligation, ProjectionPredicate, Solution},
-    ApplicationTy, InEnvironment, ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TypableDef,
-    TypeCtor, TypeWalk, Uncertain,
-};
-use crate::{
-    code_model::TypeAlias,
-    db::HirDatabase,
-    expr::{BindingAnnotation, Body, ExprId, PatId},
-    ty::infer::diagnostics::InferenceDiagnostic,
-    Adt, AssocItem, DefWithBody, FloatTy, Function, IntTy, Path, StructField, Trait, VariantDef,
+    ApplicationTy, InEnvironment, ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TypeCtor,
+    TypeWalk, Uncertain,
 };
+use crate::{db::HirDatabase, infer::diagnostics::InferenceDiagnostic};
 
 macro_rules! ty_app {
     ($ctor:pat, $param:pat) => {
-        crate::ty::Ty::Apply(crate::ty::ApplicationTy { ctor: $ctor, parameters: $param })
+        crate::Ty::Apply(crate::ApplicationTy { ctor: $ctor, parameters: $param })
     };
     ($ctor:pat) => {
         ty_app!($ctor, _)
@@ -63,15 +59,15 @@ mod pat;
 mod coerce;
 
 /// The entry point of type inference.
-pub fn infer_query(db: &impl HirDatabase, def: DefWithBody) -> Arc<InferenceResult> {
+pub fn infer_query(db: &impl HirDatabase, def: DefWithBodyId) -> Arc<InferenceResult> {
     let _p = profile("infer_query");
-    let resolver = DefWithBodyId::from(def).resolver(db);
+    let resolver = def.resolver(db);
     let mut ctx = InferenceContext::new(db, def, resolver);
 
-    match &def {
-        DefWithBody::Const(c) => ctx.collect_const(&db.const_data(c.id)),
-        DefWithBody::Function(f) => ctx.collect_fn(&db.function_data(f.id)),
-        DefWithBody::Static(s) => ctx.collect_const(&db.static_data(s.id)),
+    match def {
+        DefWithBodyId::ConstId(c) => ctx.collect_const(&db.const_data(c)),
+        DefWithBodyId::FunctionId(f) => ctx.collect_fn(&db.function_data(f)),
+        DefWithBodyId::StaticId(s) => ctx.collect_const(&db.static_data(s)),
     }
 
     ctx.infer_body();
@@ -122,50 +118,50 @@ pub struct TypeMismatch {
 #[derive(Clone, PartialEq, Eq, Debug, Default)]
 pub struct InferenceResult {
     /// For each method call expr, records the function it resolves to.
-    method_resolutions: FxHashMap<ExprId, Function>,
+    method_resolutions: FxHashMap<ExprId, FunctionId>,
     /// For each field access expr, records the field it resolves to.
-    field_resolutions: FxHashMap<ExprId, StructField>,
+    field_resolutions: FxHashMap<ExprId, StructFieldId>,
     /// For each field in record literal, records the field it resolves to.
-    record_field_resolutions: FxHashMap<ExprId, StructField>,
+    record_field_resolutions: FxHashMap<ExprId, StructFieldId>,
     /// For each struct literal, records the variant it resolves to.
-    variant_resolutions: FxHashMap<ExprOrPatId, VariantDef>,
+    variant_resolutions: FxHashMap<ExprOrPatId, VariantId>,
     /// For each associated item record what it resolves to
-    assoc_resolutions: FxHashMap<ExprOrPatId, AssocItem>,
+    assoc_resolutions: FxHashMap<ExprOrPatId, AssocItemId>,
     diagnostics: Vec<InferenceDiagnostic>,
-    pub(super) type_of_expr: ArenaMap<ExprId, Ty>,
-    pub(super) type_of_pat: ArenaMap<PatId, Ty>,
+    pub type_of_expr: ArenaMap<ExprId, Ty>,
+    pub type_of_pat: ArenaMap<PatId, Ty>,
     pub(super) type_mismatches: ArenaMap<ExprId, TypeMismatch>,
 }
 
 impl InferenceResult {
-    pub fn method_resolution(&self, expr: ExprId) -> Option<Function> {
+    pub fn method_resolution(&self, expr: ExprId) -> Option<FunctionId> {
         self.method_resolutions.get(&expr).copied()
     }
-    pub fn field_resolution(&self, expr: ExprId) -> Option<StructField> {
+    pub fn field_resolution(&self, expr: ExprId) -> Option<StructFieldId> {
         self.field_resolutions.get(&expr).copied()
     }
-    pub fn record_field_resolution(&self, expr: ExprId) -> Option<StructField> {
+    pub fn record_field_resolution(&self, expr: ExprId) -> Option<StructFieldId> {
         self.record_field_resolutions.get(&expr).copied()
     }
-    pub fn variant_resolution_for_expr(&self, id: ExprId) -> Option<VariantDef> {
+    pub fn variant_resolution_for_expr(&self, id: ExprId) -> Option<VariantId> {
         self.variant_resolutions.get(&id.into()).copied()
     }
-    pub fn variant_resolution_for_pat(&self, id: PatId) -> Option<VariantDef> {
+    pub fn variant_resolution_for_pat(&self, id: PatId) -> Option<VariantId> {
         self.variant_resolutions.get(&id.into()).copied()
     }
-    pub fn assoc_resolutions_for_expr(&self, id: ExprId) -> Option<AssocItem> {
+    pub fn assoc_resolutions_for_expr(&self, id: ExprId) -> Option<AssocItemId> {
         self.assoc_resolutions.get(&id.into()).copied()
     }
-    pub fn assoc_resolutions_for_pat(&self, id: PatId) -> Option<AssocItem> {
+    pub fn assoc_resolutions_for_pat(&self, id: PatId) -> Option<AssocItemId> {
         self.assoc_resolutions.get(&id.into()).copied()
     }
     pub fn type_mismatch_for_expr(&self, expr: ExprId) -> Option<&TypeMismatch> {
         self.type_mismatches.get(expr)
     }
-    pub(crate) fn add_diagnostics(
+    pub fn add_diagnostics(
         &self,
         db: &impl HirDatabase,
-        owner: Function,
+        owner: FunctionId,
         sink: &mut DiagnosticSink,
     ) {
         self.diagnostics.iter().for_each(|it| it.add_to(db, owner, sink))
@@ -192,7 +188,7 @@ impl Index<PatId> for InferenceResult {
 #[derive(Clone, Debug)]
 struct InferenceContext<'a, D: HirDatabase> {
     db: &'a D,
-    owner: DefWithBody,
+    owner: DefWithBodyId,
     body: Arc<Body>,
     resolver: Resolver,
     var_unification_table: InPlaceUnificationTable<TypeVarId>,
@@ -210,13 +206,13 @@ struct InferenceContext<'a, D: HirDatabase> {
 }
 
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
-    fn new(db: &'a D, owner: DefWithBody, resolver: Resolver) -> Self {
+    fn new(db: &'a D, owner: DefWithBodyId, resolver: Resolver) -> Self {
         InferenceContext {
             result: InferenceResult::default(),
             var_unification_table: InPlaceUnificationTable::new(),
             obligations: Vec::default(),
             return_ty: Ty::Unknown, // set in collect_fn_signature
-            trait_env: lower::trait_env(db, &resolver),
+            trait_env: TraitEnvironment::lower(db, &resolver),
             coerce_unsized_map: Self::init_coerce_unsized_map(db, &resolver),
             db,
             owner,
@@ -244,20 +240,20 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         self.result.type_of_expr.insert(expr, ty);
     }
 
-    fn write_method_resolution(&mut self, expr: ExprId, func: Function) {
+    fn write_method_resolution(&mut self, expr: ExprId, func: FunctionId) {
         self.result.method_resolutions.insert(expr, func);
     }
 
-    fn write_field_resolution(&mut self, expr: ExprId, field: StructField) {
+    fn write_field_resolution(&mut self, expr: ExprId, field: StructFieldId) {
         self.result.field_resolutions.insert(expr, field);
     }
 
-    fn write_variant_resolution(&mut self, id: ExprOrPatId, variant: VariantDef) {
+    fn write_variant_resolution(&mut self, id: ExprOrPatId, variant: VariantId) {
         self.result.variant_resolutions.insert(id, variant);
     }
 
-    fn write_assoc_resolution(&mut self, id: ExprOrPatId, item: AssocItem) {
-        self.result.assoc_resolutions.insert(id, item);
+    fn write_assoc_resolution(&mut self, id: ExprOrPatId, item: AssocItemId) {
+        self.result.assoc_resolutions.insert(id, item.into());
     }
 
     fn write_pat_ty(&mut self, pat: PatId, ty: Ty) {
@@ -515,51 +511,28 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         })
     }
 
-    fn resolve_variant(&mut self, path: Option<&Path>) -> (Ty, Option<VariantDef>) {
+    fn resolve_variant(&mut self, path: Option<&Path>) -> (Ty, Option<VariantId>) {
         let path = match path {
             Some(path) => path,
             None => return (Ty::Unknown, None),
         };
         let resolver = &self.resolver;
-        let def: TypableDef =
-            // FIXME: this should resolve assoc items as well, see this example:
-            // https://play.rust-lang.org/?gist=087992e9e22495446c01c0d4e2d69521
-            match resolver.resolve_path_in_type_ns_fully(self.db, &path) {
-                Some(TypeNs::AdtId(AdtId::StructId(it))) => it.into(),
-                Some(TypeNs::AdtId(AdtId::UnionId(it))) => it.into(),
-                Some(TypeNs::AdtSelfType(adt)) => adt.into(),
-                Some(TypeNs::EnumVariantId(it)) => it.into(),
-                Some(TypeNs::TypeAliasId(it)) => it.into(),
-
-                Some(TypeNs::SelfType(_)) |
-                Some(TypeNs::GenericParam(_)) |
-                Some(TypeNs::BuiltinType(_)) |
-                Some(TypeNs::TraitId(_)) |
-                Some(TypeNs::AdtId(AdtId::EnumId(_))) |
-                None => {
-                    return (Ty::Unknown, None)
-                }
-            };
-        // FIXME remove the duplication between here and `Ty::from_path`?
-        let substs = Ty::substs_from_path(self.db, resolver, path, def);
-        match def {
-            TypableDef::Adt(Adt::Struct(s)) => {
-                let ty = s.ty(self.db);
+        // FIXME: this should resolve assoc items as well, see this example:
+        // https://play.rust-lang.org/?gist=087992e9e22495446c01c0d4e2d69521
+        match resolver.resolve_path_in_type_ns_fully(self.db, &path) {
+            Some(TypeNs::AdtId(AdtId::StructId(strukt))) => {
+                let substs = Ty::substs_from_path(self.db, resolver, path, strukt.into());
+                let ty = self.db.ty(strukt.into());
                 let ty = self.insert_type_vars(ty.apply_substs(substs));
-                (ty, Some(s.into()))
+                (ty, Some(strukt.into()))
             }
-            TypableDef::EnumVariant(var) => {
-                let ty = var.parent_enum(self.db).ty(self.db);
+            Some(TypeNs::EnumVariantId(var)) => {
+                let substs = Ty::substs_from_path(self.db, resolver, path, var.into());
+                let ty = self.db.ty(var.parent.into());
                 let ty = self.insert_type_vars(ty.apply_substs(substs));
                 (ty, Some(var.into()))
             }
-            TypableDef::Adt(Adt::Enum(_))
-            | TypableDef::Adt(Adt::Union(_))
-            | TypableDef::TypeAlias(_)
-            | TypableDef::Function(_)
-            | TypableDef::Const(_)
-            | TypableDef::Static(_)
-            | TypableDef::BuiltinType(_) => (Ty::Unknown, None),
+            Some(_) | None => (Ty::Unknown, None),
         }
     }
 
@@ -581,28 +554,28 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         self.infer_expr(self.body.body_expr, &Expectation::has_type(self.return_ty.clone()));
     }
 
-    fn resolve_into_iter_item(&self) -> Option<TypeAlias> {
+    fn resolve_into_iter_item(&self) -> Option<TypeAliasId> {
         let path = known::std_iter_into_iterator();
-        let trait_: Trait = self.resolver.resolve_known_trait(self.db, &path)?.into();
-        trait_.associated_type_by_name(self.db, &name::ITEM_TYPE)
+        let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
+        self.db.trait_data(trait_).associated_type_by_name(&name::ITEM_TYPE)
     }
 
-    fn resolve_ops_try_ok(&self) -> Option<TypeAlias> {
+    fn resolve_ops_try_ok(&self) -> Option<TypeAliasId> {
         let path = known::std_ops_try();
-        let trait_: Trait = self.resolver.resolve_known_trait(self.db, &path)?.into();
-        trait_.associated_type_by_name(self.db, &name::OK_TYPE)
+        let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
+        self.db.trait_data(trait_).associated_type_by_name(&name::OK_TYPE)
     }
 
-    fn resolve_future_future_output(&self) -> Option<TypeAlias> {
+    fn resolve_future_future_output(&self) -> Option<TypeAliasId> {
         let path = known::std_future_future();
-        let trait_: Trait = self.resolver.resolve_known_trait(self.db, &path)?.into();
-        trait_.associated_type_by_name(self.db, &name::OUTPUT_TYPE)
+        let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
+        self.db.trait_data(trait_).associated_type_by_name(&name::OUTPUT_TYPE)
     }
 
-    fn resolve_boxed_box(&self) -> Option<Adt> {
+    fn resolve_boxed_box(&self) -> Option<AdtId> {
         let path = known::std_boxed_box();
         let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
-        Some(Adt::Struct(struct_.into()))
+        Some(struct_.into())
     }
 }
 
@@ -720,9 +693,10 @@ impl Expectation {
 }
 
 mod diagnostics {
+    use hir_def::{expr::ExprId, FunctionId, HasSource, Lookup};
     use hir_expand::diagnostics::DiagnosticSink;
 
-    use crate::{db::HirDatabase, diagnostics::NoSuchField, expr::ExprId, Function, HasSource};
+    use crate::{db::HirDatabase, diagnostics::NoSuchField};
 
     #[derive(Debug, PartialEq, Eq, Clone)]
     pub(super) enum InferenceDiagnostic {
@@ -733,13 +707,14 @@ mod diagnostics {
         pub(super) fn add_to(
             &self,
             db: &impl HirDatabase,
-            owner: Function,
+            owner: FunctionId,
             sink: &mut DiagnosticSink,
         ) {
             match self {
                 InferenceDiagnostic::NoSuchField { expr, field } => {
-                    let file = owner.source(db).file_id;
-                    let field = owner.body_source_map(db).field_syntax(*expr, *field);
+                    let file = owner.lookup(db).source(db).file_id;
+                    let (_, source_map) = db.body_with_source_map(owner.into());
+                    let field = source_map.field_syntax(*expr, *field);
                     sink.push(NoSuchField { file, field })
                 }
             }
diff --git a/crates/ra_hir/src/ty/infer/coerce.rs b/crates/ra_hir_ty/src/infer/coerce.rs
index 54765da35..719a0f395 100644
--- a/crates/ra_hir/src/ty/infer/coerce.rs
+++ b/crates/ra_hir_ty/src/infer/coerce.rs
@@ -4,17 +4,13 @@
 //!
 //! See: https://doc.rust-lang.org/nomicon/coercions.html
 
-use hir_def::{lang_item::LangItemTarget, resolver::Resolver};
+use hir_def::{lang_item::LangItemTarget, resolver::Resolver, type_ref::Mutability, AdtId};
 use rustc_hash::FxHashMap;
 use test_utils::tested_by;
 
-use crate::{
-    db::HirDatabase,
-    ty::{autoderef, Substs, Ty, TypeCtor, TypeWalk},
-    Adt, Mutability,
-};
+use crate::{autoderef, db::HirDatabase, ImplTy, Substs, Ty, TypeCtor, TypeWalk};
 
-use super::{InferTy, InferenceContext, TypeVarValue};
+use super::{InEnvironment, InferTy, InferenceContext, TypeVarValue};
 
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     /// Unify two types, but may coerce the first one to the second one
@@ -57,9 +53,13 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
         impls
             .iter()
-            .filter_map(|impl_block| {
+            .filter_map(|&impl_id| {
+                let trait_ref = match db.impl_ty(impl_id) {
+                    ImplTy::TraitRef(it) => it,
+                    ImplTy::Inherent(_) => return None,
+                };
+
                 // `CoerseUnsized` has one generic parameter for the target type.
-                let trait_ref = impl_block.target_trait_ref(db)?;
                 let cur_from_ty = trait_ref.substs.0.get(0)?;
                 let cur_to_ty = trait_ref.substs.0.get(1)?;
 
@@ -242,11 +242,11 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             // - T is not part of the type of any other fields
             // - Bar<T>: Unsize<Bar<U>>, if the last field of Foo has type Bar<T>
             (
-                ty_app!(TypeCtor::Adt(Adt::Struct(struct1)), st1),
-                ty_app!(TypeCtor::Adt(Adt::Struct(struct2)), st2),
+                ty_app!(TypeCtor::Adt(AdtId::StructId(struct1)), st1),
+                ty_app!(TypeCtor::Adt(AdtId::StructId(struct2)), st2),
             ) if struct1 == struct2 => {
-                let field_tys = self.db.field_types(struct1.id.into());
-                let struct_data = self.db.struct_data(struct1.id.0);
+                let field_tys = self.db.field_types((*struct1).into());
+                let struct_data = self.db.struct_data(*struct1);
 
                 let mut fields = struct_data.variant_data.fields().iter();
                 let (last_field_id, _data) = fields.next_back()?;
@@ -320,9 +320,14 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         let canonicalized = self.canonicalizer().canonicalize_ty(from_ty.clone());
         let to_ty = self.resolve_ty_shallow(&to_ty);
         // FIXME: Auto DerefMut
-        for derefed_ty in
-            autoderef::autoderef(self.db, &self.resolver.clone(), canonicalized.value.clone())
-        {
+        for derefed_ty in autoderef::autoderef(
+            self.db,
+            self.resolver.krate(),
+            InEnvironment {
+                value: canonicalized.value.clone(),
+                environment: self.trait_env.clone(),
+            },
+        ) {
             let derefed_ty = canonicalized.decanonicalize_ty(derefed_ty.value);
             match (&*self.resolve_ty_shallow(&derefed_ty), &*to_ty) {
                 // Stop when constructor matches.
diff --git a/crates/ra_hir/src/ty/infer/expr.rs b/crates/ra_hir_ty/src/infer/expr.rs
index 663ff9435..2f9ca4bbb 100644
--- a/crates/ra_hir/src/ty/infer/expr.rs
+++ b/crates/ra_hir_ty/src/infer/expr.rs
@@ -5,21 +5,18 @@ use std::sync::Arc;
 
 use hir_def::{
     builtin_type::Signedness,
+    expr::{Array, BinaryOp, Expr, ExprId, Literal, Statement, UnaryOp},
     generics::GenericParams,
     path::{GenericArg, GenericArgs},
     resolver::resolver_for_expr,
+    AdtId, ContainerId, Lookup, StructFieldId,
 };
-use hir_expand::name;
+use hir_expand::name::{self, Name};
 
 use crate::{
-    db::HirDatabase,
-    expr::{Array, BinaryOp, Expr, ExprId, Literal, Statement, UnaryOp},
-    ty::{
-        autoderef, method_resolution, op, CallableDef, InferTy, IntTy, Mutability, Namespace,
-        Obligation, ProjectionPredicate, ProjectionTy, Substs, TraitRef, Ty, TypeCtor, TypeWalk,
-        Uncertain,
-    },
-    Adt, Name,
+    autoderef, db::HirDatabase, method_resolution, op, traits::InEnvironment, utils::variant_data,
+    CallableDef, InferTy, IntTy, Mutability, Obligation, ProjectionPredicate, ProjectionTy, Substs,
+    TraitRef, Ty, TypeCtor, TypeWalk, Uncertain,
 };
 
 use super::{BindingMode, Expectation, InferenceContext, InferenceDiagnostic, TypeMismatch};
@@ -136,8 +133,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     TypeCtor::FnPtr { num_args: sig_tys.len() as u16 - 1 },
                     Substs(sig_tys.into()),
                 );
-                let closure_ty =
-                    Ty::apply_one(TypeCtor::Closure { def: self.owner, expr: tgt_expr }, sig_ty);
+                let closure_ty = Ty::apply_one(
+                    TypeCtor::Closure { def: self.owner.into(), expr: tgt_expr },
+                    sig_ty,
+                );
 
                 // Eagerly try to relate the closure type with the expected
                 // type, otherwise we often won't have enough information to
@@ -216,22 +215,26 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 let substs = ty.substs().unwrap_or_else(Substs::empty);
                 let field_types =
                     def_id.map(|it| self.db.field_types(it.into())).unwrap_or_default();
+                let variant_data = def_id.map(|it| variant_data(self.db, it));
                 for (field_idx, field) in fields.iter().enumerate() {
-                    let field_def = def_id.and_then(|it| match it.field(self.db, &field.name) {
-                        Some(field) => Some(field),
-                        None => {
-                            self.push_diagnostic(InferenceDiagnostic::NoSuchField {
-                                expr: tgt_expr,
-                                field: field_idx,
-                            });
-                            None
-                        }
-                    });
+                    let field_def =
+                        variant_data.as_ref().and_then(|it| match it.field(&field.name) {
+                            Some(local_id) => {
+                                Some(StructFieldId { parent: def_id.unwrap(), local_id })
+                            }
+                            None => {
+                                self.push_diagnostic(InferenceDiagnostic::NoSuchField {
+                                    expr: tgt_expr,
+                                    field: field_idx,
+                                });
+                                None
+                            }
+                        });
                     if let Some(field_def) = field_def {
                         self.result.record_field_resolutions.insert(field.expr, field_def);
                     }
                     let field_ty = field_def
-                        .map_or(Ty::Unknown, |it| field_types[it.id].clone())
+                        .map_or(Ty::Unknown, |it| field_types[it.local_id].clone())
                         .subst(&substs);
                     self.infer_expr_coerce(field.expr, &Expectation::has_type(field_ty));
                 }
@@ -245,20 +248,28 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 let canonicalized = self.canonicalizer().canonicalize_ty(receiver_ty);
                 let ty = autoderef::autoderef(
                     self.db,
-                    &self.resolver.clone(),
-                    canonicalized.value.clone(),
+                    self.resolver.krate(),
+                    InEnvironment {
+                        value: canonicalized.value.clone(),
+                        environment: self.trait_env.clone(),
+                    },
                 )
                 .find_map(|derefed_ty| match canonicalized.decanonicalize_ty(derefed_ty.value) {
                     Ty::Apply(a_ty) => match a_ty.ctor {
                         TypeCtor::Tuple { .. } => name
                             .as_tuple_index()
                             .and_then(|idx| a_ty.parameters.0.get(idx).cloned()),
-                        TypeCtor::Adt(Adt::Struct(s)) => s.field(self.db, name).map(|field| {
-                            self.write_field_resolution(tgt_expr, field);
-                            self.db.field_types(s.id.into())[field.id]
-                                .clone()
-                                .subst(&a_ty.parameters)
-                        }),
+                        TypeCtor::Adt(AdtId::StructId(s)) => {
+                            self.db.struct_data(s).variant_data.field(name).map(|local_id| {
+                                let field = StructFieldId { parent: s.into(), local_id }.into();
+                                self.write_field_resolution(tgt_expr, field);
+                                self.db.field_types(s.into())[field.local_id]
+                                    .clone()
+                                    .subst(&a_ty.parameters)
+                            })
+                        }
+                        // FIXME:
+                        TypeCtor::Adt(AdtId::UnionId(_)) => None,
                         _ => None,
                     },
                     _ => None,
@@ -337,16 +348,25 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             Expr::UnaryOp { expr, op } => {
                 let inner_ty = self.infer_expr(*expr, &Expectation::none());
                 match op {
-                    UnaryOp::Deref => {
-                        let canonicalized = self.canonicalizer().canonicalize_ty(inner_ty);
-                        if let Some(derefed_ty) =
-                            autoderef::deref(self.db, &self.resolver, &canonicalized.value)
-                        {
-                            canonicalized.decanonicalize_ty(derefed_ty.value)
-                        } else {
-                            Ty::Unknown
+                    UnaryOp::Deref => match self.resolver.krate() {
+                        Some(krate) => {
+                            let canonicalized = self.canonicalizer().canonicalize_ty(inner_ty);
+                            match autoderef::deref(
+                                self.db,
+                                krate,
+                                InEnvironment {
+                                    value: &canonicalized.value,
+                                    environment: self.trait_env.clone(),
+                                },
+                            ) {
+                                Some(derefed_ty) => {
+                                    canonicalized.decanonicalize_ty(derefed_ty.value)
+                                }
+                                None => Ty::Unknown,
+                            }
                         }
-                    }
+                        None => Ty::Unknown,
+                    },
                     UnaryOp::Neg => {
                         match &inner_ty {
                             Ty::Apply(a_ty) => match a_ty.ctor {
@@ -538,11 +558,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             Some((ty, func)) => {
                 let ty = canonicalized_receiver.decanonicalize_ty(ty);
                 self.write_method_resolution(tgt_expr, func);
-                (
-                    ty,
-                    self.db.type_for_def(func.into(), Namespace::Values),
-                    Some(self.db.generic_params(func.id.into())),
-                )
+                (ty, self.db.value_ty(func.into()), Some(self.db.generic_params(func.into())))
             }
             None => (receiver_ty, Ty::Unknown, None),
         };
@@ -648,18 +664,21 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 }
                 // add obligation for trait implementation, if this is a trait method
                 match def {
-                    CallableDef::Function(f) => {
-                        if let Some(trait_) = f.parent_trait(self.db) {
+                    CallableDef::FunctionId(f) => {
+                        if let ContainerId::TraitId(trait_) = f.lookup(self.db).container {
                             // construct a TraitDef
                             let substs = a_ty.parameters.prefix(
                                 self.db
-                                    .generic_params(trait_.id.into())
+                                    .generic_params(trait_.into())
                                     .count_params_including_parent(),
                             );
-                            self.obligations.push(Obligation::Trait(TraitRef { trait_, substs }));
+                            self.obligations.push(Obligation::Trait(TraitRef {
+                                trait_: trait_.into(),
+                                substs,
+                            }));
                         }
                     }
-                    CallableDef::Struct(_) | CallableDef::EnumVariant(_) => {}
+                    CallableDef::StructId(_) | CallableDef::EnumVariantId(_) => {}
                 }
             }
         }
diff --git a/crates/ra_hir/src/ty/infer/pat.rs b/crates/ra_hir_ty/src/infer/pat.rs
index 641d61e87..1ebb36239 100644
--- a/crates/ra_hir/src/ty/infer/pat.rs
+++ b/crates/ra_hir_ty/src/infer/pat.rs
@@ -3,15 +3,16 @@
 use std::iter::repeat;
 use std::sync::Arc;
 
+use hir_def::{
+    expr::{BindingAnnotation, Pat, PatId, RecordFieldPat},
+    path::Path,
+    type_ref::Mutability,
+};
+use hir_expand::name::Name;
 use test_utils::tested_by;
 
 use super::{BindingMode, InferenceContext};
-use crate::{
-    db::HirDatabase,
-    expr::{BindingAnnotation, Pat, PatId, RecordFieldPat},
-    ty::{Mutability, Substs, Ty, TypeCtor, TypeWalk},
-    Name, Path,
-};
+use crate::{db::HirDatabase, utils::variant_data, Substs, Ty, TypeCtor, TypeWalk};
 
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     fn infer_tuple_struct_pat(
@@ -22,16 +23,18 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         default_bm: BindingMode,
     ) -> Ty {
         let (ty, def) = self.resolve_variant(path);
-
+        let var_data = def.map(|it| variant_data(self.db, it));
         self.unify(&ty, expected);
 
         let substs = ty.substs().unwrap_or_else(Substs::empty);
 
         let field_tys = def.map(|it| self.db.field_types(it.into())).unwrap_or_default();
+
         for (i, &subpat) in subpats.iter().enumerate() {
-            let expected_ty = def
-                .and_then(|d| d.field(self.db, &Name::new_tuple_field(i)))
-                .map_or(Ty::Unknown, |field| field_tys[field.id].clone())
+            let expected_ty = var_data
+                .as_ref()
+                .and_then(|d| d.field(&Name::new_tuple_field(i)))
+                .map_or(Ty::Unknown, |field| field_tys[field].clone())
                 .subst(&substs);
             let expected_ty = self.normalize_associated_types_in(expected_ty);
             self.infer_pat(subpat, &expected_ty, default_bm);
@@ -49,6 +52,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         id: PatId,
     ) -> Ty {
         let (ty, def) = self.resolve_variant(path);
+        let var_data = def.map(|it| variant_data(self.db, it));
         if let Some(variant) = def {
             self.write_variant_resolution(id.into(), variant);
         }
@@ -59,10 +63,9 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
         let field_tys = def.map(|it| self.db.field_types(it.into())).unwrap_or_default();
         for subpat in subpats {
-            let matching_field = def.and_then(|it| it.field(self.db, &subpat.name));
-            let expected_ty = matching_field
-                .map_or(Ty::Unknown, |field| field_tys[field.id].clone())
-                .subst(&substs);
+            let matching_field = var_data.as_ref().and_then(|it| it.field(&subpat.name));
+            let expected_ty =
+                matching_field.map_or(Ty::Unknown, |field| field_tys[field].clone()).subst(&substs);
             let expected_ty = self.normalize_associated_types_in(expected_ty);
             self.infer_pat(subpat.pat, &expected_ty, default_bm);
         }
diff --git a/crates/ra_hir/src/ty/infer/path.rs b/crates/ra_hir_ty/src/infer/path.rs
index ee54d8217..14be66836 100644
--- a/crates/ra_hir/src/ty/infer/path.rs
+++ b/crates/ra_hir_ty/src/infer/path.rs
@@ -1,15 +1,13 @@
 //! Path expression resolution.
 
 use hir_def::{
-    path::PathSegment,
+    path::{Path, PathKind, PathSegment},
     resolver::{ResolveValueResult, Resolver, TypeNs, ValueNs},
+    AssocItemId, ContainerId, Lookup,
 };
+use hir_expand::name::Name;
 
-use crate::{
-    db::HirDatabase,
-    ty::{method_resolution, Namespace, Substs, Ty, TypableDef, TypeWalk},
-    AssocItem, Container, Function, Name, Path,
-};
+use crate::{db::HirDatabase, method_resolution, Substs, Ty, TypeWalk, ValueTyDefId};
 
 use super::{ExprOrPatId, InferenceContext, TraitRef};
 
@@ -32,7 +30,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         path: &Path,
         id: ExprOrPatId,
     ) -> Option<Ty> {
-        let (value, self_subst) = if let crate::PathKind::Type(type_ref) = &path.kind {
+        let (value, self_subst) = if let PathKind::Type(type_ref) = &path.kind {
             if path.segments.is_empty() {
                 // This can't actually happen syntax-wise
                 return None;
@@ -56,7 +54,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             }
         };
 
-        let typable: TypableDef = match value {
+        let typable: ValueTyDefId = match value {
             ValueNs::LocalBinding(pat) => {
                 let ty = self.result.type_of_pat.get(pat)?.clone();
                 let ty = self.resolve_ty_as_possible(&mut vec![], ty);
@@ -69,11 +67,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             ValueNs::EnumVariantId(it) => it.into(),
         };
 
-        let mut ty = self.db.type_for_def(typable, Namespace::Values);
+        let mut ty = self.db.value_ty(typable);
         if let Some(self_subst) = self_subst {
             ty = ty.subst(&self_subst);
         }
-
         let substs = Ty::substs_from_path(self.db, &self.resolver, path, typable);
         let ty = ty.subst(&substs);
         Some(ty)
@@ -143,28 +140,35 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         id: ExprOrPatId,
     ) -> Option<(ValueNs, Option<Substs>)> {
         let trait_ = trait_ref.trait_;
-        let item = trait_.items(self.db).iter().copied().find_map(|item| match item {
-            AssocItem::Function(func) => {
-                if segment.name == func.name(self.db) {
-                    Some(AssocItem::Function(func))
-                } else {
-                    None
+        let item = self
+            .db
+            .trait_data(trait_)
+            .items
+            .iter()
+            .map(|(_name, id)| (*id).into())
+            .find_map(|item| match item {
+                AssocItemId::FunctionId(func) => {
+                    if segment.name == self.db.function_data(func).name {
+                        Some(AssocItemId::FunctionId(func))
+                    } else {
+                        None
+                    }
                 }
-            }
 
-            AssocItem::Const(konst) => {
-                if konst.name(self.db).map_or(false, |n| n == segment.name) {
-                    Some(AssocItem::Const(konst))
-                } else {
-                    None
+                AssocItemId::ConstId(konst) => {
+                    if self.db.const_data(konst).name.as_ref().map_or(false, |n| n == &segment.name)
+                    {
+                        Some(AssocItemId::ConstId(konst))
+                    } else {
+                        None
+                    }
                 }
-            }
-            AssocItem::TypeAlias(_) => None,
-        })?;
+                AssocItemId::TypeAliasId(_) => None,
+            })?;
         let def = match item {
-            AssocItem::Function(f) => ValueNs::FunctionId(f.id),
-            AssocItem::Const(c) => ValueNs::ConstId(c.id),
-            AssocItem::TypeAlias(_) => unreachable!(),
+            AssocItemId::FunctionId(f) => ValueNs::FunctionId(f),
+            AssocItemId::ConstId(c) => ValueNs::ConstId(c),
+            AssocItemId::TypeAliasId(_) => unreachable!(),
         };
         let substs = Substs::build_for_def(self.db, item)
             .use_parent_substs(&trait_ref.substs)
@@ -194,16 +198,18 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             Some(name),
             method_resolution::LookupMode::Path,
             move |_ty, item| {
-                let def = match item {
-                    AssocItem::Function(f) => ValueNs::FunctionId(f.id),
-                    AssocItem::Const(c) => ValueNs::ConstId(c.id),
-                    AssocItem::TypeAlias(_) => unreachable!(),
+                let (def, container) = match item {
+                    AssocItemId::FunctionId(f) => {
+                        (ValueNs::FunctionId(f), f.lookup(self.db).container)
+                    }
+                    AssocItemId::ConstId(c) => (ValueNs::ConstId(c), c.lookup(self.db).container),
+                    AssocItemId::TypeAliasId(_) => unreachable!(),
                 };
-                let substs = match item.container(self.db) {
-                    Container::ImplBlock(_) => self.find_self_types(&def, ty.clone()),
-                    Container::Trait(t) => {
+                let substs = match container {
+                    ContainerId::ImplId(_) => self.find_self_types(&def, ty.clone()),
+                    ContainerId::TraitId(trait_) => {
                         // we're picking this method
-                        let trait_substs = Substs::build_for_def(self.db, t)
+                        let trait_substs = Substs::build_for_def(self.db, trait_)
                             .push(ty.clone())
                             .fill(std::iter::repeat_with(|| self.new_type_var()))
                             .build();
@@ -212,37 +218,41 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                             .fill_with_params()
                             .build();
                         self.obligations.push(super::Obligation::Trait(TraitRef {
-                            trait_: t,
+                            trait_,
                             substs: trait_substs,
                         }));
                         Some(substs)
                     }
+                    ContainerId::ModuleId(_) => None,
                 };
 
-                self.write_assoc_resolution(id, item);
+                self.write_assoc_resolution(id, item.into());
                 Some((def, substs))
             },
         )
     }
 
     fn find_self_types(&self, def: &ValueNs, actual_def_ty: Ty) -> Option<Substs> {
-        if let ValueNs::FunctionId(func) = def {
-            let func = Function::from(*func);
+        if let ValueNs::FunctionId(func) = *def {
             // We only do the infer if parent has generic params
-            let gen = self.db.generic_params(func.id.into());
+            let gen = self.db.generic_params(func.into());
             if gen.count_parent_params() == 0 {
                 return None;
             }
 
-            let impl_block = func.impl_block(self.db)?.target_ty(self.db);
-            let impl_block_substs = impl_block.substs()?;
+            let impl_id = match func.lookup(self.db).container {
+                ContainerId::ImplId(it) => it,
+                _ => return None,
+            };
+            let self_ty = self.db.impl_ty(impl_id).self_type().clone();
+            let self_ty_substs = self_ty.substs()?;
             let actual_substs = actual_def_ty.substs()?;
 
             let mut new_substs = vec![Ty::Unknown; gen.count_parent_params()];
 
             // The following code *link up* the function actual parma type
             // and impl_block type param index
-            impl_block_substs.iter().zip(actual_substs.iter()).for_each(|(param, pty)| {
+            self_ty_substs.iter().zip(actual_substs.iter()).for_each(|(param, pty)| {
                 if let Ty::Param { idx, .. } = param {
                     if let Some(s) = new_substs.get_mut(*idx as usize) {
                         *s = pty.clone();
diff --git a/crates/ra_hir/src/ty/infer/unify.rs b/crates/ra_hir_ty/src/infer/unify.rs
index 64d9394cf..f3a875678 100644
--- a/crates/ra_hir/src/ty/infer/unify.rs
+++ b/crates/ra_hir_ty/src/infer/unify.rs
@@ -1,12 +1,10 @@
 //! Unification and canonicalization logic.
 
 use super::{InferenceContext, Obligation};
-use crate::db::HirDatabase;
-use crate::ty::{
-    Canonical, InEnvironment, InferTy, ProjectionPredicate, ProjectionTy, Substs, TraitRef, Ty,
-    TypeWalk,
+use crate::{
+    db::HirDatabase, utils::make_mut_slice, Canonical, InEnvironment, InferTy, ProjectionPredicate,
+    ProjectionTy, Substs, TraitRef, Ty, TypeWalk,
 };
-use crate::util::make_mut_slice;
 
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     pub(super) fn canonicalizer<'b>(&'b mut self) -> Canonicalizer<'a, 'b, D>
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
new file mode 100644
index 000000000..b45c8f82f
--- /dev/null
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -0,0 +1,1138 @@
+//! The type system. We currently use this to infer types for completion, hover
+//! information and various assists.
+
+macro_rules! impl_froms {
+    ($e:ident: $($v:ident $(($($sv:ident),*))?),*) => {
+        $(
+            impl From<$v> for $e {
+                fn from(it: $v) -> $e {
+                    $e::$v(it)
+                }
+            }
+            $($(
+                impl From<$sv> for $e {
+                    fn from(it: $sv) -> $e {
+                        $e::$v($v::$sv(it))
+                    }
+                }
+            )*)?
+        )*
+    }
+}
+
+mod autoderef;
+pub mod primitive;
+pub mod traits;
+pub mod method_resolution;
+mod op;
+mod lower;
+mod infer;
+pub mod display;
+pub(crate) mod utils;
+pub mod db;
+pub mod diagnostics;
+pub mod expr;
+
+#[cfg(test)]
+mod tests;
+#[cfg(test)]
+mod test_db;
+mod marks;
+
+use std::ops::Deref;
+use std::sync::Arc;
+use std::{fmt, iter, mem};
+
+use hir_def::{
+    expr::ExprId, generics::GenericParams, type_ref::Mutability, AdtId, ContainerId, DefWithBodyId,
+    GenericDefId, HasModule, Lookup, TraitId, TypeAliasId,
+};
+use hir_expand::name::Name;
+use ra_db::{impl_intern_key, salsa, CrateId};
+
+use crate::{
+    db::HirDatabase,
+    primitive::{FloatTy, IntTy, Uncertain},
+    utils::make_mut_slice,
+};
+use display::{HirDisplay, HirFormatter};
+
+pub use autoderef::autoderef;
+pub use infer::{infer_query, InferTy, InferenceResult};
+pub use lower::CallableDef;
+pub use lower::{callable_item_sig, TyDefId, ValueTyDefId};
+pub use traits::{InEnvironment, Obligation, ProjectionPredicate, TraitEnvironment};
+
+/// A type constructor or type name: this might be something like the primitive
+/// type `bool`, a struct like `Vec`, or things like function pointers or
+/// tuples.
+#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
+pub enum TypeCtor {
+    /// The primitive boolean type. Written as `bool`.
+    Bool,
+
+    /// The primitive character type; holds a Unicode scalar value
+    /// (a non-surrogate code point). Written as `char`.
+    Char,
+
+    /// A primitive integer type. For example, `i32`.
+    Int(Uncertain<IntTy>),
+
+    /// A primitive floating-point type. For example, `f64`.
+    Float(Uncertain<FloatTy>),
+
+    /// Structures, enumerations and unions.
+    Adt(AdtId),
+
+    /// The pointee of a string slice. Written as `str`.
+    Str,
+
+    /// The pointee of an array slice.  Written as `[T]`.
+    Slice,
+
+    /// An array with the given length. Written as `[T; n]`.
+    Array,
+
+    /// A raw pointer. Written as `*mut T` or `*const T`
+    RawPtr(Mutability),
+
+    /// A reference; a pointer with an associated lifetime. Written as
+    /// `&'a mut T` or `&'a T`.
+    Ref(Mutability),
+
+    /// The anonymous type of a function declaration/definition. Each
+    /// function has a unique type, which is output (for a function
+    /// named `foo` returning an `i32`) as `fn() -> i32 {foo}`.
+    ///
+    /// This includes tuple struct / enum variant constructors as well.
+    ///
+    /// For example the type of `bar` here:
+    ///
+    /// ```
+    /// fn foo() -> i32 { 1 }
+    /// let bar = foo; // bar: fn() -> i32 {foo}
+    /// ```
+    FnDef(CallableDef),
+
+    /// A pointer to a function.  Written as `fn() -> i32`.
+    ///
+    /// For example the type of `bar` here:
+    ///
+    /// ```
+    /// fn foo() -> i32 { 1 }
+    /// let bar: fn() -> i32 = foo;
+    /// ```
+    FnPtr { num_args: u16 },
+
+    /// The never type `!`.
+    Never,
+
+    /// A tuple type.  For example, `(i32, bool)`.
+    Tuple { cardinality: u16 },
+
+    /// Represents an associated item like `Iterator::Item`.  This is used
+    /// when we have tried to normalize a projection like `T::Item` but
+    /// couldn't find a better representation.  In that case, we generate
+    /// an **application type** like `(Iterator::Item)<T>`.
+    AssociatedType(TypeAliasId),
+
+    /// The type of a specific closure.
+    ///
+    /// The closure signature is stored in a `FnPtr` type in the first type
+    /// parameter.
+    Closure { def: DefWithBodyId, expr: ExprId },
+}
+
+/// This exists just for Chalk, because Chalk just has a single `StructId` where
+/// we have different kinds of ADTs, primitive types and special type
+/// constructors like tuples and function pointers.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct TypeCtorId(salsa::InternId);
+impl_intern_key!(TypeCtorId);
+
+impl TypeCtor {
+    pub fn num_ty_params(self, db: &impl HirDatabase) -> usize {
+        match self {
+            TypeCtor::Bool
+            | TypeCtor::Char
+            | TypeCtor::Int(_)
+            | TypeCtor::Float(_)
+            | TypeCtor::Str
+            | TypeCtor::Never => 0,
+            TypeCtor::Slice
+            | TypeCtor::Array
+            | TypeCtor::RawPtr(_)
+            | TypeCtor::Ref(_)
+            | TypeCtor::Closure { .. } // 1 param representing the signature of the closure
+            => 1,
+            TypeCtor::Adt(adt) => {
+                let generic_params = db.generic_params(AdtId::from(adt).into());
+                generic_params.count_params_including_parent()
+            }
+            TypeCtor::FnDef(callable) => {
+                let generic_params = db.generic_params(callable.into());
+                generic_params.count_params_including_parent()
+            }
+            TypeCtor::AssociatedType(type_alias) => {
+                let generic_params = db.generic_params(type_alias.into());
+                generic_params.count_params_including_parent()
+            }
+            TypeCtor::FnPtr { num_args } => num_args as usize + 1,
+            TypeCtor::Tuple { cardinality } => cardinality as usize,
+        }
+    }
+
+    pub fn krate(self, db: &impl HirDatabase) -> Option<CrateId> {
+        match self {
+            TypeCtor::Bool
+            | TypeCtor::Char
+            | TypeCtor::Int(_)
+            | TypeCtor::Float(_)
+            | TypeCtor::Str
+            | TypeCtor::Never
+            | TypeCtor::Slice
+            | TypeCtor::Array
+            | TypeCtor::RawPtr(_)
+            | TypeCtor::Ref(_)
+            | TypeCtor::FnPtr { .. }
+            | TypeCtor::Tuple { .. } => None,
+            // Closure's krate is irrelevant for coherence I would think?
+            TypeCtor::Closure { .. } => None,
+            TypeCtor::Adt(adt) => Some(adt.module(db).krate),
+            TypeCtor::FnDef(callable) => Some(callable.krate(db)),
+            TypeCtor::AssociatedType(type_alias) => Some(type_alias.lookup(db).module(db).krate),
+        }
+    }
+
+    pub fn as_generic_def(self) -> Option<GenericDefId> {
+        match self {
+            TypeCtor::Bool
+            | TypeCtor::Char
+            | TypeCtor::Int(_)
+            | TypeCtor::Float(_)
+            | TypeCtor::Str
+            | TypeCtor::Never
+            | TypeCtor::Slice
+            | TypeCtor::Array
+            | TypeCtor::RawPtr(_)
+            | TypeCtor::Ref(_)
+            | TypeCtor::FnPtr { .. }
+            | TypeCtor::Tuple { .. }
+            | TypeCtor::Closure { .. } => None,
+            TypeCtor::Adt(adt) => Some(adt.into()),
+            TypeCtor::FnDef(callable) => Some(callable.into()),
+            TypeCtor::AssociatedType(type_alias) => Some(type_alias.into()),
+        }
+    }
+}
+
+/// A nominal type with (maybe 0) type parameters. This might be a primitive
+/// type like `bool`, a struct, tuple, function pointer, reference or
+/// several other things.
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub struct ApplicationTy {
+    pub ctor: TypeCtor,
+    pub parameters: Substs,
+}
+
+/// A "projection" type corresponds to an (unnormalized)
+/// projection like `<P0 as Trait<P1..Pn>>::Foo`. Note that the
+/// trait and all its parameters are fully known.
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub struct ProjectionTy {
+    pub associated_ty: TypeAliasId,
+    pub parameters: Substs,
+}
+
+impl ProjectionTy {
+    pub fn trait_ref(&self, db: &impl HirDatabase) -> TraitRef {
+        TraitRef { trait_: self.trait_(db).into(), substs: self.parameters.clone() }
+    }
+
+    fn trait_(&self, db: &impl HirDatabase) -> TraitId {
+        match self.associated_ty.lookup(db).container {
+            ContainerId::TraitId(it) => it,
+            _ => panic!("projection ty without parent trait"),
+        }
+    }
+}
+
+impl TypeWalk for ProjectionTy {
+    fn walk(&self, f: &mut impl FnMut(&Ty)) {
+        self.parameters.walk(f);
+    }
+
+    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
+        self.parameters.walk_mut_binders(f, binders);
+    }
+}
+
+/// A type.
+///
+/// See also the `TyKind` enum in rustc (librustc/ty/sty.rs), which represents
+/// the same thing (but in a different way).
+///
+/// This should be cheap to clone.
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub enum Ty {
+    /// A nominal type with (maybe 0) type parameters. This might be a primitive
+    /// type like `bool`, a struct, tuple, function pointer, reference or
+    /// several other things.
+    Apply(ApplicationTy),
+
+    /// A "projection" type corresponds to an (unnormalized)
+    /// projection like `<P0 as Trait<P1..Pn>>::Foo`. Note that the
+    /// trait and all its parameters are fully known.
+    Projection(ProjectionTy),
+
+    /// A type parameter; for example, `T` in `fn f<T>(x: T) {}
+    Param {
+        /// The index of the parameter (starting with parameters from the
+        /// surrounding impl, then the current function).
+        idx: u32,
+        /// The name of the parameter, for displaying.
+        // FIXME get rid of this
+        name: Name,
+    },
+
+    /// A bound type variable. Used during trait resolution to represent Chalk
+    /// variables, and in `Dyn` and `Opaque` bounds to represent the `Self` type.
+    Bound(u32),
+
+    /// A type variable used during type checking. Not to be confused with a
+    /// type parameter.
+    Infer(InferTy),
+
+    /// A trait object (`dyn Trait` or bare `Trait` in pre-2018 Rust).
+    ///
+    /// The predicates are quantified over the `Self` type, i.e. `Ty::Bound(0)`
+    /// represents the `Self` type inside the bounds. This is currently
+    /// implicit; Chalk has the `Binders` struct to make it explicit, but it
+    /// didn't seem worth the overhead yet.
+    Dyn(Arc<[GenericPredicate]>),
+
+    /// An opaque type (`impl Trait`).
+    ///
+    /// The predicates are quantified over the `Self` type; see `Ty::Dyn` for
+    /// more.
+    Opaque(Arc<[GenericPredicate]>),
+
+    /// A placeholder for a type which could not be computed; this is propagated
+    /// to avoid useless error messages. Doubles as a placeholder where type
+    /// variables are inserted before type checking, since we want to try to
+    /// infer a better type here anyway -- for the IDE use case, we want to try
+    /// to infer as much as possible even in the presence of type errors.
+    Unknown,
+}
+
+/// A list of substitutions for generic parameters.
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub struct Substs(Arc<[Ty]>);
+
+impl TypeWalk for Substs {
+    fn walk(&self, f: &mut impl FnMut(&Ty)) {
+        for t in self.0.iter() {
+            t.walk(f);
+        }
+    }
+
+    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
+        for t in make_mut_slice(&mut self.0) {
+            t.walk_mut_binders(f, binders);
+        }
+    }
+}
+
+impl Substs {
+    pub fn empty() -> Substs {
+        Substs(Arc::new([]))
+    }
+
+    pub fn single(ty: Ty) -> Substs {
+        Substs(Arc::new([ty]))
+    }
+
+    pub fn prefix(&self, n: usize) -> Substs {
+        Substs(self.0[..std::cmp::min(self.0.len(), n)].into())
+    }
+
+    pub fn as_single(&self) -> &Ty {
+        if self.0.len() != 1 {
+            panic!("expected substs of len 1, got {:?}", self);
+        }
+        &self.0[0]
+    }
+
+    /// Return Substs that replace each parameter by itself (i.e. `Ty::Param`).
+    pub fn identity(generic_params: &GenericParams) -> Substs {
+        Substs(
+            generic_params
+                .params_including_parent()
+                .into_iter()
+                .map(|p| Ty::Param { idx: p.idx, name: p.name.clone() })
+                .collect(),
+        )
+    }
+
+    /// Return Substs that replace each parameter by a bound variable.
+    pub fn bound_vars(generic_params: &GenericParams) -> Substs {
+        Substs(
+            generic_params
+                .params_including_parent()
+                .into_iter()
+                .map(|p| Ty::Bound(p.idx))
+                .collect(),
+        )
+    }
+
+    pub fn build_for_def(db: &impl HirDatabase, def: impl Into<GenericDefId>) -> SubstsBuilder {
+        let def = def.into();
+        let params = db.generic_params(def);
+        let param_count = params.count_params_including_parent();
+        Substs::builder(param_count)
+    }
+
+    pub fn build_for_generics(generic_params: &GenericParams) -> SubstsBuilder {
+        Substs::builder(generic_params.count_params_including_parent())
+    }
+
+    pub fn build_for_type_ctor(db: &impl HirDatabase, type_ctor: TypeCtor) -> SubstsBuilder {
+        Substs::builder(type_ctor.num_ty_params(db))
+    }
+
+    fn builder(param_count: usize) -> SubstsBuilder {
+        SubstsBuilder { vec: Vec::with_capacity(param_count), param_count }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct SubstsBuilder {
+    vec: Vec<Ty>,
+    param_count: usize,
+}
+
+impl SubstsBuilder {
+    pub fn build(self) -> Substs {
+        assert_eq!(self.vec.len(), self.param_count);
+        Substs(self.vec.into())
+    }
+
+    pub fn push(mut self, ty: Ty) -> Self {
+        self.vec.push(ty);
+        self
+    }
+
+    fn remaining(&self) -> usize {
+        self.param_count - self.vec.len()
+    }
+
+    pub fn fill_with_bound_vars(self, starting_from: u32) -> Self {
+        self.fill((starting_from..).map(Ty::Bound))
+    }
+
+    pub fn fill_with_params(self) -> Self {
+        let start = self.vec.len() as u32;
+        self.fill((start..).map(|idx| Ty::Param { idx, name: Name::missing() }))
+    }
+
+    pub fn fill_with_unknown(self) -> Self {
+        self.fill(iter::repeat(Ty::Unknown))
+    }
+
+    pub fn fill(mut self, filler: impl Iterator<Item = Ty>) -> Self {
+        self.vec.extend(filler.take(self.remaining()));
+        assert_eq!(self.remaining(), 0);
+        self
+    }
+
+    pub fn use_parent_substs(mut self, parent_substs: &Substs) -> Self {
+        assert!(self.vec.is_empty());
+        assert!(parent_substs.len() <= self.param_count);
+        self.vec.extend(parent_substs.iter().cloned());
+        self
+    }
+}
+
+impl Deref for Substs {
+    type Target = [Ty];
+
+    fn deref(&self) -> &[Ty] {
+        &self.0
+    }
+}
+
+/// A trait with type parameters. This includes the `Self`, so this represents a concrete type implementing the trait.
+/// Name to be bikeshedded: TraitBound? TraitImplements?
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub struct TraitRef {
+    /// FIXME name?
+    pub trait_: TraitId,
+    pub substs: Substs,
+}
+
+impl TraitRef {
+    pub fn self_ty(&self) -> &Ty {
+        &self.substs[0]
+    }
+}
+
+impl TypeWalk for TraitRef {
+    fn walk(&self, f: &mut impl FnMut(&Ty)) {
+        self.substs.walk(f);
+    }
+
+    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
+        self.substs.walk_mut_binders(f, binders);
+    }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum ImplTy {
+    Inherent(Ty),
+    TraitRef(TraitRef),
+}
+
+impl ImplTy {
+    pub(crate) fn self_type(&self) -> &Ty {
+        match self {
+            ImplTy::Inherent(it) => it,
+            ImplTy::TraitRef(tr) => &tr.substs[0],
+        }
+    }
+}
+
+/// Like `generics::WherePredicate`, but with resolved types: A condition on the
+/// parameters of a generic item.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum GenericPredicate {
+    /// The given trait needs to be implemented for its type parameters.
+    Implemented(TraitRef),
+    /// An associated type bindings like in `Iterator<Item = T>`.
+    Projection(ProjectionPredicate),
+    /// We couldn't resolve the trait reference. (If some type parameters can't
+    /// be resolved, they will just be Unknown).
+    Error,
+}
+
+impl GenericPredicate {
+    pub fn is_error(&self) -> bool {
+        match self {
+            GenericPredicate::Error => true,
+            _ => false,
+        }
+    }
+
+    pub fn is_implemented(&self) -> bool {
+        match self {
+            GenericPredicate::Implemented(_) => true,
+            _ => false,
+        }
+    }
+
+    pub fn trait_ref(&self, db: &impl HirDatabase) -> Option<TraitRef> {
+        match self {
+            GenericPredicate::Implemented(tr) => Some(tr.clone()),
+            GenericPredicate::Projection(proj) => Some(proj.projection_ty.trait_ref(db)),
+            GenericPredicate::Error => None,
+        }
+    }
+}
+
+impl TypeWalk for GenericPredicate {
+    fn walk(&self, f: &mut impl FnMut(&Ty)) {
+        match self {
+            GenericPredicate::Implemented(trait_ref) => trait_ref.walk(f),
+            GenericPredicate::Projection(projection_pred) => projection_pred.walk(f),
+            GenericPredicate::Error => {}
+        }
+    }
+
+    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
+        match self {
+            GenericPredicate::Implemented(trait_ref) => trait_ref.walk_mut_binders(f, binders),
+            GenericPredicate::Projection(projection_pred) => {
+                projection_pred.walk_mut_binders(f, binders)
+            }
+            GenericPredicate::Error => {}
+        }
+    }
+}
+
+/// Basically a claim (currently not validated / checked) that the contained
+/// type / trait ref contains no inference variables; any inference variables it
+/// contained have been replaced by bound variables, and `num_vars` tells us how
+/// many there are. This is used to erase irrelevant differences between types
+/// before using them in queries.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct Canonical<T> {
+    pub value: T,
+    pub num_vars: usize,
+}
+
+/// A function signature as seen by type inference: Several parameter types and
+/// one return type.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct FnSig {
+    params_and_return: Arc<[Ty]>,
+}
+
+impl FnSig {
+    pub fn from_params_and_return(mut params: Vec<Ty>, ret: Ty) -> FnSig {
+        params.push(ret);
+        FnSig { params_and_return: params.into() }
+    }
+
+    pub fn from_fn_ptr_substs(substs: &Substs) -> FnSig {
+        FnSig { params_and_return: Arc::clone(&substs.0) }
+    }
+
+    pub fn params(&self) -> &[Ty] {
+        &self.params_and_return[0..self.params_and_return.len() - 1]
+    }
+
+    pub fn ret(&self) -> &Ty {
+        &self.params_and_return[self.params_and_return.len() - 1]
+    }
+}
+
+impl TypeWalk for FnSig {
+    fn walk(&self, f: &mut impl FnMut(&Ty)) {
+        for t in self.params_and_return.iter() {
+            t.walk(f);
+        }
+    }
+
+    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
+        for t in make_mut_slice(&mut self.params_and_return) {
+            t.walk_mut_binders(f, binders);
+        }
+    }
+}
+
+impl Ty {
+    pub fn simple(ctor: TypeCtor) -> Ty {
+        Ty::Apply(ApplicationTy { ctor, parameters: Substs::empty() })
+    }
+    pub fn apply_one(ctor: TypeCtor, param: Ty) -> Ty {
+        Ty::Apply(ApplicationTy { ctor, parameters: Substs::single(param) })
+    }
+    pub fn apply(ctor: TypeCtor, parameters: Substs) -> Ty {
+        Ty::Apply(ApplicationTy { ctor, parameters })
+    }
+    pub fn unit() -> Self {
+        Ty::apply(TypeCtor::Tuple { cardinality: 0 }, Substs::empty())
+    }
+
+    pub fn as_reference(&self) -> Option<(&Ty, Mutability)> {
+        match self {
+            Ty::Apply(ApplicationTy { ctor: TypeCtor::Ref(mutability), parameters }) => {
+                Some((parameters.as_single(), *mutability))
+            }
+            _ => None,
+        }
+    }
+
+    pub fn as_adt(&self) -> Option<(AdtId, &Substs)> {
+        match self {
+            Ty::Apply(ApplicationTy { ctor: TypeCtor::Adt(adt_def), parameters }) => {
+                Some((*adt_def, parameters))
+            }
+            _ => None,
+        }
+    }
+
+    pub fn as_tuple(&self) -> Option<&Substs> {
+        match self {
+            Ty::Apply(ApplicationTy { ctor: TypeCtor::Tuple { .. }, parameters }) => {
+                Some(parameters)
+            }
+            _ => None,
+        }
+    }
+
+    pub fn as_callable(&self) -> Option<(CallableDef, &Substs)> {
+        match self {
+            Ty::Apply(ApplicationTy { ctor: TypeCtor::FnDef(callable_def), parameters }) => {
+                Some((*callable_def, parameters))
+            }
+            _ => None,
+        }
+    }
+
+    fn builtin_deref(&self) -> Option<Ty> {
+        match self {
+            Ty::Apply(a_ty) => match a_ty.ctor {
+                TypeCtor::Ref(..) => Some(Ty::clone(a_ty.parameters.as_single())),
+                TypeCtor::RawPtr(..) => Some(Ty::clone(a_ty.parameters.as_single())),
+                _ => None,
+            },
+            _ => None,
+        }
+    }
+
+    fn callable_sig(&self, db: &impl HirDatabase) -> Option<FnSig> {
+        match self {
+            Ty::Apply(a_ty) => match a_ty.ctor {
+                TypeCtor::FnPtr { .. } => Some(FnSig::from_fn_ptr_substs(&a_ty.parameters)),
+                TypeCtor::FnDef(def) => {
+                    let sig = db.callable_item_signature(def);
+                    Some(sig.subst(&a_ty.parameters))
+                }
+                TypeCtor::Closure { .. } => {
+                    let sig_param = &a_ty.parameters[0];
+                    sig_param.callable_sig(db)
+                }
+                _ => None,
+            },
+            _ => None,
+        }
+    }
+
+    /// If this is a type with type parameters (an ADT or function), replaces
+    /// the `Substs` for these type parameters with the given ones. (So e.g. if
+    /// `self` is `Option<_>` and the substs contain `u32`, we'll have
+    /// `Option<u32>` afterwards.)
+    pub fn apply_substs(self, substs: Substs) -> Ty {
+        match self {
+            Ty::Apply(ApplicationTy { ctor, parameters: previous_substs }) => {
+                assert_eq!(previous_substs.len(), substs.len());
+                Ty::Apply(ApplicationTy { ctor, parameters: substs })
+            }
+            _ => self,
+        }
+    }
+
+    /// Returns the type parameters of this type if it has some (i.e. is an ADT
+    /// or function); so if `self` is `Option<u32>`, this returns the `u32`.
+    pub fn substs(&self) -> Option<Substs> {
+        match self {
+            Ty::Apply(ApplicationTy { parameters, .. }) => Some(parameters.clone()),
+            _ => None,
+        }
+    }
+
+    /// If this is an `impl Trait` or `dyn Trait`, returns that trait.
+    pub fn inherent_trait(&self) -> Option<TraitId> {
+        match self {
+            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
+                predicates.iter().find_map(|pred| match pred {
+                    GenericPredicate::Implemented(tr) => Some(tr.trait_),
+                    _ => None,
+                })
+            }
+            _ => None,
+        }
+    }
+}
+
+/// This allows walking structures that contain types to do something with those
+/// types, similar to Chalk's `Fold` trait.
+pub trait TypeWalk {
+    fn walk(&self, f: &mut impl FnMut(&Ty));
+    fn walk_mut(&mut self, f: &mut impl FnMut(&mut Ty)) {
+        self.walk_mut_binders(&mut |ty, _binders| f(ty), 0);
+    }
+    /// Walk the type, counting entered binders.
+    ///
+    /// `Ty::Bound` variables use DeBruijn indexing, which means that 0 refers
+    /// to the innermost binder, 1 to the next, etc.. So when we want to
+    /// substitute a certain bound variable, we can't just walk the whole type
+    /// and blindly replace each instance of a certain index; when we 'enter'
+    /// things that introduce new bound variables, we have to keep track of
+    /// that. Currently, the only thing that introduces bound variables on our
+    /// side are `Ty::Dyn` and `Ty::Opaque`, which each introduce a bound
+    /// variable for the self type.
+    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize);
+
+    fn fold(mut self, f: &mut impl FnMut(Ty) -> Ty) -> Self
+    where
+        Self: Sized,
+    {
+        self.walk_mut(&mut |ty_mut| {
+            let ty = mem::replace(ty_mut, Ty::Unknown);
+            *ty_mut = f(ty);
+        });
+        self
+    }
+
+    /// Replaces type parameters in this type using the given `Substs`. (So e.g.
+    /// if `self` is `&[T]`, where type parameter T has index 0, and the
+    /// `Substs` contain `u32` at index 0, we'll have `&[u32]` afterwards.)
+    fn subst(self, substs: &Substs) -> Self
+    where
+        Self: Sized,
+    {
+        self.fold(&mut |ty| match ty {
+            Ty::Param { idx, name } => {
+                substs.get(idx as usize).cloned().unwrap_or(Ty::Param { idx, name })
+            }
+            ty => ty,
+        })
+    }
+
+    /// Substitutes `Ty::Bound` vars (as opposed to type parameters).
+    fn subst_bound_vars(mut self, substs: &Substs) -> Self
+    where
+        Self: Sized,
+    {
+        self.walk_mut_binders(
+            &mut |ty, binders| match ty {
+                &mut Ty::Bound(idx) => {
+                    if idx as usize >= binders && (idx as usize - binders) < substs.len() {
+                        *ty = substs.0[idx as usize - binders].clone();
+                    }
+                }
+                _ => {}
+            },
+            0,
+        );
+        self
+    }
+
+    /// Shifts up `Ty::Bound` vars by `n`.
+    fn shift_bound_vars(self, n: i32) -> Self
+    where
+        Self: Sized,
+    {
+        self.fold(&mut |ty| match ty {
+            Ty::Bound(idx) => {
+                assert!(idx as i32 >= -n);
+                Ty::Bound((idx as i32 + n) as u32)
+            }
+            ty => ty,
+        })
+    }
+}
+
+impl TypeWalk for Ty {
+    fn walk(&self, f: &mut impl FnMut(&Ty)) {
+        match self {
+            Ty::Apply(a_ty) => {
+                for t in a_ty.parameters.iter() {
+                    t.walk(f);
+                }
+            }
+            Ty::Projection(p_ty) => {
+                for t in p_ty.parameters.iter() {
+                    t.walk(f);
+                }
+            }
+            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
+                for p in predicates.iter() {
+                    p.walk(f);
+                }
+            }
+            Ty::Param { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
+        }
+        f(self);
+    }
+
+    fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
+        match self {
+            Ty::Apply(a_ty) => {
+                a_ty.parameters.walk_mut_binders(f, binders);
+            }
+            Ty::Projection(p_ty) => {
+                p_ty.parameters.walk_mut_binders(f, binders);
+            }
+            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
+                for p in make_mut_slice(predicates) {
+                    p.walk_mut_binders(f, binders + 1);
+                }
+            }
+            Ty::Param { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
+        }
+        f(self, binders);
+    }
+}
+
+impl HirDisplay for &Ty {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        HirDisplay::hir_fmt(*self, f)
+    }
+}
+
+impl HirDisplay for ApplicationTy {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        if f.should_truncate() {
+            return write!(f, "…");
+        }
+
+        match self.ctor {
+            TypeCtor::Bool => write!(f, "bool")?,
+            TypeCtor::Char => write!(f, "char")?,
+            TypeCtor::Int(t) => write!(f, "{}", t)?,
+            TypeCtor::Float(t) => write!(f, "{}", t)?,
+            TypeCtor::Str => write!(f, "str")?,
+            TypeCtor::Slice => {
+                let t = self.parameters.as_single();
+                write!(f, "[{}]", t.display(f.db))?;
+            }
+            TypeCtor::Array => {
+                let t = self.parameters.as_single();
+                write!(f, "[{};_]", t.display(f.db))?;
+            }
+            TypeCtor::RawPtr(m) => {
+                let t = self.parameters.as_single();
+                write!(f, "*{}{}", m.as_keyword_for_ptr(), t.display(f.db))?;
+            }
+            TypeCtor::Ref(m) => {
+                let t = self.parameters.as_single();
+                write!(f, "&{}{}", m.as_keyword_for_ref(), t.display(f.db))?;
+            }
+            TypeCtor::Never => write!(f, "!")?,
+            TypeCtor::Tuple { .. } => {
+                let ts = &self.parameters;
+                if ts.len() == 1 {
+                    write!(f, "({},)", ts[0].display(f.db))?;
+                } else {
+                    write!(f, "(")?;
+                    f.write_joined(&*ts.0, ", ")?;
+                    write!(f, ")")?;
+                }
+            }
+            TypeCtor::FnPtr { .. } => {
+                let sig = FnSig::from_fn_ptr_substs(&self.parameters);
+                write!(f, "fn(")?;
+                f.write_joined(sig.params(), ", ")?;
+                write!(f, ") -> {}", sig.ret().display(f.db))?;
+            }
+            TypeCtor::FnDef(def) => {
+                let sig = f.db.callable_item_signature(def);
+                let name = match def {
+                    CallableDef::FunctionId(ff) => f.db.function_data(ff).name.clone(),
+                    CallableDef::StructId(s) => f.db.struct_data(s).name.clone(),
+                    CallableDef::EnumVariantId(e) => {
+                        let enum_data = f.db.enum_data(e.parent);
+                        enum_data.variants[e.local_id].name.clone()
+                    }
+                };
+                match def {
+                    CallableDef::FunctionId(_) => write!(f, "fn {}", name)?,
+                    CallableDef::StructId(_) | CallableDef::EnumVariantId(_) => {
+                        write!(f, "{}", name)?
+                    }
+                }
+                if self.parameters.len() > 0 {
+                    write!(f, "<")?;
+                    f.write_joined(&*self.parameters.0, ", ")?;
+                    write!(f, ">")?;
+                }
+                write!(f, "(")?;
+                f.write_joined(sig.params(), ", ")?;
+                write!(f, ") -> {}", sig.ret().display(f.db))?;
+            }
+            TypeCtor::Adt(def_id) => {
+                let name = match def_id {
+                    AdtId::StructId(it) => f.db.struct_data(it).name.clone(),
+                    AdtId::UnionId(it) => f.db.union_data(it).name.clone(),
+                    AdtId::EnumId(it) => f.db.enum_data(it).name.clone(),
+                };
+                write!(f, "{}", name)?;
+                if self.parameters.len() > 0 {
+                    write!(f, "<")?;
+                    f.write_joined(&*self.parameters.0, ", ")?;
+                    write!(f, ">")?;
+                }
+            }
+            TypeCtor::AssociatedType(type_alias) => {
+                let trait_ = match type_alias.lookup(f.db).container {
+                    ContainerId::TraitId(it) => it,
+                    _ => panic!("not an associated type"),
+                };
+                let trait_name = f.db.trait_data(trait_).name.clone();
+                let name = f.db.type_alias_data(type_alias).name.clone();
+                write!(f, "{}::{}", trait_name, name)?;
+                if self.parameters.len() > 0 {
+                    write!(f, "<")?;
+                    f.write_joined(&*self.parameters.0, ", ")?;
+                    write!(f, ">")?;
+                }
+            }
+            TypeCtor::Closure { .. } => {
+                let sig = self.parameters[0]
+                    .callable_sig(f.db)
+                    .expect("first closure parameter should contain signature");
+                write!(f, "|")?;
+                f.write_joined(sig.params(), ", ")?;
+                write!(f, "| -> {}", sig.ret().display(f.db))?;
+            }
+        }
+        Ok(())
+    }
+}
+
+impl HirDisplay for ProjectionTy {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        if f.should_truncate() {
+            return write!(f, "…");
+        }
+
+        let trait_name = f.db.trait_data(self.trait_(f.db)).name.clone();
+        write!(f, "<{} as {}", self.parameters[0].display(f.db), trait_name,)?;
+        if self.parameters.len() > 1 {
+            write!(f, "<")?;
+            f.write_joined(&self.parameters[1..], ", ")?;
+            write!(f, ">")?;
+        }
+        write!(f, ">::{}", f.db.type_alias_data(self.associated_ty).name)?;
+        Ok(())
+    }
+}
+
+impl HirDisplay for Ty {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        if f.should_truncate() {
+            return write!(f, "…");
+        }
+
+        match self {
+            Ty::Apply(a_ty) => a_ty.hir_fmt(f)?,
+            Ty::Projection(p_ty) => p_ty.hir_fmt(f)?,
+            Ty::Param { name, .. } => write!(f, "{}", name)?,
+            Ty::Bound(idx) => write!(f, "?{}", idx)?,
+            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
+                match self {
+                    Ty::Dyn(_) => write!(f, "dyn ")?,
+                    Ty::Opaque(_) => write!(f, "impl ")?,
+                    _ => unreachable!(),
+                };
+                // Note: This code is written to produce nice results (i.e.
+                // corresponding to surface Rust) for types that can occur in
+                // actual Rust. It will have weird results if the predicates
+                // aren't as expected (i.e. self types = $0, projection
+                // predicates for a certain trait come after the Implemented
+                // predicate for that trait).
+                let mut first = true;
+                let mut angle_open = false;
+                for p in predicates.iter() {
+                    match p {
+                        GenericPredicate::Implemented(trait_ref) => {
+                            if angle_open {
+                                write!(f, ">")?;
+                            }
+                            if !first {
+                                write!(f, " + ")?;
+                            }
+                            // We assume that the self type is $0 (i.e. the
+                            // existential) here, which is the only thing that's
+                            // possible in actual Rust, and hence don't print it
+                            write!(f, "{}", f.db.trait_data(trait_ref.trait_).name.clone())?;
+                            if trait_ref.substs.len() > 1 {
+                                write!(f, "<")?;
+                                f.write_joined(&trait_ref.substs[1..], ", ")?;
+                                // there might be assoc type bindings, so we leave the angle brackets open
+                                angle_open = true;
+                            }
+                        }
+                        GenericPredicate::Projection(projection_pred) => {
+                            // in types in actual Rust, these will always come
+                            // after the corresponding Implemented predicate
+                            if angle_open {
+                                write!(f, ", ")?;
+                            } else {
+                                write!(f, "<")?;
+                                angle_open = true;
+                            }
+                            let name =
+                                f.db.type_alias_data(projection_pred.projection_ty.associated_ty)
+                                    .name
+                                    .clone();
+                            write!(f, "{} = ", name)?;
+                            projection_pred.ty.hir_fmt(f)?;
+                        }
+                        GenericPredicate::Error => {
+                            if angle_open {
+                                // impl Trait<X, {error}>
+                                write!(f, ", ")?;
+                            } else if !first {
+                                // impl Trait + {error}
+                                write!(f, " + ")?;
+                            }
+                            p.hir_fmt(f)?;
+                        }
+                    }
+                    first = false;
+                }
+                if angle_open {
+                    write!(f, ">")?;
+                }
+            }
+            Ty::Unknown => write!(f, "{{unknown}}")?,
+            Ty::Infer(..) => write!(f, "_")?,
+        }
+        Ok(())
+    }
+}
+
+impl TraitRef {
+    fn hir_fmt_ext(&self, f: &mut HirFormatter<impl HirDatabase>, use_as: bool) -> fmt::Result {
+        if f.should_truncate() {
+            return write!(f, "…");
+        }
+
+        self.substs[0].hir_fmt(f)?;
+        if use_as {
+            write!(f, " as ")?;
+        } else {
+            write!(f, ": ")?;
+        }
+        write!(f, "{}", f.db.trait_data(self.trait_).name.clone())?;
+        if self.substs.len() > 1 {
+            write!(f, "<")?;
+            f.write_joined(&self.substs[1..], ", ")?;
+            write!(f, ">")?;
+        }
+        Ok(())
+    }
+}
+
+impl HirDisplay for TraitRef {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        self.hir_fmt_ext(f, false)
+    }
+}
+
+impl HirDisplay for &GenericPredicate {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        HirDisplay::hir_fmt(*self, f)
+    }
+}
+
+impl HirDisplay for GenericPredicate {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        if f.should_truncate() {
+            return write!(f, "…");
+        }
+
+        match self {
+            GenericPredicate::Implemented(trait_ref) => trait_ref.hir_fmt(f)?,
+            GenericPredicate::Projection(projection_pred) => {
+                write!(f, "<")?;
+                projection_pred.projection_ty.trait_ref(f.db).hir_fmt_ext(f, true)?;
+                write!(
+                    f,
+                    ">::{} = {}",
+                    f.db.type_alias_data(projection_pred.projection_ty.associated_ty).name,
+                    projection_pred.ty.display(f.db)
+                )?;
+            }
+            GenericPredicate::Error => write!(f, "{{error}}")?,
+        }
+        Ok(())
+    }
+}
+
+impl HirDisplay for Obligation {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        match self {
+            Obligation::Trait(tr) => write!(f, "Implements({})", tr.display(f.db)),
+            Obligation::Projection(proj) => write!(
+                f,
+                "Normalize({} => {})",
+                proj.projection_ty.display(f.db),
+                proj.ty.display(f.db)
+            ),
+        }
+    }
+}
diff --git a/crates/ra_hir/src/ty/lower.rs b/crates/ra_hir_ty/src/lower.rs
index a39beb2a0..091c60f4f 100644
--- a/crates/ra_hir/src/ty/lower.rs
+++ b/crates/ra_hir_ty/src/lower.rs
@@ -9,43 +9,30 @@ use std::iter;
 use std::sync::Arc;
 
 use hir_def::{
-    builtin_type::{BuiltinFloat, BuiltinInt, BuiltinType},
+    builtin_type::BuiltinType,
     generics::WherePredicate,
-    path::{GenericArg, PathSegment},
+    path::{GenericArg, Path, PathKind, PathSegment},
     resolver::{HasResolver, Resolver, TypeNs},
     type_ref::{TypeBound, TypeRef},
-    AdtId, GenericDefId, LocalStructFieldId, VariantId,
+    AdtId, AstItemDef, ConstId, EnumId, EnumVariantId, FunctionId, GenericDefId, HasModule, ImplId,
+    LocalStructFieldId, Lookup, StaticId, StructId, TraitId, TypeAliasId, UnionId, VariantId,
 };
 use ra_arena::map::ArenaMap;
+use ra_db::CrateId;
 
-use super::{
-    FnSig, GenericPredicate, ProjectionPredicate, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
-    TypeWalk,
-};
 use crate::{
     db::HirDatabase,
-    ty::{
-        primitive::{FloatTy, IntTy, Uncertain},
-        Adt,
+    primitive::{FloatTy, IntTy},
+    utils::{
+        all_super_traits, associated_type_by_name_including_super_traits, make_mut_slice,
+        variant_data,
     },
-    util::make_mut_slice,
-    Const, Enum, EnumVariant, Function, GenericDef, ImplBlock, ModuleDef, Path, Static, Struct,
-    Trait, TypeAlias, Union,
+    FnSig, GenericPredicate, ImplTy, ProjectionPredicate, ProjectionTy, Substs, TraitEnvironment,
+    TraitRef, Ty, TypeCtor, TypeWalk,
 };
 
-// FIXME: this is only really used in `type_for_def`, which contains a bunch of
-// impossible cases. Perhaps we should recombine `TypeableDef` and `Namespace`
-// into a `AsTypeDef`, `AsValueDef` enums?
-#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub enum Namespace {
-    Types,
-    Values,
-    // Note that only type inference uses this enum, and it doesn't care about macros.
-    // Macro,
-}
-
 impl Ty {
-    pub(crate) fn from_hir(db: &impl HirDatabase, resolver: &Resolver, type_ref: &TypeRef) -> Self {
+    pub fn from_hir(db: &impl HirDatabase, resolver: &Resolver, type_ref: &TypeRef) -> Self {
         match type_ref {
             TypeRef::Never => Ty::simple(TypeCtor::Never),
             TypeRef::Tuple(inner) => {
@@ -114,7 +101,7 @@ impl Ty {
             TypeRef::Path(path) => path,
             _ => return None,
         };
-        if let crate::PathKind::Type(_) = &path.kind {
+        if let PathKind::Type(_) = &path.kind {
             return None;
         }
         if path.segments.len() > 1 {
@@ -158,19 +145,16 @@ impl Ty {
     ) -> Ty {
         let ty = match resolution {
             TypeNs::TraitId(trait_) => {
-                let trait_ref = TraitRef::from_resolved_path(
-                    db,
-                    resolver,
-                    trait_.into(),
-                    resolved_segment,
-                    None,
-                );
+                let trait_ref =
+                    TraitRef::from_resolved_path(db, resolver, trait_, resolved_segment, None);
                 return if remaining_segments.len() == 1 {
                     let segment = &remaining_segments[0];
-                    match trait_ref
-                        .trait_
-                        .associated_type_by_name_including_super_traits(db, &segment.name)
-                    {
+                    let associated_ty = associated_type_by_name_including_super_traits(
+                        db,
+                        trait_ref.trait_,
+                        &segment.name,
+                    );
+                    match associated_ty {
                         Some(associated_ty) => {
                             // FIXME handle type parameters on the segment
                             Ty::Projection(ProjectionTy {
@@ -195,8 +179,8 @@ impl Ty {
                 let name = resolved_segment.name.clone();
                 Ty::Param { idx, name }
             }
-            TypeNs::SelfType(impl_block) => ImplBlock::from(impl_block).target_ty(db),
-            TypeNs::AdtSelfType(adt) => Adt::from(adt).ty(db),
+            TypeNs::SelfType(impl_id) => db.impl_ty(impl_id).self_type().clone(),
+            TypeNs::AdtSelfType(adt) => db.ty(adt.into()),
 
             TypeNs::AdtId(it) => Ty::from_hir_path_inner(db, resolver, resolved_segment, it.into()),
             TypeNs::BuiltinType(it) => {
@@ -214,7 +198,7 @@ impl Ty {
 
     pub(crate) fn from_hir_path(db: &impl HirDatabase, resolver: &Resolver, path: &Path) -> Ty {
         // Resolve the path (in type namespace)
-        if let crate::PathKind::Type(type_ref) = &path.kind {
+        if let PathKind::Type(type_ref) = &path.kind {
             let ty = Ty::from_hir(db, resolver, &type_ref);
             let remaining_segments = &path.segments[..];
             return Ty::from_type_relative_path(db, resolver, ty, remaining_segments);
@@ -258,9 +242,9 @@ impl Ty {
             GenericPredicate::Implemented(tr) if tr.self_ty() == &self_ty => Some(tr.trait_),
             _ => None,
         });
-        let traits = traits_from_env.flat_map(|t| t.all_super_traits(db));
+        let traits = traits_from_env.flat_map(|t| all_super_traits(db, t));
         for t in traits {
-            if let Some(associated_ty) = t.associated_type_by_name(db, &segment.name) {
+            if let Some(associated_ty) = db.trait_data(t).associated_type_by_name(&segment.name) {
                 let substs =
                     Substs::build_for_def(db, t).push(self_ty.clone()).fill_with_unknown().build();
                 // FIXME handle type parameters on the segment
@@ -274,27 +258,15 @@ impl Ty {
         db: &impl HirDatabase,
         resolver: &Resolver,
         segment: &PathSegment,
-        typable: TypableDef,
+        typable: TyDefId,
     ) -> Ty {
-        let ty = db.type_for_def(typable, Namespace::Types);
-        let substs = Ty::substs_from_path_segment(db, resolver, segment, typable);
-        ty.subst(&substs)
-    }
-
-    pub(super) fn substs_from_path_segment(
-        db: &impl HirDatabase,
-        resolver: &Resolver,
-        segment: &PathSegment,
-        resolved: TypableDef,
-    ) -> Substs {
-        let def_generic: Option<GenericDef> = match resolved {
-            TypableDef::Function(func) => Some(func.into()),
-            TypableDef::Adt(adt) => Some(adt.into()),
-            TypableDef::EnumVariant(var) => Some(var.parent_enum(db).into()),
-            TypableDef::TypeAlias(t) => Some(t.into()),
-            TypableDef::Const(_) | TypableDef::Static(_) | TypableDef::BuiltinType(_) => None,
+        let generic_def = match typable {
+            TyDefId::BuiltinType(_) => None,
+            TyDefId::AdtId(it) => Some(it.into()),
+            TyDefId::TypeAliasId(it) => Some(it.into()),
         };
-        substs_from_path_segment(db, resolver, segment, def_generic, false)
+        let substs = substs_from_path_segment(db, resolver, segment, generic_def, false);
+        db.ty(typable).subst(&substs)
     }
 
     /// Collect generic arguments from a path into a `Substs`. See also
@@ -303,17 +275,18 @@ impl Ty {
         db: &impl HirDatabase,
         resolver: &Resolver,
         path: &Path,
-        resolved: TypableDef,
+        // Note that we don't call `db.value_type(resolved)` here,
+        // `ValueTyDefId` is just a convenient way to pass generics and
+        // special-case enum variants
+        resolved: ValueTyDefId,
     ) -> Substs {
         let last = path.segments.last().expect("path should have at least one segment");
-        let segment = match resolved {
-            TypableDef::Function(_)
-            | TypableDef::Adt(_)
-            | TypableDef::Const(_)
-            | TypableDef::Static(_)
-            | TypableDef::TypeAlias(_)
-            | TypableDef::BuiltinType(_) => last,
-            TypableDef::EnumVariant(_) => {
+        let (segment, generic_def) = match resolved {
+            ValueTyDefId::FunctionId(it) => (last, Some(it.into())),
+            ValueTyDefId::StructId(it) => (last, Some(it.into())),
+            ValueTyDefId::ConstId(it) => (last, Some(it.into())),
+            ValueTyDefId::StaticId(_) => (last, None),
+            ValueTyDefId::EnumVariantId(var) => {
                 // the generic args for an enum variant may be either specified
                 // on the segment referring to the enum, or on the segment
                 // referring to the variant. So `Option::<T>::None` and
@@ -327,10 +300,10 @@ impl Ty {
                     // Option::None::<T>
                     last
                 };
-                segment
+                (segment, Some(var.parent.into()))
             }
         };
-        Ty::substs_from_path_segment(db, resolver, segment, resolved)
+        substs_from_path_segment(db, resolver, segment, generic_def, false)
     }
 }
 
@@ -338,7 +311,7 @@ pub(super) fn substs_from_path_segment(
     db: &impl HirDatabase,
     resolver: &Resolver,
     segment: &PathSegment,
-    def_generic: Option<GenericDef>,
+    def_generic: Option<GenericDefId>,
     add_self_param: bool,
 ) -> Substs {
     let mut substs = Vec::new();
@@ -376,7 +349,7 @@ pub(super) fn substs_from_path_segment(
 
     // handle defaults
     if let Some(def_generic) = def_generic {
-        let default_substs = db.generic_defaults(def_generic);
+        let default_substs = db.generic_defaults(def_generic.into());
         assert_eq!(substs.len(), default_substs.len());
 
         for (i, default_ty) in default_substs.iter().enumerate() {
@@ -390,7 +363,7 @@ pub(super) fn substs_from_path_segment(
 }
 
 impl TraitRef {
-    pub(crate) fn from_path(
+    fn from_path(
         db: &impl HirDatabase,
         resolver: &Resolver,
         path: &Path,
@@ -404,10 +377,10 @@ impl TraitRef {
         Some(TraitRef::from_resolved_path(db, resolver, resolved.into(), segment, explicit_self_ty))
     }
 
-    pub(super) fn from_resolved_path(
+    pub(crate) fn from_resolved_path(
         db: &impl HirDatabase,
         resolver: &Resolver,
-        resolved: Trait,
+        resolved: TraitId,
         segment: &PathSegment,
         explicit_self_ty: Option<Ty>,
     ) -> Self {
@@ -418,7 +391,7 @@ impl TraitRef {
         TraitRef { trait_: resolved, substs }
     }
 
-    pub(crate) fn from_hir(
+    fn from_hir(
         db: &impl HirDatabase,
         resolver: &Resolver,
         type_ref: &TypeRef,
@@ -435,18 +408,13 @@ impl TraitRef {
         db: &impl HirDatabase,
         resolver: &Resolver,
         segment: &PathSegment,
-        resolved: Trait,
+        resolved: TraitId,
     ) -> Substs {
         let has_self_param =
             segment.args_and_bindings.as_ref().map(|a| a.has_self_type).unwrap_or(false);
         substs_from_path_segment(db, resolver, segment, Some(resolved.into()), !has_self_param)
     }
 
-    pub(crate) fn for_trait(db: &impl HirDatabase, trait_: Trait) -> TraitRef {
-        let substs = Substs::identity(&db.generic_params(trait_.id.into()));
-        TraitRef { trait_, substs }
-    }
-
     pub(crate) fn from_type_bound(
         db: &impl HirDatabase,
         resolver: &Resolver,
@@ -502,10 +470,11 @@ fn assoc_type_bindings_from_type_bound<'a>(
         .flat_map(|args_and_bindings| args_and_bindings.bindings.iter())
         .map(move |(name, type_ref)| {
             let associated_ty =
-                match trait_ref.trait_.associated_type_by_name_including_super_traits(db, &name) {
-                    None => return GenericPredicate::Error,
-                    Some(t) => t,
-                };
+                associated_type_by_name_including_super_traits(db, trait_ref.trait_, &name);
+            let associated_ty = match associated_ty {
+                None => return GenericPredicate::Error,
+                Some(t) => t,
+            };
             let projection_ty =
                 ProjectionTy { associated_ty, parameters: trait_ref.substs.clone() };
             let ty = Ty::from_hir(db, resolver, type_ref);
@@ -514,39 +483,12 @@ fn assoc_type_bindings_from_type_bound<'a>(
         })
 }
 
-/// Build the declared type of an item. This depends on the namespace; e.g. for
-/// `struct Foo(usize)`, we have two types: The type of the struct itself, and
-/// the constructor function `(usize) -> Foo` which lives in the values
-/// namespace.
-pub(crate) fn type_for_def(db: &impl HirDatabase, def: TypableDef, ns: Namespace) -> Ty {
-    match (def, ns) {
-        (TypableDef::Function(f), Namespace::Values) => type_for_fn(db, f),
-        (TypableDef::Adt(Adt::Struct(s)), Namespace::Values) => type_for_struct_constructor(db, s),
-        (TypableDef::Adt(adt), Namespace::Types) => type_for_adt(db, adt),
-        (TypableDef::EnumVariant(v), Namespace::Values) => type_for_enum_variant_constructor(db, v),
-        (TypableDef::TypeAlias(t), Namespace::Types) => type_for_type_alias(db, t),
-        (TypableDef::Const(c), Namespace::Values) => type_for_const(db, c),
-        (TypableDef::Static(c), Namespace::Values) => type_for_static(db, c),
-        (TypableDef::BuiltinType(t), Namespace::Types) => type_for_builtin(t),
-
-        // 'error' cases:
-        (TypableDef::Function(_), Namespace::Types) => Ty::Unknown,
-        (TypableDef::Adt(Adt::Union(_)), Namespace::Values) => Ty::Unknown,
-        (TypableDef::Adt(Adt::Enum(_)), Namespace::Values) => Ty::Unknown,
-        (TypableDef::EnumVariant(_), Namespace::Types) => Ty::Unknown,
-        (TypableDef::TypeAlias(_), Namespace::Values) => Ty::Unknown,
-        (TypableDef::Const(_), Namespace::Types) => Ty::Unknown,
-        (TypableDef::Static(_), Namespace::Types) => Ty::Unknown,
-        (TypableDef::BuiltinType(_), Namespace::Values) => Ty::Unknown,
-    }
-}
-
 /// Build the signature of a callable item (function, struct or enum variant).
-pub(crate) fn callable_item_sig(db: &impl HirDatabase, def: CallableDef) -> FnSig {
+pub fn callable_item_sig(db: &impl HirDatabase, def: CallableDef) -> FnSig {
     match def {
-        CallableDef::Function(f) => fn_sig_for_fn(db, f),
-        CallableDef::Struct(s) => fn_sig_for_struct_constructor(db, s),
-        CallableDef::EnumVariant(e) => fn_sig_for_enum_variant_constructor(db, e),
+        CallableDef::FunctionId(f) => fn_sig_for_fn(db, f),
+        CallableDef::StructId(s) => fn_sig_for_struct_constructor(db, s),
+        CallableDef::EnumVariantId(e) => fn_sig_for_enum_variant_constructor(db, e),
     }
 }
 
@@ -555,12 +497,11 @@ pub(crate) fn field_types_query(
     db: &impl HirDatabase,
     variant_id: VariantId,
 ) -> Arc<ArenaMap<LocalStructFieldId, Ty>> {
-    let (resolver, var_data) = match variant_id {
-        VariantId::StructId(it) => (it.resolver(db), db.struct_data(it.0).variant_data.clone()),
-        VariantId::EnumVariantId(it) => (
-            it.parent.resolver(db),
-            db.enum_data(it.parent).variants[it.local_id].variant_data.clone(),
-        ),
+    let var_data = variant_data(db, variant_id);
+    let resolver = match variant_id {
+        VariantId::StructId(it) => it.resolver(db),
+        VariantId::UnionId(it) => it.resolver(db),
+        VariantId::EnumVariantId(it) => it.parent.resolver(db),
     };
     let mut res = ArenaMap::default();
     for (field_id, field_data) in var_data.fields().iter() {
@@ -579,10 +520,10 @@ pub(crate) fn field_types_query(
 /// these are fine: `T: Foo<U::Item>, U: Foo<()>`.
 pub(crate) fn generic_predicates_for_param_query(
     db: &impl HirDatabase,
-    def: GenericDef,
+    def: GenericDefId,
     param_idx: u32,
 ) -> Arc<[GenericPredicate]> {
-    let resolver = GenericDefId::from(def).resolver(db);
+    let resolver = def.resolver(db);
     resolver
         .where_predicates_in_scope()
         // we have to filter out all other predicates *first*, before attempting to lower them
@@ -591,24 +532,23 @@ pub(crate) fn generic_predicates_for_param_query(
         .collect()
 }
 
-pub(crate) fn trait_env(
-    db: &impl HirDatabase,
-    resolver: &Resolver,
-) -> Arc<super::TraitEnvironment> {
-    let predicates = resolver
-        .where_predicates_in_scope()
-        .flat_map(|pred| GenericPredicate::from_where_predicate(db, &resolver, pred))
-        .collect::<Vec<_>>();
+impl TraitEnvironment {
+    pub fn lower(db: &impl HirDatabase, resolver: &Resolver) -> Arc<TraitEnvironment> {
+        let predicates = resolver
+            .where_predicates_in_scope()
+            .flat_map(|pred| GenericPredicate::from_where_predicate(db, &resolver, pred))
+            .collect::<Vec<_>>();
 
-    Arc::new(super::TraitEnvironment { predicates })
+        Arc::new(TraitEnvironment { predicates })
+    }
 }
 
 /// Resolve the where clause(s) of an item with generics.
 pub(crate) fn generic_predicates_query(
     db: &impl HirDatabase,
-    def: GenericDef,
+    def: GenericDefId,
 ) -> Arc<[GenericPredicate]> {
-    let resolver = GenericDefId::from(def).resolver(db);
+    let resolver = def.resolver(db);
     resolver
         .where_predicates_in_scope()
         .flat_map(|pred| GenericPredicate::from_where_predicate(db, &resolver, pred))
@@ -616,8 +556,8 @@ pub(crate) fn generic_predicates_query(
 }
 
 /// Resolve the default type params from generics
-pub(crate) fn generic_defaults_query(db: &impl HirDatabase, def: GenericDef) -> Substs {
-    let resolver = GenericDefId::from(def).resolver(db);
+pub(crate) fn generic_defaults_query(db: &impl HirDatabase, def: GenericDefId) -> Substs {
+    let resolver = def.resolver(db);
     let generic_params = db.generic_params(def.into());
 
     let defaults = generic_params
@@ -629,9 +569,9 @@ pub(crate) fn generic_defaults_query(db: &impl HirDatabase, def: GenericDef) ->
     Substs(defaults)
 }
 
-fn fn_sig_for_fn(db: &impl HirDatabase, def: Function) -> FnSig {
-    let data = db.function_data(def.id);
-    let resolver = def.id.resolver(db);
+fn fn_sig_for_fn(db: &impl HirDatabase, def: FunctionId) -> FnSig {
+    let data = db.function_data(def);
+    let resolver = def.resolver(db);
     let params = data.params.iter().map(|tr| Ty::from_hir(db, &resolver, tr)).collect::<Vec<_>>();
     let ret = Ty::from_hir(db, &resolver, &data.ret_type);
     FnSig::from_params_and_return(params, ret)
@@ -639,24 +579,24 @@ fn fn_sig_for_fn(db: &impl HirDatabase, def: Function) -> FnSig {
 
 /// Build the declared type of a function. This should not need to look at the
 /// function body.
-fn type_for_fn(db: &impl HirDatabase, def: Function) -> Ty {
-    let generics = db.generic_params(def.id.into());
+fn type_for_fn(db: &impl HirDatabase, def: FunctionId) -> Ty {
+    let generics = db.generic_params(def.into());
     let substs = Substs::identity(&generics);
     Ty::apply(TypeCtor::FnDef(def.into()), substs)
 }
 
 /// Build the declared type of a const.
-fn type_for_const(db: &impl HirDatabase, def: Const) -> Ty {
-    let data = db.const_data(def.id);
-    let resolver = def.id.resolver(db);
+fn type_for_const(db: &impl HirDatabase, def: ConstId) -> Ty {
+    let data = db.const_data(def);
+    let resolver = def.resolver(db);
 
     Ty::from_hir(db, &resolver, &data.type_ref)
 }
 
 /// Build the declared type of a static.
-fn type_for_static(db: &impl HirDatabase, def: Static) -> Ty {
-    let data = db.static_data(def.id);
-    let resolver = def.id.resolver(db);
+fn type_for_static(db: &impl HirDatabase, def: StaticId) -> Ty {
+    let data = db.static_data(def);
+    let resolver = def.resolver(db);
 
     Ty::from_hir(db, &resolver, &data.type_ref)
 }
@@ -672,160 +612,148 @@ fn type_for_builtin(def: BuiltinType) -> Ty {
     })
 }
 
-impl From<BuiltinInt> for IntTy {
-    fn from(t: BuiltinInt) -> Self {
-        IntTy { signedness: t.signedness, bitness: t.bitness }
-    }
-}
-
-impl From<BuiltinFloat> for FloatTy {
-    fn from(t: BuiltinFloat) -> Self {
-        FloatTy { bitness: t.bitness }
-    }
-}
-
-impl From<Option<BuiltinInt>> for Uncertain<IntTy> {
-    fn from(t: Option<BuiltinInt>) -> Self {
-        match t {
-            None => Uncertain::Unknown,
-            Some(t) => Uncertain::Known(t.into()),
-        }
-    }
-}
-
-impl From<Option<BuiltinFloat>> for Uncertain<FloatTy> {
-    fn from(t: Option<BuiltinFloat>) -> Self {
-        match t {
-            None => Uncertain::Unknown,
-            Some(t) => Uncertain::Known(t.into()),
-        }
-    }
-}
-
-fn fn_sig_for_struct_constructor(db: &impl HirDatabase, def: Struct) -> FnSig {
-    let struct_data = db.struct_data(def.id.into());
+fn fn_sig_for_struct_constructor(db: &impl HirDatabase, def: StructId) -> FnSig {
+    let struct_data = db.struct_data(def.into());
     let fields = struct_data.variant_data.fields();
-    let resolver = def.id.resolver(db);
+    let resolver = def.resolver(db);
     let params = fields
         .iter()
         .map(|(_, field)| Ty::from_hir(db, &resolver, &field.type_ref))
         .collect::<Vec<_>>();
-    let ret = type_for_adt(db, def);
+    let ret = type_for_adt(db, def.into());
     FnSig::from_params_and_return(params, ret)
 }
 
 /// Build the type of a tuple struct constructor.
-fn type_for_struct_constructor(db: &impl HirDatabase, def: Struct) -> Ty {
-    let struct_data = db.struct_data(def.id.into());
+fn type_for_struct_constructor(db: &impl HirDatabase, def: StructId) -> Ty {
+    let struct_data = db.struct_data(def.into());
     if struct_data.variant_data.is_unit() {
-        return type_for_adt(db, def); // Unit struct
+        return type_for_adt(db, def.into()); // Unit struct
     }
-    let generics = db.generic_params(def.id.into());
+    let generics = db.generic_params(def.into());
     let substs = Substs::identity(&generics);
     Ty::apply(TypeCtor::FnDef(def.into()), substs)
 }
 
-fn fn_sig_for_enum_variant_constructor(db: &impl HirDatabase, def: EnumVariant) -> FnSig {
-    let var_data = def.variant_data(db);
-    let fields = var_data.fields();
-    let resolver = def.parent.id.resolver(db);
+fn fn_sig_for_enum_variant_constructor(db: &impl HirDatabase, def: EnumVariantId) -> FnSig {
+    let enum_data = db.enum_data(def.parent);
+    let var_data = &enum_data.variants[def.local_id];
+    let fields = var_data.variant_data.fields();
+    let resolver = def.parent.resolver(db);
     let params = fields
         .iter()
         .map(|(_, field)| Ty::from_hir(db, &resolver, &field.type_ref))
         .collect::<Vec<_>>();
-    let generics = db.generic_params(def.parent_enum(db).id.into());
+    let generics = db.generic_params(def.parent.into());
     let substs = Substs::identity(&generics);
-    let ret = type_for_adt(db, def.parent_enum(db)).subst(&substs);
+    let ret = type_for_adt(db, def.parent.into()).subst(&substs);
     FnSig::from_params_and_return(params, ret)
 }
 
 /// Build the type of a tuple enum variant constructor.
-fn type_for_enum_variant_constructor(db: &impl HirDatabase, def: EnumVariant) -> Ty {
-    let var_data = def.variant_data(db);
+fn type_for_enum_variant_constructor(db: &impl HirDatabase, def: EnumVariantId) -> Ty {
+    let enum_data = db.enum_data(def.parent);
+    let var_data = &enum_data.variants[def.local_id].variant_data;
     if var_data.is_unit() {
-        return type_for_adt(db, def.parent_enum(db)); // Unit variant
+        return type_for_adt(db, def.parent.into()); // Unit variant
     }
-    let generics = db.generic_params(def.parent_enum(db).id.into());
+    let generics = db.generic_params(def.parent.into());
     let substs = Substs::identity(&generics);
-    Ty::apply(TypeCtor::FnDef(def.into()), substs)
+    Ty::apply(TypeCtor::FnDef(EnumVariantId::from(def).into()), substs)
 }
 
-fn type_for_adt(db: &impl HirDatabase, adt: impl Into<Adt>) -> Ty {
-    let adt = adt.into();
-    let adt_id: AdtId = adt.into();
-    let generics = db.generic_params(adt_id.into());
+fn type_for_adt(db: &impl HirDatabase, adt: AdtId) -> Ty {
+    let generics = db.generic_params(adt.into());
     Ty::apply(TypeCtor::Adt(adt), Substs::identity(&generics))
 }
 
-fn type_for_type_alias(db: &impl HirDatabase, t: TypeAlias) -> Ty {
-    let generics = db.generic_params(t.id.into());
-    let resolver = t.id.resolver(db);
-    let type_ref = t.type_ref(db);
+fn type_for_type_alias(db: &impl HirDatabase, t: TypeAliasId) -> Ty {
+    let generics = db.generic_params(t.into());
+    let resolver = t.resolver(db);
+    let type_ref = &db.type_alias_data(t).type_ref;
     let substs = Substs::identity(&generics);
-    let inner = Ty::from_hir(db, &resolver, &type_ref.unwrap_or(TypeRef::Error));
+    let inner = Ty::from_hir(db, &resolver, type_ref.as_ref().unwrap_or(&TypeRef::Error));
     inner.subst(&substs)
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum TypableDef {
-    Function(Function),
-    Adt(Adt),
-    EnumVariant(EnumVariant),
-    TypeAlias(TypeAlias),
-    Const(Const),
-    Static(Static),
-    BuiltinType(BuiltinType),
-}
-impl_froms!(
-    TypableDef: Function,
-    Adt(Struct, Enum, Union),
-    EnumVariant,
-    TypeAlias,
-    Const,
-    Static,
-    BuiltinType
-);
-
-impl From<ModuleDef> for Option<TypableDef> {
-    fn from(def: ModuleDef) -> Option<TypableDef> {
-        let res = match def {
-            ModuleDef::Function(f) => f.into(),
-            ModuleDef::Adt(adt) => adt.into(),
-            ModuleDef::EnumVariant(v) => v.into(),
-            ModuleDef::TypeAlias(t) => t.into(),
-            ModuleDef::Const(v) => v.into(),
-            ModuleDef::Static(v) => v.into(),
-            ModuleDef::BuiltinType(t) => t.into(),
-            ModuleDef::Module(_) | ModuleDef::Trait(_) => return None,
-        };
-        Some(res)
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub enum CallableDef {
-    Function(Function),
-    Struct(Struct),
-    EnumVariant(EnumVariant),
+    FunctionId(FunctionId),
+    StructId(StructId),
+    EnumVariantId(EnumVariantId),
 }
-impl_froms!(CallableDef: Function, Struct, EnumVariant);
+impl_froms!(CallableDef: FunctionId, StructId, EnumVariantId);
 
 impl CallableDef {
-    pub fn krate(self, db: &impl HirDatabase) -> Option<crate::Crate> {
+    pub fn krate(self, db: &impl HirDatabase) -> CrateId {
         match self {
-            CallableDef::Function(f) => f.krate(db),
-            CallableDef::Struct(s) => s.krate(db),
-            CallableDef::EnumVariant(e) => e.parent_enum(db).krate(db),
+            CallableDef::FunctionId(f) => f.lookup(db).module(db).krate,
+            CallableDef::StructId(s) => s.module(db).krate,
+            CallableDef::EnumVariantId(e) => e.parent.module(db).krate,
         }
     }
 }
 
-impl From<CallableDef> for GenericDef {
-    fn from(def: CallableDef) -> GenericDef {
+impl From<CallableDef> for GenericDefId {
+    fn from(def: CallableDef) -> GenericDefId {
         match def {
-            CallableDef::Function(f) => f.into(),
-            CallableDef::Struct(s) => s.into(),
-            CallableDef::EnumVariant(e) => e.into(),
+            CallableDef::FunctionId(f) => f.into(),
+            CallableDef::StructId(s) => s.into(),
+            CallableDef::EnumVariantId(e) => e.into(),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum TyDefId {
+    BuiltinType(BuiltinType),
+    AdtId(AdtId),
+    TypeAliasId(TypeAliasId),
+}
+impl_froms!(TyDefId: BuiltinType, AdtId(StructId, EnumId, UnionId), TypeAliasId);
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum ValueTyDefId {
+    FunctionId(FunctionId),
+    StructId(StructId),
+    EnumVariantId(EnumVariantId),
+    ConstId(ConstId),
+    StaticId(StaticId),
+}
+impl_froms!(ValueTyDefId: FunctionId, StructId, EnumVariantId, ConstId, StaticId);
+
+/// Build the declared type of an item. This depends on the namespace; e.g. for
+/// `struct Foo(usize)`, we have two types: The type of the struct itself, and
+/// the constructor function `(usize) -> Foo` which lives in the values
+/// namespace.
+pub(crate) fn ty_query(db: &impl HirDatabase, def: TyDefId) -> Ty {
+    match def {
+        TyDefId::BuiltinType(it) => type_for_builtin(it),
+        TyDefId::AdtId(it) => type_for_adt(db, it),
+        TyDefId::TypeAliasId(it) => type_for_type_alias(db, it),
+    }
+}
+pub(crate) fn value_ty_query(db: &impl HirDatabase, def: ValueTyDefId) -> Ty {
+    match def {
+        ValueTyDefId::FunctionId(it) => type_for_fn(db, it),
+        ValueTyDefId::StructId(it) => type_for_struct_constructor(db, it),
+        ValueTyDefId::EnumVariantId(it) => type_for_enum_variant_constructor(db, it),
+        ValueTyDefId::ConstId(it) => type_for_const(db, it),
+        ValueTyDefId::StaticId(it) => type_for_static(db, it),
+    }
+}
+
+pub(crate) fn impl_ty_query(db: &impl HirDatabase, impl_id: ImplId) -> ImplTy {
+    let impl_data = db.impl_data(impl_id);
+    let resolver = impl_id.resolver(db);
+    let self_ty = Ty::from_hir(db, &resolver, &impl_data.target_type);
+    match impl_data.target_trait.as_ref() {
+        Some(trait_ref) => {
+            match TraitRef::from_hir(db, &resolver, trait_ref, Some(self_ty.clone())) {
+                Some(it) => ImplTy::TraitRef(it),
+                None => ImplTy::Inherent(self_ty),
+            }
         }
+        None => ImplTy::Inherent(self_ty),
     }
 }
diff --git a/crates/ra_hir/src/marks.rs b/crates/ra_hir_ty/src/marks.rs
index 0f754eb9c..0f754eb9c 100644
--- a/crates/ra_hir/src/marks.rs
+++ b/crates/ra_hir_ty/src/marks.rs
diff --git a/crates/ra_hir/src/ty/method_resolution.rs b/crates/ra_hir_ty/src/method_resolution.rs
index caa5f5f74..ee1936b0e 100644
--- a/crates/ra_hir/src/ty/method_resolution.rs
+++ b/crates/ra_hir_ty/src/method_resolution.rs
@@ -5,18 +5,23 @@
 use std::sync::Arc;
 
 use arrayvec::ArrayVec;
-use hir_def::{lang_item::LangItemTarget, resolver::Resolver, AstItemDef};
+use hir_def::{
+    lang_item::LangItemTarget, resolver::Resolver, type_ref::Mutability, AssocItemId, AstItemDef,
+    FunctionId, HasModule, ImplId, TraitId,
+};
+use hir_expand::name::Name;
+use ra_db::CrateId;
+use ra_prof::profile;
 use rustc_hash::FxHashMap;
 
 use crate::{
+    autoderef,
     db::HirDatabase,
-    ty::primitive::{FloatBitness, Uncertain},
-    ty::{Ty, TypeCtor},
-    AssocItem, Crate, Function, ImplBlock, Module, Mutability, Name, Trait,
+    primitive::{FloatBitness, Uncertain},
+    utils::all_super_traits,
+    Canonical, ImplTy, InEnvironment, TraitEnvironment, TraitRef, Ty, TypeCtor,
 };
 
-use super::{autoderef, lower, Canonical, InEnvironment, TraitEnvironment, TraitRef};
-
 /// This is used as a key for indexing impls.
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub enum TyFingerprint {
@@ -37,99 +42,101 @@ impl TyFingerprint {
 
 #[derive(Debug, PartialEq, Eq)]
 pub struct CrateImplBlocks {
-    impls: FxHashMap<TyFingerprint, Vec<ImplBlock>>,
-    impls_by_trait: FxHashMap<Trait, Vec<ImplBlock>>,
+    impls: FxHashMap<TyFingerprint, Vec<ImplId>>,
+    impls_by_trait: FxHashMap<TraitId, Vec<ImplId>>,
 }
 
 impl CrateImplBlocks {
     pub(crate) fn impls_in_crate_query(
         db: &impl HirDatabase,
-        krate: Crate,
+        krate: CrateId,
     ) -> Arc<CrateImplBlocks> {
-        let mut crate_impl_blocks =
+        let _p = profile("impls_in_crate_query");
+        let mut res =
             CrateImplBlocks { impls: FxHashMap::default(), impls_by_trait: FxHashMap::default() };
-        if let Some(module) = krate.root_module(db) {
-            crate_impl_blocks.collect_recursive(db, module);
+
+        let crate_def_map = db.crate_def_map(krate);
+        for (_module_id, module_data) in crate_def_map.modules.iter() {
+            for &impl_id in module_data.impls.iter() {
+                match db.impl_ty(impl_id) {
+                    ImplTy::TraitRef(tr) => {
+                        res.impls_by_trait.entry(tr.trait_).or_default().push(impl_id);
+                    }
+                    ImplTy::Inherent(self_ty) => {
+                        if let Some(self_ty_fp) = TyFingerprint::for_impl(&self_ty) {
+                            res.impls.entry(self_ty_fp).or_default().push(impl_id);
+                        }
+                    }
+                }
+            }
         }
-        Arc::new(crate_impl_blocks)
+
+        Arc::new(res)
     }
-    pub fn lookup_impl_blocks(&self, ty: &Ty) -> impl Iterator<Item = ImplBlock> + '_ {
+    pub fn lookup_impl_blocks(&self, ty: &Ty) -> impl Iterator<Item = ImplId> + '_ {
         let fingerprint = TyFingerprint::for_impl(ty);
         fingerprint.and_then(|f| self.impls.get(&f)).into_iter().flatten().copied()
     }
 
-    pub fn lookup_impl_blocks_for_trait(&self, tr: Trait) -> impl Iterator<Item = ImplBlock> + '_ {
+    pub fn lookup_impl_blocks_for_trait(&self, tr: TraitId) -> impl Iterator<Item = ImplId> + '_ {
         self.impls_by_trait.get(&tr).into_iter().flatten().copied()
     }
 
-    pub fn all_impls<'a>(&'a self) -> impl Iterator<Item = ImplBlock> + 'a {
+    pub fn all_impls<'a>(&'a self) -> impl Iterator<Item = ImplId> + 'a {
         self.impls.values().chain(self.impls_by_trait.values()).flatten().copied()
     }
-
-    fn collect_recursive(&mut self, db: &impl HirDatabase, module: Module) {
-        for impl_block in module.impl_blocks(db) {
-            let target_ty = impl_block.target_ty(db);
-
-            if impl_block.target_trait(db).is_some() {
-                if let Some(tr) = impl_block.target_trait_ref(db) {
-                    self.impls_by_trait.entry(tr.trait_).or_default().push(impl_block);
-                }
-            } else {
-                if let Some(target_ty_fp) = TyFingerprint::for_impl(&target_ty) {
-                    self.impls.entry(target_ty_fp).or_default().push(impl_block);
-                }
-            }
-        }
-
-        for child in module.children(db) {
-            self.collect_recursive(db, child);
-        }
-    }
 }
 
-fn def_crates(db: &impl HirDatabase, cur_crate: Crate, ty: &Ty) -> Option<ArrayVec<[Crate; 2]>> {
-    // Types like slice can have inherent impls in several crates, (core and alloc).
-    // The corresponding impls are marked with lang items, so we can use them to find the required crates.
-    macro_rules! lang_item_crate {
+impl Ty {
+    pub fn def_crates(
+        &self,
+        db: &impl HirDatabase,
+        cur_crate: CrateId,
+    ) -> Option<ArrayVec<[CrateId; 2]>> {
+        // Types like slice can have inherent impls in several crates, (core and alloc).
+        // The corresponding impls are marked with lang items, so we can use them to find the required crates.
+        macro_rules! lang_item_crate {
         ($($name:expr),+ $(,)?) => {{
             let mut v = ArrayVec::<[LangItemTarget; 2]>::new();
             $(
-                v.extend(db.lang_item(cur_crate.crate_id, $name.into()));
+                v.extend(db.lang_item(cur_crate, $name.into()));
             )+
             v
         }};
     }
 
-    let lang_item_targets = match ty {
-        Ty::Apply(a_ty) => match a_ty.ctor {
-            TypeCtor::Adt(def_id) => return Some(std::iter::once(def_id.krate(db)?).collect()),
-            TypeCtor::Bool => lang_item_crate!("bool"),
-            TypeCtor::Char => lang_item_crate!("char"),
-            TypeCtor::Float(Uncertain::Known(f)) => match f.bitness {
-                // There are two lang items: one in libcore (fXX) and one in libstd (fXX_runtime)
-                FloatBitness::X32 => lang_item_crate!("f32", "f32_runtime"),
-                FloatBitness::X64 => lang_item_crate!("f64", "f64_runtime"),
+        let lang_item_targets = match self {
+            Ty::Apply(a_ty) => match a_ty.ctor {
+                TypeCtor::Adt(def_id) => {
+                    return Some(std::iter::once(def_id.module(db).krate).collect())
+                }
+                TypeCtor::Bool => lang_item_crate!("bool"),
+                TypeCtor::Char => lang_item_crate!("char"),
+                TypeCtor::Float(Uncertain::Known(f)) => match f.bitness {
+                    // There are two lang items: one in libcore (fXX) and one in libstd (fXX_runtime)
+                    FloatBitness::X32 => lang_item_crate!("f32", "f32_runtime"),
+                    FloatBitness::X64 => lang_item_crate!("f64", "f64_runtime"),
+                },
+                TypeCtor::Int(Uncertain::Known(i)) => lang_item_crate!(i.ty_to_string()),
+                TypeCtor::Str => lang_item_crate!("str_alloc", "str"),
+                TypeCtor::Slice => lang_item_crate!("slice_alloc", "slice"),
+                TypeCtor::RawPtr(Mutability::Shared) => lang_item_crate!("const_ptr"),
+                TypeCtor::RawPtr(Mutability::Mut) => lang_item_crate!("mut_ptr"),
+                _ => return None,
             },
-            TypeCtor::Int(Uncertain::Known(i)) => lang_item_crate!(i.ty_to_string()),
-            TypeCtor::Str => lang_item_crate!("str_alloc", "str"),
-            TypeCtor::Slice => lang_item_crate!("slice_alloc", "slice"),
-            TypeCtor::RawPtr(Mutability::Shared) => lang_item_crate!("const_ptr"),
-            TypeCtor::RawPtr(Mutability::Mut) => lang_item_crate!("mut_ptr"),
             _ => return None,
-        },
-        _ => return None,
-    };
-    let res = lang_item_targets
-        .into_iter()
-        .filter_map(|it| match it {
-            LangItemTarget::ImplBlockId(it) => Some(it),
-            _ => None,
-        })
-        .map(|it| it.module(db).krate.into())
-        .collect();
-    Some(res)
+        };
+        let res = lang_item_targets
+            .into_iter()
+            .filter_map(|it| match it {
+                LangItemTarget::ImplBlockId(it) => Some(it),
+                _ => None,
+            })
+            .map(|it| it.module(db).krate)
+            .collect();
+        Some(res)
+    }
 }
-
 /// Look up the method with the given name, returning the actual autoderefed
 /// receiver type (but without autoref applied yet).
 pub(crate) fn lookup_method(
@@ -137,10 +144,10 @@ pub(crate) fn lookup_method(
     db: &impl HirDatabase,
     name: &Name,
     resolver: &Resolver,
-) -> Option<(Ty, Function)> {
+) -> Option<(Ty, FunctionId)> {
     iterate_method_candidates(ty, db, resolver, Some(name), LookupMode::MethodCall, |ty, f| match f
     {
-        AssocItem::Function(f) => Some((ty.clone(), f)),
+        AssocItemId::FunctionId(f) => Some((ty.clone(), f)),
         _ => None,
     })
 }
@@ -160,13 +167,13 @@ pub enum LookupMode {
 // This would be nicer if it just returned an iterator, but that runs into
 // lifetime problems, because we need to borrow temp `CrateImplBlocks`.
 // FIXME add a context type here?
-pub(crate) fn iterate_method_candidates<T>(
+pub fn iterate_method_candidates<T>(
     ty: &Canonical<Ty>,
     db: &impl HirDatabase,
     resolver: &Resolver,
     name: Option<&Name>,
     mode: LookupMode,
-    mut callback: impl FnMut(&Ty, AssocItem) -> Option<T>,
+    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
     let krate = resolver.krate()?;
     match mode {
@@ -179,16 +186,12 @@ pub(crate) fn iterate_method_candidates<T>(
             // Also note that when we've got a receiver like &S, even if the method we
             // find in the end takes &self, we still do the autoderef step (just as
             // rustc does an autoderef and then autoref again).
-
-            for derefed_ty in autoderef::autoderef(db, resolver, ty.clone()) {
-                if let Some(result) = iterate_inherent_methods(
-                    &derefed_ty,
-                    db,
-                    name,
-                    mode,
-                    krate.into(),
-                    &mut callback,
-                ) {
+            let environment = TraitEnvironment::lower(db, resolver);
+            let ty = InEnvironment { value: ty.clone(), environment };
+            for derefed_ty in autoderef::autoderef(db, resolver.krate(), ty) {
+                if let Some(result) =
+                    iterate_inherent_methods(&derefed_ty, db, name, mode, krate, &mut callback)
+                {
                     return Some(result);
                 }
                 if let Some(result) = iterate_trait_method_candidates(
@@ -226,30 +229,29 @@ fn iterate_trait_method_candidates<T>(
     resolver: &Resolver,
     name: Option<&Name>,
     mode: LookupMode,
-    mut callback: impl FnMut(&Ty, AssocItem) -> Option<T>,
+    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
     let krate = resolver.krate()?;
     // FIXME: maybe put the trait_env behind a query (need to figure out good input parameters for that)
-    let env = lower::trait_env(db, resolver);
+    let env = TraitEnvironment::lower(db, resolver);
     // if ty is `impl Trait` or `dyn Trait`, the trait doesn't need to be in scope
     let inherent_trait = ty.value.inherent_trait().into_iter();
     // if we have `T: Trait` in the param env, the trait doesn't need to be in scope
     let traits_from_env = env
         .trait_predicates_for_self_ty(&ty.value)
         .map(|tr| tr.trait_)
-        .flat_map(|t| t.all_super_traits(db));
-    let traits = inherent_trait
-        .chain(traits_from_env)
-        .chain(resolver.traits_in_scope(db).into_iter().map(Trait::from));
+        .flat_map(|t| all_super_traits(db, t));
+    let traits =
+        inherent_trait.chain(traits_from_env).chain(resolver.traits_in_scope(db).into_iter());
     'traits: for t in traits {
-        let data = db.trait_data(t.id);
+        let data = db.trait_data(t);
 
         // we'll be lazy about checking whether the type implements the
         // trait, but if we find out it doesn't, we'll skip the rest of the
         // iteration
         let mut known_implemented = false;
-        for &item in data.items.iter() {
-            if !is_valid_candidate(db, name, mode, item.into()) {
+        for (_name, item) in data.items.iter() {
+            if !is_valid_candidate(db, name, mode, (*item).into()) {
                 continue;
             }
             if !known_implemented {
@@ -259,7 +261,7 @@ fn iterate_trait_method_candidates<T>(
                 }
             }
             known_implemented = true;
-            if let Some(result) = callback(&ty.value, item.into()) {
+            if let Some(result) = callback(&ty.value, (*item).into()) {
                 return Some(result);
             }
         }
@@ -272,18 +274,18 @@ fn iterate_inherent_methods<T>(
     db: &impl HirDatabase,
     name: Option<&Name>,
     mode: LookupMode,
-    krate: Crate,
-    mut callback: impl FnMut(&Ty, AssocItem) -> Option<T>,
+    krate: CrateId,
+    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
-    for krate in def_crates(db, krate, &ty.value)? {
+    for krate in ty.value.def_crates(db, krate)? {
         let impls = db.impls_in_crate(krate);
 
         for impl_block in impls.lookup_impl_blocks(&ty.value) {
-            for item in impl_block.items(db) {
+            for &item in db.impl_data(impl_block).items.iter() {
                 if !is_valid_candidate(db, name, mode, item) {
                     continue;
                 }
-                if let Some(result) = callback(&ty.value, item) {
+                if let Some(result) = callback(&ty.value, item.into()) {
                     return Some(result);
                 }
             }
@@ -296,71 +298,47 @@ fn is_valid_candidate(
     db: &impl HirDatabase,
     name: Option<&Name>,
     mode: LookupMode,
-    item: AssocItem,
+    item: AssocItemId,
 ) -> bool {
     match item {
-        AssocItem::Function(m) => {
-            let data = db.function_data(m.id);
-            name.map_or(true, |name| data.name == *name)
+        AssocItemId::FunctionId(m) => {
+            let data = db.function_data(m);
+            name.map_or(true, |name| &data.name == name)
                 && (data.has_self_param || mode == LookupMode::Path)
         }
-        AssocItem::Const(c) => {
-            name.map_or(true, |name| Some(name) == c.name(db).as_ref())
-                && (mode == LookupMode::Path)
+        AssocItemId::ConstId(c) => {
+            let data = db.const_data(c);
+            name.map_or(true, |name| data.name.as_ref() == Some(name)) && (mode == LookupMode::Path)
         }
         _ => false,
     }
 }
 
-pub(crate) fn implements_trait(
+pub fn implements_trait(
     ty: &Canonical<Ty>,
     db: &impl HirDatabase,
     resolver: &Resolver,
-    krate: Crate,
-    trait_: Trait,
+    krate: CrateId,
+    trait_: TraitId,
 ) -> bool {
     if ty.value.inherent_trait() == Some(trait_) {
         // FIXME this is a bit of a hack, since Chalk should say the same thing
         // anyway, but currently Chalk doesn't implement `dyn/impl Trait` yet
         return true;
     }
-    let env = lower::trait_env(db, resolver);
+    let env = TraitEnvironment::lower(db, resolver);
     let goal = generic_implements_goal(db, env, trait_, ty.clone());
-    let solution = db.trait_solve(krate, goal);
+    let solution = db.trait_solve(krate.into(), goal);
 
     solution.is_some()
 }
 
-impl Ty {
-    // This would be nicer if it just returned an iterator, but that runs into
-    // lifetime problems, because we need to borrow temp `CrateImplBlocks`.
-    pub fn iterate_impl_items<T>(
-        self,
-        db: &impl HirDatabase,
-        krate: Crate,
-        mut callback: impl FnMut(AssocItem) -> Option<T>,
-    ) -> Option<T> {
-        for krate in def_crates(db, krate, &self)? {
-            let impls = db.impls_in_crate(krate);
-
-            for impl_block in impls.lookup_impl_blocks(&self) {
-                for item in impl_block.items(db) {
-                    if let Some(result) = callback(item) {
-                        return Some(result);
-                    }
-                }
-            }
-        }
-        None
-    }
-}
-
 /// This creates Substs for a trait with the given Self type and type variables
 /// for all other parameters, to query Chalk with it.
 fn generic_implements_goal(
     db: &impl HirDatabase,
     env: Arc<TraitEnvironment>,
-    trait_: Trait,
+    trait_: TraitId,
     self_ty: Canonical<Ty>,
 ) -> Canonical<InEnvironment<super::Obligation>> {
     let num_vars = self_ty.num_vars;
diff --git a/crates/ra_hir/src/ty/op.rs b/crates/ra_hir_ty/src/op.rs
index bcfa3a6a2..09c47a76d 100644
--- a/crates/ra_hir/src/ty/op.rs
+++ b/crates/ra_hir_ty/src/op.rs
@@ -1,10 +1,8 @@
 //! FIXME: write short doc here
+use hir_def::expr::{BinaryOp, CmpOp};
 
 use super::{InferTy, Ty, TypeCtor};
-use crate::{
-    expr::{BinaryOp, CmpOp},
-    ty::ApplicationTy,
-};
+use crate::ApplicationTy;
 
 pub(super) fn binary_op_return_ty(op: BinaryOp, rhs_ty: Ty) -> Ty {
     match op {
diff --git a/crates/ra_hir/src/ty/primitive.rs b/crates/ra_hir_ty/src/primitive.rs
index 47789db87..02a8179d9 100644
--- a/crates/ra_hir/src/ty/primitive.rs
+++ b/crates/ra_hir_ty/src/primitive.rs
@@ -1,8 +1,11 @@
-//! FIXME: write short doc here
+//! Defines primitive types, which have a couple of peculiarities:
+//!
+//! * during type inference, they can be uncertain (ie, `let x = 92;`)
+//! * they don't belong to any particular crate.
 
 use std::fmt;
 
-pub use hir_def::builtin_type::{FloatBitness, IntBitness, Signedness};
+pub use hir_def::builtin_type::{BuiltinFloat, BuiltinInt, FloatBitness, IntBitness, Signedness};
 
 #[derive(Clone, Copy, Eq, PartialEq, Hash, Debug)]
 pub enum Uncertain<T> {
@@ -107,7 +110,7 @@ impl IntTy {
         IntTy { signedness: Signedness::Unsigned, bitness: IntBitness::X128 }
     }
 
-    pub(crate) fn ty_to_string(self) -> &'static str {
+    pub fn ty_to_string(self) -> &'static str {
         match (self.signedness, self.bitness) {
             (Signedness::Signed, IntBitness::Xsize) => "isize",
             (Signedness::Signed, IntBitness::X8) => "i8",
@@ -151,10 +154,40 @@ impl FloatTy {
         FloatTy { bitness: FloatBitness::X64 }
     }
 
-    pub(crate) fn ty_to_string(self) -> &'static str {
+    pub fn ty_to_string(self) -> &'static str {
         match self.bitness {
             FloatBitness::X32 => "f32",
             FloatBitness::X64 => "f64",
         }
     }
 }
+
+impl From<BuiltinInt> for IntTy {
+    fn from(t: BuiltinInt) -> Self {
+        IntTy { signedness: t.signedness, bitness: t.bitness }
+    }
+}
+
+impl From<BuiltinFloat> for FloatTy {
+    fn from(t: BuiltinFloat) -> Self {
+        FloatTy { bitness: t.bitness }
+    }
+}
+
+impl From<Option<BuiltinInt>> for Uncertain<IntTy> {
+    fn from(t: Option<BuiltinInt>) -> Self {
+        match t {
+            None => Uncertain::Unknown,
+            Some(t) => Uncertain::Known(t.into()),
+        }
+    }
+}
+
+impl From<Option<BuiltinFloat>> for Uncertain<FloatTy> {
+    fn from(t: Option<BuiltinFloat>) -> Self {
+        match t {
+            None => Uncertain::Unknown,
+            Some(t) => Uncertain::Known(t.into()),
+        }
+    }
+}
diff --git a/crates/ra_hir/src/test_db.rs b/crates/ra_hir_ty/src/test_db.rs
index efee2f658..1dc9793f9 100644
--- a/crates/ra_hir/src/test_db.rs
+++ b/crates/ra_hir_ty/src/test_db.rs
@@ -1,21 +1,23 @@
 //! Database used for testing `hir`.
 
-use std::{panic, sync::Arc};
+use std::{
+    panic,
+    sync::{Arc, Mutex},
+};
 
-use hir_def::{db::DefDatabase, ModuleId};
+use hir_def::{db::DefDatabase, AssocItemId, ModuleDefId, ModuleId};
 use hir_expand::diagnostics::DiagnosticSink;
-use parking_lot::Mutex;
 use ra_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate, RelativePath, SourceDatabase};
 
-use crate::{db, debug::HirDebugHelper};
+use crate::{db::HirDatabase, expr::ExprValidator};
 
 #[salsa::database(
     ra_db::SourceDatabaseExtStorage,
     ra_db::SourceDatabaseStorage,
-    db::InternDatabaseStorage,
-    db::AstDatabaseStorage,
-    db::DefDatabaseStorage,
-    db::HirDatabaseStorage
+    hir_expand::db::AstDatabaseStorage,
+    hir_def::db::InternDatabaseStorage,
+    hir_def::db::DefDatabaseStorage,
+    crate::db::HirDatabaseStorage
 )]
 #[derive(Debug, Default)]
 pub struct TestDB {
@@ -28,8 +30,12 @@ impl salsa::Database for TestDB {
         &self.runtime
     }
 
+    fn salsa_runtime_mut(&mut self) -> &mut salsa::Runtime<Self> {
+        &mut self.runtime
+    }
+
     fn salsa_event(&self, event: impl Fn() -> salsa::Event<TestDB>) {
-        let mut events = self.events.lock();
+        let mut events = self.events.lock().unwrap();
         if let Some(events) = &mut *events {
             events.push(event());
         }
@@ -63,32 +69,53 @@ impl FileLoader for TestDB {
     }
 }
 
-// FIXME: improve `WithFixture` to bring useful hir debugging back
-impl HirDebugHelper for TestDB {
-    fn crate_name(&self, _krate: CrateId) -> Option<String> {
-        None
+impl TestDB {
+    pub fn module_for_file(&self, file_id: FileId) -> ModuleId {
+        for &krate in self.relevant_crates(file_id).iter() {
+            let crate_def_map = self.crate_def_map(krate);
+            for (local_id, data) in crate_def_map.modules.iter() {
+                if data.definition == Some(file_id) {
+                    return ModuleId { krate, local_id };
+                }
+            }
+        }
+        panic!("Can't find module for file")
     }
 
-    fn file_path(&self, _file_id: FileId) -> Option<String> {
-        None
-    }
-}
-
-impl TestDB {
+    // FIXME: don't duplicate this
     pub fn diagnostics(&self) -> String {
         let mut buf = String::new();
         let crate_graph = self.crate_graph();
         for krate in crate_graph.iter().next() {
             let crate_def_map = self.crate_def_map(krate);
+
+            let mut fns = Vec::new();
             for (module_id, _) in crate_def_map.modules.iter() {
-                let module_id = ModuleId { krate, module_id };
-                let module = crate::Module::from(module_id);
-                module.diagnostics(
-                    self,
-                    &mut DiagnosticSink::new(|d| {
-                        buf += &format!("{:?}: {}\n", d.syntax_node(self).text(), d.message());
-                    }),
-                )
+                for decl in crate_def_map[module_id].scope.declarations() {
+                    match decl {
+                        ModuleDefId::FunctionId(f) => fns.push(f),
+                        _ => (),
+                    }
+                }
+
+                for &impl_id in crate_def_map[module_id].impls.iter() {
+                    let impl_data = self.impl_data(impl_id);
+                    for item in impl_data.items.iter() {
+                        if let AssocItemId::FunctionId(f) = item {
+                            fns.push(*f)
+                        }
+                    }
+                }
+            }
+
+            for f in fns {
+                let infer = self.infer(f.into());
+                let mut sink = DiagnosticSink::new(|d| {
+                    buf += &format!("{:?}: {}\n", d.syntax_node(self).text(), d.message());
+                });
+                infer.add_diagnostics(self, f, &mut sink);
+                let mut validator = ExprValidator::new(f, infer, &mut sink);
+                validator.validate_body(self);
             }
         }
         buf
@@ -97,9 +124,9 @@ impl TestDB {
 
 impl TestDB {
     pub fn log(&self, f: impl FnOnce()) -> Vec<salsa::Event<TestDB>> {
-        *self.events.lock() = Some(Vec::new());
+        *self.events.lock().unwrap() = Some(Vec::new());
         f();
-        self.events.lock().take().unwrap()
+        self.events.lock().unwrap().take().unwrap()
     }
 
     pub fn log_executed(&self, f: impl FnOnce()) -> Vec<String> {
diff --git a/crates/ra_hir/src/ty/tests.rs b/crates/ra_hir_ty/src/tests.rs
index 3209c66bd..c8461b447 100644
--- a/crates/ra_hir/src/ty/tests.rs
+++ b/crates/ra_hir_ty/src/tests.rs
@@ -4,20 +4,20 @@ mod coercion;
 use std::fmt::Write;
 use std::sync::Arc;
 
+use hir_def::{
+    body::BodySourceMap, db::DefDatabase, nameres::CrateDefMap, AssocItemId, DefWithBodyId,
+    LocalModuleId, Lookup, ModuleDefId,
+};
+use hir_expand::Source;
 use insta::assert_snapshot;
 use ra_db::{fixture::WithFixture, salsa::Database, FilePosition, SourceDatabase};
 use ra_syntax::{
     algo,
     ast::{self, AstNode},
-    SyntaxKind::*,
 };
-use rustc_hash::FxHashSet;
 use test_utils::covers;
 
-use crate::{
-    expr::BodySourceMap, test_db::TestDB, ty::display::HirDisplay, ty::InferenceResult, Source,
-    SourceAnalyzer,
-};
+use crate::{db::HirDatabase, display::HirDisplay, test_db::TestDB, InferenceResult};
 
 // These tests compare the inference results for all expressions in a file
 // against snapshots of the expected results using insta. Use cargo-insta to
@@ -4674,10 +4674,20 @@ fn test<T, U>() where T: Trait<U::Item>, U: Trait<T::Item> {
 fn type_at_pos(db: &TestDB, pos: FilePosition) -> String {
     let file = db.parse(pos.file_id).ok().unwrap();
     let expr = algo::find_node_at_offset::<ast::Expr>(file.syntax(), pos.offset).unwrap();
-    let analyzer =
-        SourceAnalyzer::new(db, Source::new(pos.file_id.into(), expr.syntax()), Some(pos.offset));
-    let ty = analyzer.type_of(db, &expr).unwrap();
-    ty.display(db).to_string()
+
+    let module = db.module_for_file(pos.file_id);
+    let crate_def_map = db.crate_def_map(module.krate);
+    for decl in crate_def_map[module.local_id].scope.declarations() {
+        if let ModuleDefId::FunctionId(func) = decl {
+            let (_body, source_map) = db.body_with_source_map(func.into());
+            if let Some(expr_id) = source_map.node_expr(Source::new(pos.file_id.into(), &expr)) {
+                let infer = db.infer(func.into());
+                let ty = &infer[expr_id];
+                return ty.display(db).to_string();
+            }
+        }
+    }
+    panic!("Can't find expression")
 }
 
 fn type_at(content: &str) -> String {
@@ -4687,7 +4697,6 @@ fn type_at(content: &str) -> String {
 
 fn infer(content: &str) -> String {
     let (db, file_id) = TestDB::with_single_file(content);
-    let source_file = db.parse(file_id).ok().unwrap();
 
     let mut acc = String::new();
 
@@ -4740,20 +4749,69 @@ fn infer(content: &str) -> String {
         }
     };
 
-    let mut analyzed = FxHashSet::default();
-    for node in source_file.syntax().descendants() {
-        if node.kind() == FN_DEF || node.kind() == CONST_DEF || node.kind() == STATIC_DEF {
-            let analyzer = SourceAnalyzer::new(&db, Source::new(file_id.into(), &node), None);
-            if analyzed.insert(analyzer.analyzed_declaration()) {
-                infer_def(analyzer.inference_result(), analyzer.body_source_map());
-            }
+    let module = db.module_for_file(file_id);
+    let crate_def_map = db.crate_def_map(module.krate);
+
+    let mut defs: Vec<DefWithBodyId> = Vec::new();
+    visit_module(&db, &crate_def_map, module.local_id, &mut |it| defs.push(it));
+    defs.sort_by_key(|def| match def {
+        DefWithBodyId::FunctionId(it) => {
+            it.lookup(&db).ast_id.to_node(&db).syntax().text_range().start()
+        }
+        DefWithBodyId::ConstId(it) => {
+            it.lookup(&db).ast_id.to_node(&db).syntax().text_range().start()
+        }
+        DefWithBodyId::StaticId(it) => {
+            it.lookup(&db).ast_id.to_node(&db).syntax().text_range().start()
         }
+    });
+    for def in defs {
+        let (_body, source_map) = db.body_with_source_map(def);
+        let infer = db.infer(def);
+        infer_def(infer, source_map);
     }
 
     acc.truncate(acc.trim_end().len());
     acc
 }
 
+fn visit_module(
+    db: &TestDB,
+    crate_def_map: &CrateDefMap,
+    module_id: LocalModuleId,
+    cb: &mut dyn FnMut(DefWithBodyId),
+) {
+    for decl in crate_def_map[module_id].scope.declarations() {
+        match decl {
+            ModuleDefId::FunctionId(it) => cb(it.into()),
+            ModuleDefId::ConstId(it) => cb(it.into()),
+            ModuleDefId::StaticId(it) => cb(it.into()),
+            ModuleDefId::TraitId(it) => {
+                let trait_data = db.trait_data(it);
+                for &(_, item) in trait_data.items.iter() {
+                    match item {
+                        AssocItemId::FunctionId(it) => cb(it.into()),
+                        AssocItemId::ConstId(it) => cb(it.into()),
+                        AssocItemId::TypeAliasId(_) => (),
+                    }
+                }
+            }
+            ModuleDefId::ModuleId(it) => visit_module(db, crate_def_map, it.local_id, cb),
+            _ => (),
+        }
+    }
+    for &impl_id in crate_def_map[module_id].impls.iter() {
+        let impl_data = db.impl_data(impl_id);
+        for &item in impl_data.items.iter() {
+            match item {
+                AssocItemId::FunctionId(it) => cb(it.into()),
+                AssocItemId::ConstId(it) => cb(it.into()),
+                AssocItemId::TypeAliasId(_) => (),
+            }
+        }
+    }
+}
+
 fn ellipsize(mut text: String, max_len: usize) -> String {
     if text.len() <= max_len {
         return text;
@@ -4783,10 +4841,12 @@ fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
     ",
     );
     {
-        let file = db.parse(pos.file_id).ok().unwrap();
-        let node = file.syntax().token_at_offset(pos.offset).right_biased().unwrap().parent();
         let events = db.log_executed(|| {
-            SourceAnalyzer::new(&db, Source::new(pos.file_id.into(), &node), None);
+            let module = db.module_for_file(pos.file_id);
+            let crate_def_map = db.crate_def_map(module.krate);
+            visit_module(&db, &crate_def_map, module.local_id, &mut |def| {
+                db.infer(def);
+            });
         });
         assert!(format!("{:?}", events).contains("infer"))
     }
@@ -4803,10 +4863,12 @@ fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
     db.query_mut(ra_db::FileTextQuery).set(pos.file_id, Arc::new(new_text));
 
     {
-        let file = db.parse(pos.file_id).ok().unwrap();
-        let node = file.syntax().token_at_offset(pos.offset).right_biased().unwrap().parent();
         let events = db.log_executed(|| {
-            SourceAnalyzer::new(&db, Source::new(pos.file_id.into(), &node), None);
+            let module = db.module_for_file(pos.file_id);
+            let crate_def_map = db.crate_def_map(module.krate);
+            visit_module(&db, &crate_def_map, module.local_id, &mut |def| {
+                db.infer(def);
+            });
         });
         assert!(!format!("{:?}", events).contains("infer"), "{:#?}", events)
     }
@@ -4832,7 +4894,8 @@ fn no_such_field_diagnostics() {
 
     assert_snapshot!(diagnostics, @r###"
     "baz: 62": no such field
-    "{\n            foo: 92,\n            baz: 62,\n        }": fill structure fields
+    "{\n            foo: 92,\n            baz: 62,\n        }": Missing structure fields:
+    - bar
     "###
     );
 }
diff --git a/crates/ra_hir/src/ty/tests/coercion.rs b/crates/ra_hir_ty/src/tests/coercion.rs
index 1530fcc63..1530fcc63 100644
--- a/crates/ra_hir/src/ty/tests/coercion.rs
+++ b/crates/ra_hir_ty/src/tests/coercion.rs
diff --git a/crates/ra_hir/src/ty/tests/never_type.rs b/crates/ra_hir_ty/src/tests/never_type.rs
index c202f545a..c202f545a 100644
--- a/crates/ra_hir/src/ty/tests/never_type.rs
+++ b/crates/ra_hir_ty/src/tests/never_type.rs
diff --git a/crates/ra_hir/src/ty/traits.rs b/crates/ra_hir_ty/src/traits.rs
index 268fa09e4..76189a60b 100644
--- a/crates/ra_hir/src/ty/traits.rs
+++ b/crates/ra_hir_ty/src/traits.rs
@@ -2,13 +2,15 @@
 use std::sync::{Arc, Mutex};
 
 use chalk_ir::{cast::Cast, family::ChalkIr};
+use hir_def::{expr::ExprId, DefWithBodyId, ImplId, TraitId, TypeAliasId};
 use log::debug;
-use ra_db::{impl_intern_key, salsa};
+use ra_db::{impl_intern_key, salsa, CrateId};
 use ra_prof::profile;
 use rustc_hash::FxHashSet;
 
+use crate::db::HirDatabase;
+
 use super::{Canonical, GenericPredicate, HirDisplay, ProjectionTy, TraitRef, Ty, TypeWalk};
-use crate::{db::HirDatabase, expr::ExprId, Crate, DefWithBody, ImplBlock, Trait, TypeAlias};
 
 use self::chalk::{from_chalk, ToChalk};
 
@@ -16,7 +18,7 @@ pub(crate) mod chalk;
 
 #[derive(Debug, Clone)]
 pub struct TraitSolver {
-    krate: Crate,
+    krate: CrateId,
     inner: Arc<Mutex<chalk_solve::Solver<ChalkIr>>>,
 }
 
@@ -58,12 +60,12 @@ const CHALK_SOLVER_MAX_SIZE: usize = 4;
 #[derive(Debug, Copy, Clone)]
 struct ChalkContext<'a, DB> {
     db: &'a DB,
-    krate: Crate,
+    krate: CrateId,
 }
 
 pub(crate) fn trait_solver_query(
     db: &(impl HirDatabase + salsa::Database),
-    krate: Crate,
+    krate: CrateId,
 ) -> TraitSolver {
     db.salsa_runtime().report_untracked_read();
     // krate parameter is just so we cache a unique solver per crate
@@ -75,17 +77,17 @@ pub(crate) fn trait_solver_query(
 /// Collects impls for the given trait in the whole dependency tree of `krate`.
 pub(crate) fn impls_for_trait_query(
     db: &impl HirDatabase,
-    krate: Crate,
-    trait_: Trait,
-) -> Arc<[ImplBlock]> {
+    krate: CrateId,
+    trait_: TraitId,
+) -> Arc<[ImplId]> {
     let mut impls = FxHashSet::default();
     // We call the query recursively here. On the one hand, this means we can
     // reuse results from queries for different crates; on the other hand, this
     // will only ever get called for a few crates near the root of the tree (the
     // ones the user is editing), so this may actually be a waste of memory. I'm
     // doing it like this mainly for simplicity for now.
-    for dep in krate.dependencies(db) {
-        impls.extend(db.impls_for_trait(dep.krate, trait_).iter());
+    for dep in db.crate_graph().dependencies(krate) {
+        impls.extend(db.impls_for_trait(dep.crate_id, trait_).iter());
     }
     let crate_impl_blocks = db.impls_in_crate(krate);
     impls.extend(crate_impl_blocks.lookup_impl_blocks_for_trait(trait_));
@@ -174,7 +176,7 @@ impl TypeWalk for ProjectionPredicate {
 /// Solve a trait goal using Chalk.
 pub(crate) fn trait_solve_query(
     db: &impl HirDatabase,
-    krate: Crate,
+    krate: CrateId,
     goal: Canonical<InEnvironment<Obligation>>,
 ) -> Option<Solution> {
     let _p = profile("trait_solve_query");
@@ -290,7 +292,7 @@ impl FnTrait {
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct ClosureFnTraitImplData {
-    def: DefWithBody,
+    def: DefWithBodyId,
     expr: ExprId,
     fn_trait: FnTrait,
 }
@@ -300,7 +302,7 @@ pub struct ClosureFnTraitImplData {
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum Impl {
     /// A normal impl from an impl block.
-    ImplBlock(ImplBlock),
+    ImplBlock(ImplId),
     /// Closure types implement the Fn traits synthetically.
     ClosureFnTraitImpl(ClosureFnTraitImplData),
 }
@@ -315,7 +317,7 @@ impl_intern_key!(GlobalImplId);
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum AssocTyValue {
     /// A normal assoc type value from an impl block.
-    TypeAlias(TypeAlias),
+    TypeAlias(TypeAliasId),
     /// The output type of the Fn trait implementation.
     ClosureFnTraitImplOutput(ClosureFnTraitImplData),
 }
diff --git a/crates/ra_hir/src/ty/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index 1a93e5e50..35de37e6b 100644
--- a/crates/ra_hir/src/ty/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -4,22 +4,24 @@ use std::sync::Arc;
 use log::debug;
 
 use chalk_ir::{
-    cast::Cast, family::ChalkIr, Identifier, ImplId, Parameter, PlaceholderIndex, TypeId,
-    TypeKindId, TypeName, UniverseIndex,
+    cast::Cast, family::ChalkIr, Identifier, Parameter, PlaceholderIndex, TypeId, TypeKindId,
+    TypeName, UniverseIndex,
 };
 use chalk_rust_ir::{AssociatedTyDatum, AssociatedTyValue, ImplDatum, StructDatum, TraitDatum};
+use ra_db::CrateId;
 
-use hir_def::lang_item::LangItemTarget;
+use hir_def::{
+    expr::Expr, lang_item::LangItemTarget, AssocItemId, AstItemDef, ContainerId, GenericDefId,
+    ImplId, Lookup, TraitId, TypeAliasId,
+};
 use hir_expand::name;
 
 use ra_db::salsa::{InternId, InternKey};
 
 use super::{AssocTyValue, Canonical, ChalkContext, Impl, Obligation};
 use crate::{
-    db::HirDatabase,
-    ty::display::HirDisplay,
-    ty::{ApplicationTy, GenericPredicate, ProjectionTy, Substs, TraitRef, Ty, TypeCtor, TypeWalk},
-    Crate, GenericDef, ImplBlock, Trait, TypeAlias,
+    db::HirDatabase, display::HirDisplay, ApplicationTy, GenericPredicate, ImplTy, ProjectionTy,
+    Substs, TraitRef, Ty, TypeCtor, TypeWalk,
 };
 
 /// This represents a trait whose name we could not resolve.
@@ -167,15 +169,15 @@ impl ToChalk for TraitRef {
     }
 }
 
-impl ToChalk for Trait {
+impl ToChalk for TraitId {
     type Chalk = chalk_ir::TraitId;
 
     fn to_chalk(self, _db: &impl HirDatabase) -> chalk_ir::TraitId {
-        chalk_ir::TraitId(id_to_chalk(self.id))
+        chalk_ir::TraitId(id_to_chalk(self))
     }
 
-    fn from_chalk(_db: &impl HirDatabase, trait_id: chalk_ir::TraitId) -> Trait {
-        Trait { id: id_from_chalk(trait_id.0) }
+    fn from_chalk(_db: &impl HirDatabase, trait_id: chalk_ir::TraitId) -> TraitId {
+        id_from_chalk(trait_id.0)
     }
 }
 
@@ -203,15 +205,15 @@ impl ToChalk for Impl {
     }
 }
 
-impl ToChalk for TypeAlias {
+impl ToChalk for TypeAliasId {
     type Chalk = chalk_ir::TypeId;
 
     fn to_chalk(self, _db: &impl HirDatabase) -> chalk_ir::TypeId {
-        chalk_ir::TypeId(id_to_chalk(self.id))
+        chalk_ir::TypeId(id_to_chalk(self))
     }
 
-    fn from_chalk(_db: &impl HirDatabase, type_alias_id: chalk_ir::TypeId) -> TypeAlias {
-        TypeAlias { id: id_from_chalk(type_alias_id.0) }
+    fn from_chalk(_db: &impl HirDatabase, type_alias_id: chalk_ir::TypeId) -> TypeAliasId {
+        id_from_chalk(type_alias_id.0)
     }
 }
 
@@ -402,7 +404,7 @@ fn make_binders<T>(value: T, num_vars: usize) -> chalk_ir::Binders<T> {
 
 fn convert_where_clauses(
     db: &impl HirDatabase,
-    def: GenericDef,
+    def: GenericDefId,
     substs: &Substs,
 ) -> Vec<chalk_ir::QuantifiedWhereClause<ChalkIr>> {
     let generic_predicates = db.generic_predicates(def);
@@ -431,25 +433,25 @@ where
     fn struct_datum(&self, struct_id: chalk_ir::StructId) -> Arc<StructDatum<ChalkIr>> {
         self.db.struct_datum(self.krate, struct_id)
     }
-    fn impl_datum(&self, impl_id: ImplId) -> Arc<ImplDatum<ChalkIr>> {
+    fn impl_datum(&self, impl_id: chalk_ir::ImplId) -> Arc<ImplDatum<ChalkIr>> {
         self.db.impl_datum(self.krate, impl_id)
     }
     fn impls_for_trait(
         &self,
         trait_id: chalk_ir::TraitId,
         parameters: &[Parameter<ChalkIr>],
-    ) -> Vec<ImplId> {
+    ) -> Vec<chalk_ir::ImplId> {
         debug!("impls_for_trait {:?}", trait_id);
         if trait_id == UNKNOWN_TRAIT {
             return Vec::new();
         }
-        let trait_: Trait = from_chalk(self.db, trait_id);
+        let trait_: TraitId = from_chalk(self.db, trait_id);
         let mut result: Vec<_> = self
             .db
-            .impls_for_trait(self.krate, trait_)
+            .impls_for_trait(self.krate, trait_.into())
             .iter()
             .copied()
-            .map(Impl::ImplBlock)
+            .map(|it| Impl::ImplBlock(it.into()))
             .map(|impl_| impl_.to_chalk(self.db))
             .collect();
 
@@ -485,7 +487,7 @@ where
         &self,
         id: chalk_rust_ir::AssociatedTyValueId,
     ) -> Arc<AssociatedTyValue<ChalkIr>> {
-        self.db.associated_ty_value(self.krate, id)
+        self.db.associated_ty_value(self.krate.into(), id)
     }
     fn custom_clauses(&self) -> Vec<chalk_ir::ProgramClause<ChalkIr>> {
         vec![]
@@ -504,12 +506,12 @@ pub(crate) fn associated_ty_data_query(
     id: TypeId,
 ) -> Arc<AssociatedTyDatum<ChalkIr>> {
     debug!("associated_ty_data {:?}", id);
-    let type_alias: TypeAlias = from_chalk(db, id);
-    let trait_ = match type_alias.container(db) {
-        Some(crate::Container::Trait(t)) => t,
+    let type_alias: TypeAliasId = from_chalk(db, id);
+    let trait_ = match type_alias.lookup(db).container {
+        ContainerId::TraitId(t) => t,
         _ => panic!("associated type not in trait"),
     };
-    let generic_params = db.generic_params(type_alias.id.into());
+    let generic_params = db.generic_params(type_alias.into());
     let bound_data = chalk_rust_ir::AssociatedTyDatumBound {
         // FIXME add bounds and where clauses
         bounds: vec![],
@@ -518,7 +520,7 @@ pub(crate) fn associated_ty_data_query(
     let datum = AssociatedTyDatum {
         trait_id: trait_.to_chalk(db),
         id,
-        name: lalrpop_intern::intern(&type_alias.name(db).to_string()),
+        name: lalrpop_intern::intern(&db.type_alias_data(type_alias).name.to_string()),
         binders: make_binders(bound_data, generic_params.count_params_including_parent()),
     };
     Arc::new(datum)
@@ -526,7 +528,7 @@ pub(crate) fn associated_ty_data_query(
 
 pub(crate) fn trait_datum_query(
     db: &impl HirDatabase,
-    krate: Crate,
+    krate: CrateId,
     trait_id: chalk_ir::TraitId,
 ) -> Arc<TraitDatum<ChalkIr>> {
     debug!("trait_datum {:?}", trait_id);
@@ -548,13 +550,14 @@ pub(crate) fn trait_datum_query(
             associated_ty_ids: vec![],
         });
     }
-    let trait_: Trait = from_chalk(db, trait_id);
-    debug!("trait {:?} = {:?}", trait_id, trait_.name(db));
-    let generic_params = db.generic_params(trait_.id.into());
+    let trait_: TraitId = from_chalk(db, trait_id);
+    let trait_data = db.trait_data(trait_);
+    debug!("trait {:?} = {:?}", trait_id, trait_data.name);
+    let generic_params = db.generic_params(trait_.into());
     let bound_vars = Substs::bound_vars(&generic_params);
     let flags = chalk_rust_ir::TraitFlags {
-        auto: trait_.is_auto(db),
-        upstream: trait_.module(db).krate() != krate,
+        auto: trait_data.auto,
+        upstream: trait_.module(db).krate != krate,
         non_enumerable: true,
         coinductive: false, // only relevant for Chalk testing
         // FIXME set these flags correctly
@@ -562,15 +565,8 @@ pub(crate) fn trait_datum_query(
         fundamental: false,
     };
     let where_clauses = convert_where_clauses(db, trait_.into(), &bound_vars);
-    let associated_ty_ids = trait_
-        .items(db)
-        .into_iter()
-        .filter_map(|trait_item| match trait_item {
-            crate::AssocItem::TypeAlias(type_alias) => Some(type_alias),
-            _ => None,
-        })
-        .map(|type_alias| type_alias.to_chalk(db))
-        .collect();
+    let associated_ty_ids =
+        trait_data.associated_types().map(|type_alias| type_alias.to_chalk(db)).collect();
     let trait_datum_bound = chalk_rust_ir::TraitDatumBound { where_clauses };
     let trait_datum = TraitDatum {
         id: trait_id,
@@ -583,7 +579,7 @@ pub(crate) fn trait_datum_query(
 
 pub(crate) fn struct_datum_query(
     db: &impl HirDatabase,
-    krate: Crate,
+    krate: CrateId,
     struct_id: chalk_ir::StructId,
 ) -> Arc<StructDatum<ChalkIr>> {
     debug!("struct_datum {:?}", struct_id);
@@ -615,8 +611,8 @@ pub(crate) fn struct_datum_query(
 
 pub(crate) fn impl_datum_query(
     db: &impl HirDatabase,
-    krate: Crate,
-    impl_id: ImplId,
+    krate: CrateId,
+    impl_id: chalk_ir::ImplId,
 ) -> Arc<ImplDatum<ChalkIr>> {
     let _p = ra_prof::profile("impl_datum");
     debug!("impl_datum {:?}", impl_id);
@@ -630,24 +626,30 @@ pub(crate) fn impl_datum_query(
 
 fn impl_block_datum(
     db: &impl HirDatabase,
-    krate: Crate,
+    krate: CrateId,
+    chalk_id: chalk_ir::ImplId,
     impl_id: ImplId,
-    impl_block: ImplBlock,
 ) -> Option<Arc<ImplDatum<ChalkIr>>> {
-    let generic_params = db.generic_params(impl_block.id.into());
+    let trait_ref = match db.impl_ty(impl_id) {
+        ImplTy::TraitRef(it) => it,
+        ImplTy::Inherent(_) => return None,
+    };
+    let impl_data = db.impl_data(impl_id);
+
+    let generic_params = db.generic_params(impl_id.into());
     let bound_vars = Substs::bound_vars(&generic_params);
-    let trait_ref = impl_block.target_trait_ref(db)?.subst(&bound_vars);
+    let trait_ref = trait_ref.subst(&bound_vars);
     let trait_ = trait_ref.trait_;
-    let impl_type = if impl_block.krate(db) == krate {
+    let impl_type = if impl_id.module(db).krate == krate {
         chalk_rust_ir::ImplType::Local
     } else {
         chalk_rust_ir::ImplType::External
     };
-    let where_clauses = convert_where_clauses(db, impl_block.into(), &bound_vars);
-    let negative = impl_block.is_negative(db);
+    let where_clauses = convert_where_clauses(db, impl_id.into(), &bound_vars);
+    let negative = impl_data.is_negative;
     debug!(
         "impl {:?}: {}{} where {:?}",
-        impl_id,
+        chalk_id,
         if negative { "!" } else { "" },
         trait_ref.display(db),
         where_clauses
@@ -661,16 +663,18 @@ fn impl_block_datum(
     };
 
     let impl_datum_bound = chalk_rust_ir::ImplDatumBound { trait_ref, where_clauses };
-    let associated_ty_value_ids = impl_block
-        .items(db)
-        .into_iter()
+    let trait_data = db.trait_data(trait_);
+    let associated_ty_value_ids = impl_data
+        .items
+        .iter()
         .filter_map(|item| match item {
-            crate::AssocItem::TypeAlias(type_alias) => Some(type_alias),
+            AssocItemId::TypeAliasId(type_alias) => Some(*type_alias),
             _ => None,
         })
-        .filter(|type_alias| {
+        .filter(|&type_alias| {
             // don't include associated types that don't exist in the trait
-            trait_.associated_type_by_name(db, &type_alias.name(db)).is_some()
+            let name = &db.type_alias_data(type_alias).name;
+            trait_data.associated_type_by_name(name).is_some()
         })
         .map(|type_alias| AssocTyValue::TypeAlias(type_alias).to_chalk(db))
         .collect();
@@ -701,7 +705,7 @@ fn invalid_impl_datum() -> Arc<ImplDatum<ChalkIr>> {
 
 fn closure_fn_trait_impl_datum(
     db: &impl HirDatabase,
-    krate: Crate,
+    krate: CrateId,
     data: super::ClosureFnTraitImplData,
 ) -> Option<Arc<ImplDatum<ChalkIr>>> {
     // for some closure |X, Y| -> Z:
@@ -713,10 +717,10 @@ fn closure_fn_trait_impl_datum(
     // and don't want to return a valid value only to find out later that FnOnce
     // is broken
     let fn_once_trait = get_fn_trait(db, krate, super::FnTrait::FnOnce)?;
-    fn_once_trait.associated_type_by_name(db, &name::OUTPUT_TYPE)?;
+    let _output = db.trait_data(fn_once_trait).associated_type_by_name(&name::OUTPUT_TYPE)?;
 
     let num_args: u16 = match &db.body(data.def.into())[data.expr] {
-        crate::expr::Expr::Lambda { args, .. } => args.len() as u16,
+        Expr::Lambda { args, .. } => args.len() as u16,
         _ => {
             log::warn!("closure for closure type {:?} not found", data);
             0
@@ -735,7 +739,7 @@ fn closure_fn_trait_impl_datum(
     let self_ty = Ty::apply_one(TypeCtor::Closure { def: data.def, expr: data.expr }, sig_ty);
 
     let trait_ref = TraitRef {
-        trait_,
+        trait_: trait_.into(),
         substs: Substs::build_for_def(db, trait_).push(self_ty).push(arg_ty).build(),
     };
 
@@ -758,7 +762,7 @@ fn closure_fn_trait_impl_datum(
 
 pub(crate) fn associated_ty_value_query(
     db: &impl HirDatabase,
-    krate: Crate,
+    krate: CrateId,
     id: chalk_rust_ir::AssociatedTyValueId,
 ) -> Arc<chalk_rust_ir::AssociatedTyValue<ChalkIr>> {
     let data: AssocTyValue = from_chalk(db, id);
@@ -774,24 +778,31 @@ pub(crate) fn associated_ty_value_query(
 
 fn type_alias_associated_ty_value(
     db: &impl HirDatabase,
-    _krate: Crate,
-    type_alias: TypeAlias,
+    _krate: CrateId,
+    type_alias: TypeAliasId,
 ) -> Arc<AssociatedTyValue<ChalkIr>> {
-    let impl_block = type_alias.impl_block(db).expect("assoc ty value should be in impl");
-    let impl_id = Impl::ImplBlock(impl_block).to_chalk(db);
-    let trait_ = impl_block
-        .target_trait_ref(db)
-        .expect("assoc ty value should not exist") // we don't return any assoc ty values if the impl'd trait can't be resolved
-        .trait_;
-    let assoc_ty = trait_
-        .associated_type_by_name(db, &type_alias.name(db))
+    let type_alias_data = db.type_alias_data(type_alias);
+    let impl_id = match type_alias.lookup(db).container {
+        ContainerId::ImplId(it) => it,
+        _ => panic!("assoc ty value should be in impl"),
+    };
+
+    let trait_ref = match db.impl_ty(impl_id) {
+        ImplTy::TraitRef(it) => it,
+        // we don't return any assoc ty values if the impl'd trait can't be resolved
+        ImplTy::Inherent(_) => panic!("assoc ty value should not exist"),
+    };
+
+    let assoc_ty = db
+        .trait_data(trait_ref.trait_)
+        .associated_type_by_name(&type_alias_data.name)
         .expect("assoc ty value should not exist"); // validated when building the impl data as well
-    let generic_params = db.generic_params(impl_block.id.into());
+    let generic_params = db.generic_params(impl_id.into());
     let bound_vars = Substs::bound_vars(&generic_params);
-    let ty = db.type_for_def(type_alias.into(), crate::ty::Namespace::Types).subst(&bound_vars);
+    let ty = db.ty(type_alias.into()).subst(&bound_vars);
     let value_bound = chalk_rust_ir::AssociatedTyValueBound { ty: ty.to_chalk(db) };
     let value = chalk_rust_ir::AssociatedTyValue {
-        impl_id,
+        impl_id: Impl::ImplBlock(impl_id.into()).to_chalk(db),
         associated_ty_id: assoc_ty.to_chalk(db),
         value: make_binders(value_bound, bound_vars.len()),
     };
@@ -800,13 +811,13 @@ fn type_alias_associated_ty_value(
 
 fn closure_fn_trait_output_assoc_ty_value(
     db: &impl HirDatabase,
-    krate: Crate,
+    krate: CrateId,
     data: super::ClosureFnTraitImplData,
 ) -> Arc<AssociatedTyValue<ChalkIr>> {
     let impl_id = Impl::ClosureFnTraitImpl(data.clone()).to_chalk(db);
 
     let num_args: u16 = match &db.body(data.def.into())[data.expr] {
-        crate::expr::Expr::Lambda { args, .. } => args.len() as u16,
+        Expr::Lambda { args, .. } => args.len() as u16,
         _ => {
             log::warn!("closure for closure type {:?} not found", data);
             0
@@ -818,8 +829,9 @@ fn closure_fn_trait_output_assoc_ty_value(
     let fn_once_trait =
         get_fn_trait(db, krate, super::FnTrait::FnOnce).expect("assoc ty value should not exist");
 
-    let output_ty_id = fn_once_trait
-        .associated_type_by_name(db, &name::OUTPUT_TYPE)
+    let output_ty_id = db
+        .trait_data(fn_once_trait)
+        .associated_type_by_name(&name::OUTPUT_TYPE)
         .expect("assoc ty value should not exist");
 
     let value_bound = chalk_rust_ir::AssociatedTyValueBound { ty: output_ty.to_chalk(db) };
@@ -832,10 +844,14 @@ fn closure_fn_trait_output_assoc_ty_value(
     Arc::new(value)
 }
 
-fn get_fn_trait(db: &impl HirDatabase, krate: Crate, fn_trait: super::FnTrait) -> Option<Trait> {
-    let target = db.lang_item(krate.crate_id, fn_trait.lang_item_name().into())?;
+fn get_fn_trait(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    fn_trait: super::FnTrait,
+) -> Option<TraitId> {
+    let target = db.lang_item(krate, fn_trait.lang_item_name().into())?;
     match target {
-        LangItemTarget::TraitId(t) => Some(t.into()),
+        LangItemTarget::TraitId(t) => Some(t),
         _ => None,
     }
 }
@@ -847,38 +863,38 @@ fn id_to_chalk<T: InternKey>(salsa_id: T) -> chalk_ir::RawId {
     chalk_ir::RawId { index: salsa_id.as_intern_id().as_u32() }
 }
 
-impl From<chalk_ir::StructId> for crate::ty::TypeCtorId {
+impl From<chalk_ir::StructId> for crate::TypeCtorId {
     fn from(struct_id: chalk_ir::StructId) -> Self {
         id_from_chalk(struct_id.0)
     }
 }
 
-impl From<crate::ty::TypeCtorId> for chalk_ir::StructId {
-    fn from(type_ctor_id: crate::ty::TypeCtorId) -> Self {
+impl From<crate::TypeCtorId> for chalk_ir::StructId {
+    fn from(type_ctor_id: crate::TypeCtorId) -> Self {
         chalk_ir::StructId(id_to_chalk(type_ctor_id))
     }
 }
 
-impl From<chalk_ir::ImplId> for crate::ty::traits::GlobalImplId {
+impl From<chalk_ir::ImplId> for crate::traits::GlobalImplId {
     fn from(impl_id: chalk_ir::ImplId) -> Self {
         id_from_chalk(impl_id.0)
     }
 }
 
-impl From<crate::ty::traits::GlobalImplId> for chalk_ir::ImplId {
-    fn from(impl_id: crate::ty::traits::GlobalImplId) -> Self {
+impl From<crate::traits::GlobalImplId> for chalk_ir::ImplId {
+    fn from(impl_id: crate::traits::GlobalImplId) -> Self {
         chalk_ir::ImplId(id_to_chalk(impl_id))
     }
 }
 
-impl From<chalk_rust_ir::AssociatedTyValueId> for crate::ty::traits::AssocTyValueId {
+impl From<chalk_rust_ir::AssociatedTyValueId> for crate::traits::AssocTyValueId {
     fn from(id: chalk_rust_ir::AssociatedTyValueId) -> Self {
         id_from_chalk(id.0)
     }
 }
 
-impl From<crate::ty::traits::AssocTyValueId> for chalk_rust_ir::AssociatedTyValueId {
-    fn from(assoc_ty_value_id: crate::ty::traits::AssocTyValueId) -> Self {
+impl From<crate::traits::AssocTyValueId> for chalk_rust_ir::AssociatedTyValueId {
+    fn from(assoc_ty_value_id: crate::traits::AssocTyValueId) -> Self {
         chalk_rust_ir::AssociatedTyValueId(id_to_chalk(assoc_ty_value_id))
     }
 }
diff --git a/crates/ra_hir_ty/src/utils.rs b/crates/ra_hir_ty/src/utils.rs
new file mode 100644
index 000000000..e4ba890ef
--- /dev/null
+++ b/crates/ra_hir_ty/src/utils.rs
@@ -0,0 +1,84 @@
+//! Helper functions for working with def, which don't need to be a separate
+//! query, but can't be computed directly from `*Data` (ie, which need a `db`).
+use std::sync::Arc;
+
+use hir_def::{
+    adt::VariantData,
+    db::DefDatabase,
+    resolver::{HasResolver, TypeNs},
+    type_ref::TypeRef,
+    TraitId, TypeAliasId, VariantId,
+};
+use hir_expand::name::{self, Name};
+
+// FIXME: this is wrong, b/c it can't express `trait T: PartialEq<()>`.
+// We should return a `TraitREf` here.
+fn direct_super_traits(db: &impl DefDatabase, trait_: TraitId) -> Vec<TraitId> {
+    let resolver = trait_.resolver(db);
+    // returning the iterator directly doesn't easily work because of
+    // lifetime problems, but since there usually shouldn't be more than a
+    // few direct traits this should be fine (we could even use some kind of
+    // SmallVec if performance is a concern)
+    db.generic_params(trait_.into())
+        .where_predicates
+        .iter()
+        .filter_map(|pred| match &pred.type_ref {
+            TypeRef::Path(p) if p.as_ident() == Some(&name::SELF_TYPE) => pred.bound.as_path(),
+            _ => None,
+        })
+        .filter_map(|path| match resolver.resolve_path_in_type_ns_fully(db, path) {
+            Some(TypeNs::TraitId(t)) => Some(t),
+            _ => None,
+        })
+        .collect()
+}
+
+/// Returns an iterator over the whole super trait hierarchy (including the
+/// trait itself).
+pub(super) fn all_super_traits(db: &impl DefDatabase, trait_: TraitId) -> Vec<TraitId> {
+    // we need to take care a bit here to avoid infinite loops in case of cycles
+    // (i.e. if we have `trait A: B; trait B: A;`)
+    let mut result = vec![trait_];
+    let mut i = 0;
+    while i < result.len() {
+        let t = result[i];
+        // yeah this is quadratic, but trait hierarchies should be flat
+        // enough that this doesn't matter
+        for tt in direct_super_traits(db, t) {
+            if !result.contains(&tt) {
+                result.push(tt);
+            }
+        }
+        i += 1;
+    }
+    result
+}
+
+pub(super) fn associated_type_by_name_including_super_traits(
+    db: &impl DefDatabase,
+    trait_: TraitId,
+    name: &Name,
+) -> Option<TypeAliasId> {
+    all_super_traits(db, trait_)
+        .into_iter()
+        .find_map(|t| db.trait_data(t).associated_type_by_name(name))
+}
+
+pub(super) fn variant_data(db: &impl DefDatabase, var: VariantId) -> Arc<VariantData> {
+    match var {
+        VariantId::StructId(it) => db.struct_data(it).variant_data.clone(),
+        VariantId::UnionId(it) => db.union_data(it).variant_data.clone(),
+        VariantId::EnumVariantId(it) => {
+            db.enum_data(it.parent).variants[it.local_id].variant_data.clone()
+        }
+    }
+}
+
+/// Helper for mutating `Arc<[T]>` (i.e. `Arc::make_mut` for Arc slices).
+/// The underlying values are cloned if there are other strong references.
+pub(crate) fn make_mut_slice<T: Clone>(a: &mut Arc<[T]>) -> &mut [T] {
+    if Arc::get_mut(a).is_none() {
+        *a = a.iter().cloned().collect();
+    }
+    Arc::get_mut(a).unwrap()
+}
diff --git a/crates/ra_ide_api/Cargo.toml b/crates/ra_ide/Cargo.toml
index 15346f388..e6383dd35 100644
--- a/crates/ra_ide_api/Cargo.toml
+++ b/crates/ra_ide/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 edition = "2018"
-name = "ra_ide_api"
+name = "ra_ide"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
 
@@ -32,7 +32,7 @@ ra_prof = { path = "../ra_prof" }
 test_utils = { path = "../test_utils" }
 ra_assists = { path = "../ra_assists" }
 
-# ra_ide_api should depend only on the top-level `hir` package. if you need
+# ra_ide should depend only on the top-level `hir` package. if you need
 # something from some `hir_xxx` subpackage, reexport the API via `hir`.
 hir = { path = "../ra_hir", package = "ra_hir" }
 
diff --git a/crates/ra_ide_api/src/assists.rs b/crates/ra_ide/src/assists.rs
index e00589733..e00589733 100644
--- a/crates/ra_ide_api/src/assists.rs
+++ b/crates/ra_ide/src/assists.rs
diff --git a/crates/ra_ide_api/src/call_info.rs b/crates/ra_ide/src/call_info.rs
index 7c367230e..d559dc4d0 100644
--- a/crates/ra_ide_api/src/call_info.rs
+++ b/crates/ra_ide/src/call_info.rs
@@ -18,22 +18,22 @@ pub(crate) fn call_info(db: &RootDatabase, position: FilePosition) -> Option<Cal
     // Find the calling expression and it's NameRef
     let calling_node = FnCallNode::with_node(&syntax, position.offset)?;
     let name_ref = calling_node.name_ref()?;
+    let name_ref = hir::Source::new(position.file_id.into(), name_ref.syntax());
 
-    let analyzer = hir::SourceAnalyzer::new(
-        db,
-        hir::Source::new(position.file_id.into(), name_ref.syntax()),
-        None,
-    );
+    let analyzer = hir::SourceAnalyzer::new(db, name_ref, None);
     let (mut call_info, has_self) = match &calling_node {
         FnCallNode::CallExpr(expr) => {
-            //FIXME: apply subst
-            let (callable_def, _subst) = analyzer.type_of(db, &expr.expr()?)?.as_callable()?;
+            //FIXME: Type::as_callable is broken
+            let callable_def = analyzer.type_of(db, &expr.expr()?)?.as_callable()?;
             match callable_def {
-                hir::CallableDef::Function(it) => {
-                    (CallInfo::with_fn(db, it), it.has_self_param(db))
+                hir::CallableDef::FunctionId(it) => {
+                    let fn_def = it.into();
+                    (CallInfo::with_fn(db, fn_def), fn_def.has_self_param(db))
+                }
+                hir::CallableDef::StructId(it) => (CallInfo::with_struct(db, it.into())?, false),
+                hir::CallableDef::EnumVariantId(it) => {
+                    (CallInfo::with_enum_variant(db, it.into())?, false)
                 }
-                hir::CallableDef::Struct(it) => (CallInfo::with_struct(db, it)?, false),
-                hir::CallableDef::EnumVariant(it) => (CallInfo::with_enum_variant(db, it)?, false),
             }
         }
         FnCallNode::MethodCallExpr(expr) => {
@@ -41,7 +41,7 @@ pub(crate) fn call_info(db: &RootDatabase, position: FilePosition) -> Option<Cal
             (CallInfo::with_fn(db, function), function.has_self_param(db))
         }
         FnCallNode::MacroCallExpr(expr) => {
-            let macro_def = analyzer.resolve_macro_call(db, &expr)?;
+            let macro_def = analyzer.resolve_macro_call(db, name_ref.with_value(&expr))?;
             (CallInfo::with_macro(db, macro_def)?, false)
         }
     };
diff --git a/crates/ra_ide_api/src/change.rs b/crates/ra_ide/src/change.rs
index 0f692460d..4a76d1dd8 100644
--- a/crates/ra_ide_api/src/change.rs
+++ b/crates/ra_ide/src/change.rs
@@ -171,7 +171,7 @@ impl RootDatabase {
         log::info!("apply_change {:?}", change);
         {
             let _p = profile("RootDatabase::apply_change/cancellation");
-            self.salsa_runtime().synthetic_write(Durability::LOW);
+            self.salsa_runtime_mut().synthetic_write(Durability::LOW);
         }
         if !change.new_roots.is_empty() {
             let mut local_roots = Vec::clone(&self.local_roots());
@@ -323,7 +323,8 @@ impl RootDatabase {
             hir::db::DocumentationQuery
             hir::db::ExprScopesQuery
             hir::db::InferQuery
-            hir::db::TypeForDefQuery
+            hir::db::TyQuery
+            hir::db::ValueTyQuery
             hir::db::FieldTypesQuery
             hir::db::CallableItemSignatureQuery
             hir::db::GenericPredicatesQuery
diff --git a/crates/ra_ide_api/src/completion.rs b/crates/ra_ide/src/completion.rs
index abe1f36ce..abe1f36ce 100644
--- a/crates/ra_ide_api/src/completion.rs
+++ b/crates/ra_ide/src/completion.rs
diff --git a/crates/ra_ide_api/src/completion/complete_dot.rs b/crates/ra_ide/src/completion/complete_dot.rs
index 5a3f9b5f6..b6fe48627 100644
--- a/crates/ra_ide_api/src/completion/complete_dot.rs
+++ b/crates/ra_ide/src/completion/complete_dot.rs
@@ -1,6 +1,6 @@
 //! FIXME: write short doc here
 
-use hir::{Adt, Ty, TypeCtor};
+use hir::Type;
 
 use crate::completion::completion_item::CompletionKind;
 use crate::{
@@ -22,12 +22,12 @@ pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
     };
 
     if !ctx.is_call {
-        complete_fields(acc, ctx, receiver_ty.clone());
+        complete_fields(acc, ctx, &receiver_ty);
     }
-    complete_methods(acc, ctx, receiver_ty.clone());
+    complete_methods(acc, ctx, &receiver_ty);
 
     // Suggest .await syntax for types that implement Future trait
-    if ctx.analyzer.impls_future(ctx.db, receiver_ty) {
+    if ctx.analyzer.impls_future(ctx.db, receiver_ty.into_ty()) {
         CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await")
             .detail("expr.await")
             .insert_text("await")
@@ -35,28 +35,18 @@ pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
     }
 }
 
-fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: Ty) {
-    for receiver in ctx.analyzer.autoderef(ctx.db, receiver) {
-        if let Ty::Apply(a_ty) = receiver {
-            match a_ty.ctor {
-                TypeCtor::Adt(Adt::Struct(s)) => {
-                    for field in s.fields(ctx.db) {
-                        acc.add_field(ctx, field, &a_ty.parameters);
-                    }
-                }
-                // FIXME unions
-                TypeCtor::Tuple { .. } => {
-                    for (i, ty) in a_ty.parameters.iter().enumerate() {
-                        acc.add_tuple_field(ctx, i, ty);
-                    }
-                }
-                _ => {}
-            }
-        };
+fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
+    for receiver in receiver.autoderef(ctx.db) {
+        for (field, ty) in receiver.fields(ctx.db) {
+            acc.add_field(ctx, field, &ty);
+        }
+        for (i, ty) in receiver.tuple_fields(ctx.db).into_iter().enumerate() {
+            acc.add_tuple_field(ctx, i, &ty);
+        }
     }
 }
 
-fn complete_methods(acc: &mut Completions, ctx: &CompletionContext, receiver: Ty) {
+fn complete_methods(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
     let mut seen_methods = FxHashSet::default();
     ctx.analyzer.iterate_method_candidates(ctx.db, receiver, None, |_ty, func| {
         if func.has_self_param(ctx.db) && seen_methods.insert(func.name(ctx.db)) {
diff --git a/crates/ra_ide_api/src/completion/complete_fn_param.rs b/crates/ra_ide/src/completion/complete_fn_param.rs
index 502458706..502458706 100644
--- a/crates/ra_ide_api/src/completion/complete_fn_param.rs
+++ b/crates/ra_ide/src/completion/complete_fn_param.rs
diff --git a/crates/ra_ide_api/src/completion/complete_keyword.rs b/crates/ra_ide/src/completion/complete_keyword.rs
index eb7cd9ac2..eb7cd9ac2 100644
--- a/crates/ra_ide_api/src/completion/complete_keyword.rs
+++ b/crates/ra_ide/src/completion/complete_keyword.rs
diff --git a/crates/ra_ide_api/src/completion/complete_macro_in_item_position.rs b/crates/ra_ide/src/completion/complete_macro_in_item_position.rs
index faadd1e3f..faadd1e3f 100644
--- a/crates/ra_ide_api/src/completion/complete_macro_in_item_position.rs
+++ b/crates/ra_ide/src/completion/complete_macro_in_item_position.rs
diff --git a/crates/ra_ide_api/src/completion/complete_path.rs b/crates/ra_ide/src/completion/complete_path.rs
index 63e25e0bf..89e0009a1 100644
--- a/crates/ra_ide_api/src/completion/complete_path.rs
+++ b/crates/ra_ide/src/completion/complete_path.rs
@@ -50,7 +50,7 @@ pub(super) fn complete_path(acc: &mut Completions, ctx: &CompletionContext) {
                 hir::ModuleDef::TypeAlias(a) => a.ty(ctx.db),
                 _ => unreachable!(),
             };
-            ctx.analyzer.iterate_path_candidates(ctx.db, ty.clone(), None, |_ty, item| {
+            ctx.analyzer.iterate_path_candidates(ctx.db, &ty, None, |_ty, item| {
                 match item {
                     hir::AssocItem::Function(func) => {
                         if !func.has_self_param(ctx.db) {
diff --git a/crates/ra_ide_api/src/completion/complete_pattern.rs b/crates/ra_ide/src/completion/complete_pattern.rs
index fd03b1c40..fd03b1c40 100644
--- a/crates/ra_ide_api/src/completion/complete_pattern.rs
+++ b/crates/ra_ide/src/completion/complete_pattern.rs
diff --git a/crates/ra_ide_api/src/completion/complete_postfix.rs b/crates/ra_ide/src/completion/complete_postfix.rs
index 17b75cf7e..646a30c76 100644
--- a/crates/ra_ide_api/src/completion/complete_postfix.rs
+++ b/crates/ra_ide/src/completion/complete_postfix.rs
@@ -1,6 +1,5 @@
 //! FIXME: write short doc here
 
-use hir::{Ty, TypeCtor};
 use ra_syntax::{ast::AstNode, TextRange, TextUnit};
 use ra_text_edit::TextEdit;
 
@@ -30,9 +29,12 @@ pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
         dot_receiver.syntax().text().to_string()
     };
 
-    let receiver_ty = ctx.analyzer.type_of(ctx.db, &dot_receiver);
+    let receiver_ty = match ctx.analyzer.type_of(ctx.db, &dot_receiver) {
+        Some(it) => it,
+        None => return,
+    };
 
-    if is_bool_or_unknown(receiver_ty) {
+    if receiver_ty.is_bool() || receiver_ty.is_unknown() {
         postfix_snippet(ctx, "if", "if expr {}", &format!("if {} {{$0}}", receiver_text))
             .add_to(acc);
         postfix_snippet(
@@ -75,14 +77,6 @@ fn postfix_snippet(ctx: &CompletionContext, label: &str, detail: &str, snippet:
         .snippet_edit(edit)
 }
 
-fn is_bool_or_unknown(ty: Option<Ty>) -> bool {
-    match &ty {
-        Some(Ty::Apply(app)) if app.ctor == TypeCtor::Bool => true,
-        Some(Ty::Unknown) | None => true,
-        Some(_) => false,
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use insta::assert_debug_snapshot;
diff --git a/crates/ra_ide_api/src/completion/complete_record_literal.rs b/crates/ra_ide/src/completion/complete_record_literal.rs
index 45a4a9738..577c394d2 100644
--- a/crates/ra_ide_api/src/completion/complete_record_literal.rs
+++ b/crates/ra_ide/src/completion/complete_record_literal.rs
@@ -1,7 +1,5 @@
 //! FIXME: write short doc here
 
-use hir::Substs;
-
 use crate::completion::{CompletionContext, Completions};
 
 /// Complete fields in fields literals.
@@ -15,10 +13,9 @@ pub(super) fn complete_record_literal(acc: &mut Completions, ctx: &CompletionCon
         Some(it) => it,
         _ => return,
     };
-    let substs = &ty.substs().unwrap_or_else(Substs::empty);
 
-    for field in variant.fields(ctx.db) {
-        acc.add_field(ctx, field, substs);
+    for (field, field_ty) in ty.variant_fields(ctx.db, variant) {
+        acc.add_field(ctx, field, &field_ty);
     }
 }
 
diff --git a/crates/ra_ide_api/src/completion/complete_record_pattern.rs b/crates/ra_ide/src/completion/complete_record_pattern.rs
index aa0fd6d24..a56c7e3a1 100644
--- a/crates/ra_ide_api/src/completion/complete_record_pattern.rs
+++ b/crates/ra_ide/src/completion/complete_record_pattern.rs
@@ -1,7 +1,5 @@
 //! FIXME: write short doc here
 
-use hir::Substs;
-
 use crate::completion::{CompletionContext, Completions};
 
 pub(super) fn complete_record_pattern(acc: &mut Completions, ctx: &CompletionContext) {
@@ -14,10 +12,9 @@ pub(super) fn complete_record_pattern(acc: &mut Completions, ctx: &CompletionCon
         Some(it) => it,
         _ => return,
     };
-    let substs = &ty.substs().unwrap_or_else(Substs::empty);
 
-    for field in variant.fields(ctx.db) {
-        acc.add_field(ctx, field, substs);
+    for (field, field_ty) in ty.variant_fields(ctx.db, variant) {
+        acc.add_field(ctx, field, &field_ty);
     }
 }
 
diff --git a/crates/ra_ide_api/src/completion/complete_scope.rs b/crates/ra_ide/src/completion/complete_scope.rs
index d5739b58a..d5739b58a 100644
--- a/crates/ra_ide_api/src/completion/complete_scope.rs
+++ b/crates/ra_ide/src/completion/complete_scope.rs
diff --git a/crates/ra_ide_api/src/completion/complete_snippet.rs b/crates/ra_ide/src/completion/complete_snippet.rs
index 1f2988b36..1f2988b36 100644
--- a/crates/ra_ide_api/src/completion/complete_snippet.rs
+++ b/crates/ra_ide/src/completion/complete_snippet.rs
diff --git a/crates/ra_ide_api/src/completion/completion_context.rs b/crates/ra_ide/src/completion/completion_context.rs
index b8345c91d..b8345c91d 100644
--- a/crates/ra_ide_api/src/completion/completion_context.rs
+++ b/crates/ra_ide/src/completion/completion_context.rs
diff --git a/crates/ra_ide_api/src/completion/completion_item.rs b/crates/ra_ide/src/completion/completion_item.rs
index 93f336370..93f336370 100644
--- a/crates/ra_ide_api/src/completion/completion_item.rs
+++ b/crates/ra_ide/src/completion/completion_item.rs
diff --git a/crates/ra_ide_api/src/completion/presentation.rs b/crates/ra_ide/src/completion/presentation.rs
index bac3f7582..97475fc0b 100644
--- a/crates/ra_ide_api/src/completion/presentation.rs
+++ b/crates/ra_ide/src/completion/presentation.rs
@@ -1,12 +1,12 @@
 //! This modules takes care of rendering various definitions as completion items.
 
-use hir::{db::HirDatabase, Docs, HasAttrs, HasSource, HirDisplay, ScopeDef, Ty, TypeWalk};
+use hir::{db::HirDatabase, Docs, HasAttrs, HasSource, HirDisplay, ScopeDef, Type};
 use join_to_string::join;
 use ra_syntax::ast::NameOwner;
 use test_utils::tested_by;
 
 use crate::completion::{
-    db, CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions,
+    CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions,
 };
 
 use crate::display::{const_label, function_label, macro_label, type_label};
@@ -16,7 +16,7 @@ impl Completions {
         &mut self,
         ctx: &CompletionContext,
         field: hir::StructField,
-        substs: &hir::Substs,
+        ty: &Type,
     ) {
         let is_deprecated = is_deprecated(field, ctx.db);
         CompletionItem::new(
@@ -25,13 +25,13 @@ impl Completions {
             field.name(ctx.db).to_string(),
         )
         .kind(CompletionItemKind::Field)
-        .detail(field.ty(ctx.db).subst(substs).display(ctx.db).to_string())
+        .detail(ty.display(ctx.db).to_string())
         .set_documentation(field.docs(ctx.db))
         .set_deprecated(is_deprecated)
         .add_to(self);
     }
 
-    pub(crate) fn add_tuple_field(&mut self, ctx: &CompletionContext, field: usize, ty: &hir::Ty) {
+    pub(crate) fn add_tuple_field(&mut self, ctx: &CompletionContext, field: usize, ty: &Type) {
         CompletionItem::new(CompletionKind::Reference, ctx.source_range(), field.to_string())
             .kind(CompletionItemKind::Field)
             .detail(ty.display(ctx.db).to_string())
@@ -98,7 +98,7 @@ impl Completions {
             CompletionItem::new(completion_kind, ctx.source_range(), local_name.clone());
         if let ScopeDef::Local(local) = resolution {
             let ty = local.ty(ctx.db);
-            if ty != Ty::Unknown {
+            if !ty.is_unknown() {
                 completion_item = completion_item.detail(ty.display(ctx.db).to_string());
             }
         };
@@ -108,19 +108,17 @@ impl Completions {
             && !ctx.has_type_args
             && ctx.db.feature_flags.get("completion.insertion.add-call-parenthesis")
         {
-            let generic_def: Option<hir::GenericDef> = match resolution {
-                ScopeDef::ModuleDef(Adt(it)) => Some((*it).into()),
-                ScopeDef::ModuleDef(TypeAlias(it)) => Some((*it).into()),
-                _ => None,
+            let has_non_default_type_params = match resolution {
+                ScopeDef::ModuleDef(Adt(it)) => it.has_non_default_type_params(ctx.db),
+                ScopeDef::ModuleDef(TypeAlias(it)) => it.has_non_default_type_params(ctx.db),
+                _ => false,
             };
-            if let Some(def) = generic_def {
-                if has_non_default_type_params(def, ctx.db) {
-                    tested_by!(inserts_angle_brackets_for_generics);
-                    completion_item = completion_item
-                        .lookup_by(local_name.clone())
-                        .label(format!("{}<…>", local_name))
-                        .insert_snippet(format!("{}<$0>", local_name));
-                }
+            if has_non_default_type_params {
+                tested_by!(inserts_angle_brackets_for_generics);
+                completion_item = completion_item
+                    .lookup_by(local_name.clone())
+                    .label(format!("{}<…>", local_name))
+                    .insert_snippet(format!("{}<$0>", local_name));
             }
         }
 
@@ -269,10 +267,7 @@ impl Completions {
 
     pub(crate) fn add_enum_variant(&mut self, ctx: &CompletionContext, variant: hir::EnumVariant) {
         let is_deprecated = is_deprecated(variant, ctx.db);
-        let name = match variant.name(ctx.db) {
-            Some(it) => it,
-            None => return,
-        };
+        let name = variant.name(ctx.db);
         let detail_types = variant.fields(ctx.db).into_iter().map(|field| field.ty(ctx.db));
         let detail = join(detail_types.map(|t| t.display(ctx.db).to_string()))
             .separator(", ")
@@ -291,11 +286,6 @@ fn is_deprecated(node: impl HasAttrs, db: &impl HirDatabase) -> bool {
     node.attrs(db).by_key("deprecated").exists()
 }
 
-fn has_non_default_type_params(def: hir::GenericDef, db: &db::RootDatabase) -> bool {
-    let subst = db.generic_defaults(def);
-    subst.iter().any(|ty| ty == &Ty::Unknown)
-}
-
 #[cfg(test)]
 mod tests {
     use insta::assert_debug_snapshot;
diff --git a/crates/ra_ide_api/src/db.rs b/crates/ra_ide/src/db.rs
index c2a9dcdd1..f739ebecd 100644
--- a/crates/ra_ide_api/src/db.rs
+++ b/crates/ra_ide/src/db.rs
@@ -65,6 +65,9 @@ impl salsa::Database for RootDatabase {
     fn salsa_runtime(&self) -> &salsa::Runtime<RootDatabase> {
         &self.runtime
     }
+    fn salsa_runtime_mut(&mut self) -> &mut salsa::Runtime<Self> {
+        &mut self.runtime
+    }
     fn on_propagated_panic(&self) -> ! {
         Canceled::throw()
     }
diff --git a/crates/ra_ide_api/src/diagnostics.rs b/crates/ra_ide/src/diagnostics.rs
index cc1ccab4b..cc1ccab4b 100644
--- a/crates/ra_ide_api/src/diagnostics.rs
+++ b/crates/ra_ide/src/diagnostics.rs
diff --git a/crates/ra_ide_api/src/display.rs b/crates/ra_ide/src/display.rs
index 30617412a..30617412a 100644
--- a/crates/ra_ide_api/src/display.rs
+++ b/crates/ra_ide/src/display.rs
diff --git a/crates/ra_ide_api/src/display/function_signature.rs b/crates/ra_ide/src/display/function_signature.rs
index d96de4e4c..324ad9552 100644
--- a/crates/ra_ide_api/src/display/function_signature.rs
+++ b/crates/ra_ide/src/display/function_signature.rs
@@ -93,12 +93,9 @@ impl FunctionSignature {
             _ => (),
         };
 
-        let parent_name = match variant.parent_enum(db).name(db) {
-            Some(name) => name.to_string(),
-            None => "missing".into(),
-        };
+        let parent_name = variant.parent_enum(db).name(db).to_string();
 
-        let name = format!("{}::{}", parent_name, variant.name(db).unwrap());
+        let name = format!("{}::{}", parent_name, variant.name(db));
 
         let params = variant
             .fields(db)
diff --git a/crates/ra_ide_api/src/display/navigation_target.rs b/crates/ra_ide/src/display/navigation_target.rs
index 6ac60722b..6ac60722b 100644
--- a/crates/ra_ide_api/src/display/navigation_target.rs
+++ b/crates/ra_ide/src/display/navigation_target.rs
diff --git a/crates/ra_ide_api/src/display/short_label.rs b/crates/ra_ide/src/display/short_label.rs
index 5d2bce3d2..9ffc9b980 100644
--- a/crates/ra_ide_api/src/display/short_label.rs
+++ b/crates/ra_ide/src/display/short_label.rs
@@ -19,6 +19,12 @@ impl ShortLabel for ast::StructDef {
     }
 }
 
+impl ShortLabel for ast::UnionDef {
+    fn short_label(&self) -> Option<String> {
+        short_label_from_node(self, "union ")
+    }
+}
+
 impl ShortLabel for ast::EnumDef {
     fn short_label(&self) -> Option<String> {
         short_label_from_node(self, "enum ")
diff --git a/crates/ra_ide_api/src/display/structure.rs b/crates/ra_ide/src/display/structure.rs
index a80d65ac7..a80d65ac7 100644
--- a/crates/ra_ide_api/src/display/structure.rs
+++ b/crates/ra_ide/src/display/structure.rs
diff --git a/crates/ra_ide_api/src/expand.rs b/crates/ra_ide/src/expand.rs
index 2f1abf509..2f1abf509 100644
--- a/crates/ra_ide_api/src/expand.rs
+++ b/crates/ra_ide/src/expand.rs
diff --git a/crates/ra_ide_api/src/expand_macro.rs b/crates/ra_ide/src/expand_macro.rs
index 0b540b8cd..abc602244 100644
--- a/crates/ra_ide_api/src/expand_macro.rs
+++ b/crates/ra_ide/src/expand_macro.rs
@@ -269,4 +269,27 @@ fn some_thing() -> u32 {
         assert_eq!(res.name, "foo");
         assert_snapshot!(res.expansion, @r###"bar!()"###);
     }
+
+    #[test]
+    fn macro_expand_with_dollar_crate() {
+        let res = check_expand_macro(
+            r#"
+        //- /lib.rs
+        #[macro_export]
+        macro_rules! bar {
+            () => {0};
+        }
+        macro_rules! foo {
+            () => {$crate::bar!()};
+        }        
+
+        fn main() {        
+            let res = fo<|>o!();
+        }
+        "#,
+        );
+
+        assert_eq!(res.name, "foo");
+        assert_snapshot!(res.expansion, @r###"0"###);
+    }
 }
diff --git a/crates/ra_ide_api/src/extend_selection.rs b/crates/ra_ide/src/extend_selection.rs
index 4b7bfc0b1..4b7bfc0b1 100644
--- a/crates/ra_ide_api/src/extend_selection.rs
+++ b/crates/ra_ide/src/extend_selection.rs
diff --git a/crates/ra_ide_api/src/feature_flags.rs b/crates/ra_ide/src/feature_flags.rs
index de4ae513d..de4ae513d 100644
--- a/crates/ra_ide_api/src/feature_flags.rs
+++ b/crates/ra_ide/src/feature_flags.rs
diff --git a/crates/ra_ide_api/src/folding_ranges.rs b/crates/ra_ide/src/folding_ranges.rs
index 4eeb76d14..4eeb76d14 100644
--- a/crates/ra_ide_api/src/folding_ranges.rs
+++ b/crates/ra_ide/src/folding_ranges.rs
diff --git a/crates/ra_ide_api/src/goto_definition.rs b/crates/ra_ide/src/goto_definition.rs
index b6c72efdf..c10a6c844 100644
--- a/crates/ra_ide_api/src/goto_definition.rs
+++ b/crates/ra_ide/src/goto_definition.rs
@@ -71,10 +71,11 @@ pub(crate) fn reference_definition(
             Some(nav) => return Exact(nav),
             None => return Approximate(vec![]),
         },
-        Some(SelfType(ty)) => {
-            if let Some((adt, _)) = ty.as_adt() {
-                return Exact(adt.to_nav(db));
-            }
+        Some(SelfType(imp)) => {
+            // FIXME: ideally, this should point to the type in the impl, and
+            // not at the whole impl. And goto **type** definition should bring
+            // us to the actual type
+            return Exact(imp.to_nav(db));
         }
         Some(Local(local)) => return Exact(local.to_nav(db)),
         Some(GenericParam(_)) => {
@@ -503,7 +504,7 @@ mod tests {
                 }
             }
             ",
-            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+            "impl IMPL_BLOCK FileId(1) [12; 73)",
         );
 
         check_goto(
@@ -516,7 +517,7 @@ mod tests {
                 }
             }
             ",
-            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+            "impl IMPL_BLOCK FileId(1) [12; 73)",
         );
 
         check_goto(
@@ -529,7 +530,7 @@ mod tests {
                 }
             }
             ",
-            "Foo ENUM_DEF FileId(1) [0; 14) [5; 8)",
+            "impl IMPL_BLOCK FileId(1) [15; 75)",
         );
 
         check_goto(
@@ -541,7 +542,7 @@ mod tests {
                 }
             }
             ",
-            "Foo ENUM_DEF FileId(1) [0; 14) [5; 8)",
+            "impl IMPL_BLOCK FileId(1) [15; 62)",
         );
     }
 
@@ -560,7 +561,7 @@ mod tests {
                 }
             }
             ",
-            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+            "impl IMPL_BLOCK FileId(1) [49; 115)",
         );
 
         check_goto(
@@ -572,11 +573,11 @@ mod tests {
             }
             impl Make for Foo {
                 fn new() -> Self<|> {
-                    Self{}
+                    Self {}
                 }
             }
             ",
-            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+            "impl IMPL_BLOCK FileId(1) [49; 115)",
         );
     }
 
diff --git a/crates/ra_ide_api/src/goto_type_definition.rs b/crates/ra_ide/src/goto_type_definition.rs
index 28a83a3e2..992a08809 100644
--- a/crates/ra_ide_api/src/goto_type_definition.rs
+++ b/crates/ra_ide/src/goto_type_definition.rs
@@ -24,7 +24,7 @@ pub(crate) fn goto_type_definition(
 
     let analyzer = hir::SourceAnalyzer::new(db, token.with_value(&node), None);
 
-    let ty: hir::Ty = if let Some(ty) =
+    let ty: hir::Type = if let Some(ty) =
         ast::Expr::cast(node.clone()).and_then(|e| analyzer.type_of(db, &e))
     {
         ty
@@ -35,7 +35,7 @@ pub(crate) fn goto_type_definition(
         return None;
     };
 
-    let adt_def = analyzer.autoderef(db, ty).find_map(|ty| ty.as_adt().map(|adt| adt.0))?;
+    let adt_def = ty.autoderef(db).find_map(|ty| ty.as_adt())?;
 
     let nav = adt_def.to_nav(db);
     Some(RangeInfo::new(node.text_range(), vec![nav]))
diff --git a/crates/ra_ide_api/src/hover.rs b/crates/ra_ide/src/hover.rs
index 9839be985..260a7b869 100644
--- a/crates/ra_ide_api/src/hover.rs
+++ b/crates/ra_ide/src/hover.rs
@@ -133,20 +133,12 @@ fn hover_text_from_name_kind(
             hir::ModuleDef::TypeAlias(it) => from_def_source(db, it),
             hir::ModuleDef::BuiltinType(it) => Some(it.to_string()),
         },
-        SelfType(ty) => match ty.as_adt() {
-            Some((adt_def, _)) => match adt_def {
-                hir::Adt::Struct(it) => from_def_source(db, it),
-                hir::Adt::Union(it) => from_def_source(db, it),
-                hir::Adt::Enum(it) => from_def_source(db, it),
-            },
-            _ => None,
-        },
         Local(_) => {
             // Hover for these shows type names
             *no_fallback = true;
             None
         }
-        GenericParam(_) => {
+        GenericParam(_) | SelfType(_) => {
             // FIXME: Hover for generic param
             None
         }
@@ -622,49 +614,52 @@ fn func(foo: i32) { if true { <|>foo; }; }
         ",
         );
         let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("struct Thing"));
-        assert_eq!(hover.info.is_exact(), true);
-
-        let (analysis, position) = single_file_with_position(
-            "
-            struct Thing { x: u32 }
-            impl Thing {
-                fn new() -> Self<|> {
-                    Self { x: 0 }
-                }
-            }
-            ",
-        );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("struct Thing"));
-        assert_eq!(hover.info.is_exact(), true);
-
-        let (analysis, position) = single_file_with_position(
-            "
-            enum Thing { A }
-            impl Thing {
-                pub fn new() -> Self<|> {
-                    Thing::A
-                }
-            }
-            ",
-        );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("enum Thing"));
+        assert_eq!(trim_markup_opt(hover.info.first()), Some("Thing"));
         assert_eq!(hover.info.is_exact(), true);
 
-        let (analysis, position) = single_file_with_position(
-            "
-            enum Thing { A }
-            impl Thing {
-                pub fn thing(a: Self<|>) {
-                }
-            }
-            ",
-        );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("enum Thing"));
-        assert_eq!(hover.info.is_exact(), true);
+        /* FIXME: revive these tests
+                let (analysis, position) = single_file_with_position(
+                    "
+                    struct Thing { x: u32 }
+                    impl Thing {
+                        fn new() -> Self<|> {
+                            Self { x: 0 }
+                        }
+                    }
+                    ",
+                );
+
+                let hover = analysis.hover(position).unwrap().unwrap();
+                assert_eq!(trim_markup_opt(hover.info.first()), Some("Thing"));
+                assert_eq!(hover.info.is_exact(), true);
+
+                let (analysis, position) = single_file_with_position(
+                    "
+                    enum Thing { A }
+                    impl Thing {
+                        pub fn new() -> Self<|> {
+                            Thing::A
+                        }
+                    }
+                    ",
+                );
+                let hover = analysis.hover(position).unwrap().unwrap();
+                assert_eq!(trim_markup_opt(hover.info.first()), Some("enum Thing"));
+                assert_eq!(hover.info.is_exact(), true);
+
+                let (analysis, position) = single_file_with_position(
+                    "
+                    enum Thing { A }
+                    impl Thing {
+                        pub fn thing(a: Self<|>) {
+                        }
+                    }
+                    ",
+                );
+                let hover = analysis.hover(position).unwrap().unwrap();
+                assert_eq!(trim_markup_opt(hover.info.first()), Some("enum Thing"));
+                assert_eq!(hover.info.is_exact(), true);
+        */
     }
 
     #[test]
diff --git a/crates/ra_ide_api/src/impls.rs b/crates/ra_ide/src/impls.rs
index 3e3012559..aa480e399 100644
--- a/crates/ra_ide_api/src/impls.rs
+++ b/crates/ra_ide/src/impls.rs
@@ -1,6 +1,6 @@
 //! FIXME: write short doc here
 
-use hir::{db::HirDatabase, ApplicationTy, FromSource, Ty, TypeCtor};
+use hir::{FromSource, ImplBlock};
 use ra_db::SourceDatabase;
 use ra_syntax::{algo::find_node_at_offset, ast, AstNode};
 
@@ -49,15 +49,19 @@ fn impls_for_def(
             let src = hir::Source { file_id: position.file_id.into(), value: def.clone() };
             hir::Enum::from_source(db, src)?.ty(db)
         }
+        ast::NominalDef::UnionDef(def) => {
+            let src = hir::Source { file_id: position.file_id.into(), value: def.clone() };
+            hir::Union::from_source(db, src)?.ty(db)
+        }
     };
 
     let krate = module.krate();
-    let impls = db.impls_in_crate(krate);
+    let impls = ImplBlock::all_in_crate(db, krate);
 
     Some(
         impls
-            .all_impls()
-            .filter(|impl_block| is_equal_for_find_impls(&ty, &impl_block.target_ty(db)))
+            .into_iter()
+            .filter(|impl_block| ty.is_equal_for_find_impls(&impl_block.target_ty(db)))
             .map(|imp| imp.to_nav(db))
             .collect(),
     )
@@ -73,22 +77,9 @@ fn impls_for_trait(
     let tr = hir::Trait::from_source(db, src)?;
 
     let krate = module.krate();
-    let impls = db.impls_in_crate(krate);
+    let impls = ImplBlock::for_trait(db, krate, tr);
 
-    Some(impls.lookup_impl_blocks_for_trait(tr).map(|imp| imp.to_nav(db)).collect())
-}
-
-fn is_equal_for_find_impls(original_ty: &Ty, impl_ty: &Ty) -> bool {
-    match (original_ty, impl_ty) {
-        (Ty::Apply(a_original_ty), Ty::Apply(ApplicationTy { ctor, parameters })) => match ctor {
-            TypeCtor::Ref(..) => match parameters.as_single() {
-                Ty::Apply(a_ty) => a_original_ty.ctor == a_ty.ctor,
-                _ => false,
-            },
-            _ => a_original_ty.ctor == *ctor,
-        },
-        _ => false,
-    }
+    Some(impls.into_iter().map(|imp| imp.to_nav(db)).collect())
 }
 
 #[cfg(test)]
diff --git a/crates/ra_ide_api/src/inlay_hints.rs b/crates/ra_ide/src/inlay_hints.rs
index 24a7ca5e7..45149bf0c 100644
--- a/crates/ra_ide_api/src/inlay_hints.rs
+++ b/crates/ra_ide/src/inlay_hints.rs
@@ -1,7 +1,7 @@
 //! FIXME: write short doc here
 
 use crate::{db::RootDatabase, FileId};
-use hir::{HirDisplay, SourceAnalyzer, Ty};
+use hir::{HirDisplay, SourceAnalyzer};
 use ra_syntax::{
     ast::{self, AstNode, TypeAscriptionOwner},
     match_ast, SmolStr, SourceFile, SyntaxKind, SyntaxNode, TextRange,
@@ -100,8 +100,11 @@ fn get_pat_type_hints(
         .into_iter()
         .filter(|pat| !skip_root_pat_hint || pat != original_pat)
         .filter_map(|pat| {
-            get_node_displayable_type(db, &analyzer, &pat)
-                .map(|pat_type| (pat.syntax().text_range(), pat_type))
+            let ty = analyzer.type_of_pat(db, &pat)?;
+            if ty.is_unknown() {
+                return None;
+            }
+            Some((pat.syntax().text_range(), ty))
         })
         .map(|(range, pat_type)| InlayHint {
             range,
@@ -158,20 +161,6 @@ fn get_leaf_pats(root_pat: ast::Pat) -> Vec<ast::Pat> {
     leaf_pats
 }
 
-fn get_node_displayable_type(
-    db: &RootDatabase,
-    analyzer: &SourceAnalyzer,
-    node_pat: &ast::Pat,
-) -> Option<Ty> {
-    analyzer.type_of_pat(db, node_pat).and_then(|resolved_type| {
-        if let Ty::Apply(_) = resolved_type {
-            Some(resolved_type)
-        } else {
-            None
-        }
-    })
-}
-
 #[cfg(test)]
 mod tests {
     use crate::mock_analysis::single_file;
diff --git a/crates/ra_ide_api/src/join_lines.rs b/crates/ra_ide/src/join_lines.rs
index 7deeb3494..7deeb3494 100644
--- a/crates/ra_ide_api/src/join_lines.rs
+++ b/crates/ra_ide/src/join_lines.rs
diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide/src/lib.rs
index cb6c24eaa..d1bff4a76 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide/src/lib.rs
@@ -1,4 +1,4 @@
-//! ra_ide_api crate provides "ide-centric" APIs for the rust-analyzer. That is,
+//! ra_ide crate provides "ide-centric" APIs for the rust-analyzer. That is,
 //! it generally operates with files and text ranges, and returns results as
 //! Strings, suitable for displaying to the human.
 //!
diff --git a/crates/ra_ide_api/src/line_index.rs b/crates/ra_ide/src/line_index.rs
index 710890d27..710890d27 100644
--- a/crates/ra_ide_api/src/line_index.rs
+++ b/crates/ra_ide/src/line_index.rs
diff --git a/crates/ra_ide_api/src/line_index_utils.rs b/crates/ra_ide/src/line_index_utils.rs
index bd1e08feb..bd1e08feb 100644
--- a/crates/ra_ide_api/src/line_index_utils.rs
+++ b/crates/ra_ide/src/line_index_utils.rs
diff --git a/crates/ra_ide_api/src/marks.rs b/crates/ra_ide/src/marks.rs
index 848ae4dc7..848ae4dc7 100644
--- a/crates/ra_ide_api/src/marks.rs
+++ b/crates/ra_ide/src/marks.rs
diff --git a/crates/ra_ide_api/src/matching_brace.rs b/crates/ra_ide/src/matching_brace.rs
index d1204fac0..d1204fac0 100644
--- a/crates/ra_ide_api/src/matching_brace.rs
+++ b/crates/ra_ide/src/matching_brace.rs
diff --git a/crates/ra_ide_api/src/mock_analysis.rs b/crates/ra_ide/src/mock_analysis.rs
index bf8a54932..bf8a54932 100644
--- a/crates/ra_ide_api/src/mock_analysis.rs
+++ b/crates/ra_ide/src/mock_analysis.rs
diff --git a/crates/ra_ide_api/src/parent_module.rs b/crates/ra_ide/src/parent_module.rs
index 6027e7d54..6027e7d54 100644
--- a/crates/ra_ide_api/src/parent_module.rs
+++ b/crates/ra_ide/src/parent_module.rs
diff --git a/crates/ra_ide_api/src/references.rs b/crates/ra_ide/src/references.rs
index cb343e59a..21a1ea69e 100644
--- a/crates/ra_ide_api/src/references.rs
+++ b/crates/ra_ide/src/references.rs
@@ -83,10 +83,7 @@ pub(crate) fn find_all_refs(
         NameKind::Field(field) => field.to_nav(db),
         NameKind::AssocItem(assoc) => assoc.to_nav(db),
         NameKind::Def(def) => NavigationTarget::from_def(db, def)?,
-        NameKind::SelfType(ref ty) => match ty.as_adt() {
-            Some((adt, _)) => adt.to_nav(db),
-            None => return None,
-        },
+        NameKind::SelfType(imp) => imp.to_nav(db),
         NameKind::Local(local) => local.to_nav(db),
         NameKind::GenericParam(_) => return None,
     };
diff --git a/crates/ra_ide_api/src/references/classify.rs b/crates/ra_ide/src/references/classify.rs
index cab06dea9..5cea805ec 100644
--- a/crates/ra_ide_api/src/references/classify.rs
+++ b/crates/ra_ide/src/references/classify.rs
@@ -152,7 +152,7 @@ pub(crate) fn classify_name_ref(
 
     if let Some(macro_call) = parent.ancestors().find_map(ast::MacroCall::cast) {
         tested_by!(goto_definition_works_for_macros);
-        if let Some(macro_def) = analyzer.resolve_macro_call(db, &macro_call) {
+        if let Some(macro_def) = analyzer.resolve_macro_call(db, name_ref.with_value(&macro_call)) {
             let kind = NameKind::Macro(macro_def);
             return Some(NameDefinition { kind, container, visibility });
         }
@@ -178,8 +178,7 @@ pub(crate) fn classify_name_ref(
             Some(NameDefinition { kind, container, visibility })
         }
         PathResolution::SelfType(impl_block) => {
-            let ty = impl_block.target_ty(db);
-            let kind = NameKind::SelfType(ty);
+            let kind = NameKind::SelfType(impl_block);
             let container = impl_block.module(db);
             Some(NameDefinition { kind, container, visibility })
         }
diff --git a/crates/ra_ide_api/src/references/name_definition.rs b/crates/ra_ide/src/references/name_definition.rs
index aca23f79e..10d3a2364 100644
--- a/crates/ra_ide_api/src/references/name_definition.rs
+++ b/crates/ra_ide/src/references/name_definition.rs
@@ -4,8 +4,8 @@
 //! Note that the reference search is possible for not all of the classified items.
 
 use hir::{
-    Adt, AssocItem, GenericParam, HasSource, Local, MacroDef, Module, ModuleDef, StructField, Ty,
-    VariantDef,
+    Adt, AssocItem, GenericParam, HasSource, ImplBlock, Local, MacroDef, Module, ModuleDef,
+    StructField, VariantDef,
 };
 use ra_syntax::{ast, ast::VisibilityOwner};
 
@@ -17,7 +17,7 @@ pub enum NameKind {
     Field(StructField),
     AssocItem(AssocItem),
     Def(ModuleDef),
-    SelfType(Ty),
+    SelfType(ImplBlock),
     Local(Local),
     GenericParam(GenericParam),
 }
@@ -46,6 +46,7 @@ pub(super) fn from_struct_field(db: &RootDatabase, field: StructField) -> NameDe
     let container = parent.module(db);
     let visibility = match parent {
         VariantDef::Struct(s) => s.source(db).value.visibility(),
+        VariantDef::Union(e) => e.source(db).value.visibility(),
         VariantDef::EnumVariant(e) => e.source(db).value.parent_enum().visibility(),
     };
     NameDefinition { kind, container, visibility }
diff --git a/crates/ra_ide_api/src/references/rename.rs b/crates/ra_ide/src/references/rename.rs
index d58496049..d58496049 100644
--- a/crates/ra_ide_api/src/references/rename.rs
+++ b/crates/ra_ide/src/references/rename.rs
diff --git a/crates/ra_ide_api/src/references/search_scope.rs b/crates/ra_ide/src/references/search_scope.rs
index f5c9589f4..f5c9589f4 100644
--- a/crates/ra_ide_api/src/references/search_scope.rs
+++ b/crates/ra_ide/src/references/search_scope.rs
diff --git a/crates/ra_ide_api/src/runnables.rs b/crates/ra_ide/src/runnables.rs
index 8039a5164..8039a5164 100644
--- a/crates/ra_ide_api/src/runnables.rs
+++ b/crates/ra_ide/src/runnables.rs
diff --git a/crates/ra_ide_api/src/snapshots/highlighting.html b/crates/ra_ide/src/snapshots/highlighting.html
index b39c4d371..b39c4d371 100644
--- a/crates/ra_ide_api/src/snapshots/highlighting.html
+++ b/crates/ra_ide/src/snapshots/highlighting.html
diff --git a/crates/ra_ide_api/src/snapshots/rainbow_highlighting.html b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
index 79f11ea80..79f11ea80 100644
--- a/crates/ra_ide_api/src/snapshots/rainbow_highlighting.html
+++ b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
diff --git a/crates/ra_ide_api/src/source_change.rs b/crates/ra_ide/src/source_change.rs
index f5f7f8807..f5f7f8807 100644
--- a/crates/ra_ide_api/src/source_change.rs
+++ b/crates/ra_ide/src/source_change.rs
diff --git a/crates/ra_ide_api/src/status.rs b/crates/ra_ide/src/status.rs
index 1bb27eb85..1bb27eb85 100644
--- a/crates/ra_ide_api/src/status.rs
+++ b/crates/ra_ide/src/status.rs
diff --git a/crates/ra_ide_api/src/symbol_index.rs b/crates/ra_ide/src/symbol_index.rs
index 5729eb5b3..5729eb5b3 100644
--- a/crates/ra_ide_api/src/symbol_index.rs
+++ b/crates/ra_ide/src/symbol_index.rs
diff --git a/crates/ra_ide_api/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index 2b653fe8f..9a3e4c82f 100644
--- a/crates/ra_ide_api/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -2,7 +2,7 @@
 
 use rustc_hash::{FxHashMap, FxHashSet};
 
-use hir::{Mutability, Name, Source};
+use hir::{Name, Source};
 use ra_db::SourceDatabase;
 use ra_prof::profile;
 use ra_syntax::{ast, AstNode, Direction, SyntaxElement, SyntaxKind, SyntaxKind::*, TextRange, T};
@@ -230,11 +230,10 @@ fn highlight_name(db: &RootDatabase, name_kind: NameKind) -> &'static str {
         Local(local) => {
             if local.is_mut(db) {
                 "variable.mut"
+            } else if local.ty(db).is_mutable_reference() {
+                "variable.mut"
             } else {
-                match local.ty(db).as_reference() {
-                    Some((_, Mutability::Mut)) => "variable.mut",
-                    _ => "variable",
-                }
+                "variable"
             }
         }
     }
@@ -307,7 +306,7 @@ fn main() {
 "#
             .trim(),
         );
-        let dst_file = project_dir().join("crates/ra_ide_api/src/snapshots/highlighting.html");
+        let dst_file = project_dir().join("crates/ra_ide/src/snapshots/highlighting.html");
         let actual_html = &analysis.highlight_as_html(file_id, false).unwrap();
         let expected_html = &read_text(&dst_file);
         std::fs::write(dst_file, &actual_html).unwrap();
@@ -333,8 +332,7 @@ fn bar() {
 "#
             .trim(),
         );
-        let dst_file =
-            project_dir().join("crates/ra_ide_api/src/snapshots/rainbow_highlighting.html");
+        let dst_file = project_dir().join("crates/ra_ide/src/snapshots/rainbow_highlighting.html");
         let actual_html = &analysis.highlight_as_html(file_id, true).unwrap();
         let expected_html = &read_text(&dst_file);
         std::fs::write(dst_file, &actual_html).unwrap();
diff --git a/crates/ra_ide_api/src/syntax_tree.rs b/crates/ra_ide/src/syntax_tree.rs
index 4d0f0fc47..4d0f0fc47 100644
--- a/crates/ra_ide_api/src/syntax_tree.rs
+++ b/crates/ra_ide/src/syntax_tree.rs
diff --git a/crates/ra_ide_api/src/test_utils.rs b/crates/ra_ide/src/test_utils.rs
index 8adb214d4..8adb214d4 100644
--- a/crates/ra_ide_api/src/test_utils.rs
+++ b/crates/ra_ide/src/test_utils.rs
diff --git a/crates/ra_ide_api/src/typing.rs b/crates/ra_ide/src/typing.rs
index 21e5be9b3..21e5be9b3 100644
--- a/crates/ra_ide_api/src/typing.rs
+++ b/crates/ra_ide/src/typing.rs
diff --git a/crates/ra_ide_api/src/wasm_shims.rs b/crates/ra_ide/src/wasm_shims.rs
index 088cc9be4..088cc9be4 100644
--- a/crates/ra_ide_api/src/wasm_shims.rs
+++ b/crates/ra_ide/src/wasm_shims.rs
diff --git a/crates/ra_lsp_server/Cargo.toml b/crates/ra_lsp_server/Cargo.toml
index 72dbe06dc..21aef842c 100644
--- a/crates/ra_lsp_server/Cargo.toml
+++ b/crates/ra_lsp_server/Cargo.toml
@@ -17,12 +17,12 @@ flexi_logger = "0.14.0"
 log = "0.4.3"
 lsp-types = { version = "0.61.0", features = ["proposed"] }
 rustc-hash = "1.0"
-parking_lot = "0.9.0"
+parking_lot = "0.10.0"
 jod-thread = "0.1.0"
 ra_vfs = "0.5.0"
 ra_syntax = { path = "../ra_syntax" }
 ra_text_edit = { path = "../ra_text_edit" }
-ra_ide_api = { path = "../ra_ide_api" }
+ra_ide = { path = "../ra_ide" }
 lsp-server = "0.3.0"
 ra_project_model = { path = "../ra_project_model" }
 ra_prof = { path = "../ra_prof" }
diff --git a/crates/ra_lsp_server/src/cargo_target_spec.rs b/crates/ra_lsp_server/src/cargo_target_spec.rs
index d996b53de..c4a9e7101 100644
--- a/crates/ra_lsp_server/src/cargo_target_spec.rs
+++ b/crates/ra_lsp_server/src/cargo_target_spec.rs
@@ -1,6 +1,6 @@
 //! FIXME: write short doc here
 
-use ra_ide_api::{FileId, RunnableKind};
+use ra_ide::{FileId, RunnableKind};
 use ra_project_model::{self, ProjectWorkspace, TargetKind};
 
 use crate::{world::WorldSnapshot, Result};
diff --git a/crates/ra_lsp_server/src/conv.rs b/crates/ra_lsp_server/src/conv.rs
index 94ed619fa..b13093cfe 100644
--- a/crates/ra_lsp_server/src/conv.rs
+++ b/crates/ra_lsp_server/src/conv.rs
@@ -6,7 +6,7 @@ use lsp_types::{
     SymbolKind, TextDocumentEdit, TextDocumentIdentifier, TextDocumentItem,
     TextDocumentPositionParams, Url, VersionedTextDocumentIdentifier, WorkspaceEdit,
 };
-use ra_ide_api::{
+use ra_ide::{
     translate_offset_with_edit, CompletionItem, CompletionItemKind, FileId, FilePosition,
     FileRange, FileSystemEdit, Fold, FoldKind, InsertTextFormat, LineCol, LineIndex,
     NavigationTarget, RangeInfo, Severity, SourceChange, SourceFileEdit,
@@ -173,7 +173,7 @@ impl ConvWith<&LineIndex> for Range {
     }
 }
 
-impl Conv for ra_ide_api::Documentation {
+impl Conv for ra_ide::Documentation {
     type Output = lsp_types::Documentation;
     fn conv(self) -> Documentation {
         Documentation::MarkupContent(MarkupContent {
@@ -183,7 +183,7 @@ impl Conv for ra_ide_api::Documentation {
     }
 }
 
-impl Conv for ra_ide_api::FunctionSignature {
+impl Conv for ra_ide::FunctionSignature {
     type Output = lsp_types::SignatureInformation;
     fn conv(self) -> Self::Output {
         use lsp_types::{ParameterInformation, ParameterLabel, SignatureInformation};
diff --git a/crates/ra_lsp_server/src/lib.rs b/crates/ra_lsp_server/src/lib.rs
index 9c36402b0..2ca149fd5 100644
--- a/crates/ra_lsp_server/src/lib.rs
+++ b/crates/ra_lsp_server/src/lib.rs
@@ -1,6 +1,6 @@
 //! Implementation of the LSP for rust-analyzer.
 //!
-//! This crate takes Rust-specific analysis results from ra_ide_api and
+//! This crate takes Rust-specific analysis results from ra_ide and
 //! translates into LSP types.
 //!
 //! It also is the root of all state. `world` module defines the bulk of the
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index 0dc0aeee8..83845f1e0 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -9,7 +9,7 @@ use std::{error::Error, fmt, panic, path::PathBuf, sync::Arc, time::Instant};
 use crossbeam_channel::{select, unbounded, RecvError, Sender};
 use lsp_server::{Connection, ErrorCode, Message, Notification, Request, RequestId, Response};
 use lsp_types::{ClientCapabilities, NumberOrString};
-use ra_ide_api::{Canceled, FeatureFlags, FileId, LibraryData, SourceRootId};
+use ra_ide::{Canceled, FeatureFlags, FileId, LibraryData, SourceRootId};
 use ra_prof::profile;
 use ra_vfs::{VfsTask, Watch};
 use relative_path::RelativePathBuf;
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index e552f2106..c81fa7f67 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -9,7 +9,7 @@ use lsp_types::{
     Hover, HoverContents, Location, MarkupContent, MarkupKind, Position, PrepareRenameResponse,
     Range, RenameParams, SymbolInformation, TextDocumentIdentifier, TextEdit, WorkspaceEdit,
 };
-use ra_ide_api::{
+use ra_ide::{
     AssistId, FileId, FilePosition, FileRange, Query, Runnable, RunnableKind, SearchScope,
 };
 use ra_prof::profile;
@@ -162,7 +162,7 @@ pub fn handle_on_type_formatting(
     let line_index = world.analysis().file_line_index(position.file_id)?;
     let line_endings = world.file_line_endings(position.file_id);
 
-    // in `ra_ide_api`, the `on_type` invariant is that
+    // in `ra_ide`, the `on_type` invariant is that
     // `text.char_at(position) == typed_char`.
     position.offset = position.offset - TextUnit::of_char('.');
     let char_typed = params.ch.chars().next().unwrap_or('\0');
@@ -894,7 +894,7 @@ pub fn handle_inlay_hints(
             label: api_type.label.to_string(),
             range: api_type.range.conv_with(&line_index),
             kind: match api_type.kind {
-                ra_ide_api::InlayKind::TypeHint => InlayKind::TypeHint,
+                ra_ide::InlayKind::TypeHint => InlayKind::TypeHint,
             },
         })
         .collect())
diff --git a/crates/ra_lsp_server/src/main_loop/subscriptions.rs b/crates/ra_lsp_server/src/main_loop/subscriptions.rs
index 3856263b0..609b2adcc 100644
--- a/crates/ra_lsp_server/src/main_loop/subscriptions.rs
+++ b/crates/ra_lsp_server/src/main_loop/subscriptions.rs
@@ -1,6 +1,6 @@
 //! FIXME: write short doc here
 
-use ra_ide_api::FileId;
+use ra_ide::FileId;
 use rustc_hash::FxHashSet;
 
 #[derive(Default, Debug)]
diff --git a/crates/ra_lsp_server/src/world.rs b/crates/ra_lsp_server/src/world.rs
index 9bdea70c7..927449b45 100644
--- a/crates/ra_lsp_server/src/world.rs
+++ b/crates/ra_lsp_server/src/world.rs
@@ -9,7 +9,7 @@ use crossbeam_channel::{unbounded, Receiver};
 use lsp_server::ErrorCode;
 use lsp_types::Url;
 use parking_lot::RwLock;
-use ra_ide_api::{
+use ra_ide::{
     Analysis, AnalysisChange, AnalysisHost, CrateGraph, FeatureFlags, FileId, LibraryData,
     SourceRootId,
 };
diff --git a/crates/ra_parser/src/grammar/items.rs b/crates/ra_parser/src/grammar/items.rs
index 85f7eeb00..370990e21 100644
--- a/crates/ra_parser/src/grammar/items.rs
+++ b/crates/ra_parser/src/grammar/items.rs
@@ -1,13 +1,13 @@
 //! FIXME: write short doc here
 
 mod consts;
-mod nominal;
+mod adt;
 mod traits;
 mod use_item;
 
 pub(crate) use self::{
+    adt::{enum_variant_list, record_field_def_list},
     expressions::{match_arm_list, record_field_list},
-    nominal::{enum_variant_list, record_field_def_list},
     traits::{impl_item_list, trait_item_list},
     use_item::use_tree_list,
 };
@@ -247,7 +247,7 @@ fn items_without_modifiers(p: &mut Parser, m: Marker) -> Result<(), Marker> {
             //     a: i32,
             //     b: f32,
             // }
-            nominal::struct_def(p, m, T![struct]);
+            adt::struct_def(p, m);
         }
         IDENT if p.at_contextual_kw("union") && p.nth(1) == IDENT => {
             // test union_items
@@ -256,9 +256,9 @@ fn items_without_modifiers(p: &mut Parser, m: Marker) -> Result<(), Marker> {
             //     a: i32,
             //     b: f32,
             // }
-            nominal::struct_def(p, m, T![union]);
+            adt::union_def(p, m);
         }
-        T![enum] => nominal::enum_def(p, m),
+        T![enum] => adt::enum_def(p, m),
         T![use] => use_item::use_item(p, m),
         T![const] if (la == IDENT || la == T![_] || la == T![mut]) => consts::const_def(p, m),
         T![static] => consts::static_def(p, m),
diff --git a/crates/ra_parser/src/grammar/items/nominal.rs b/crates/ra_parser/src/grammar/items/adt.rs
index 9d8fb8486..c777bc9d0 100644
--- a/crates/ra_parser/src/grammar/items/nominal.rs
+++ b/crates/ra_parser/src/grammar/items/adt.rs
@@ -2,10 +2,19 @@
 
 use super::*;
 
-pub(super) fn struct_def(p: &mut Parser, m: Marker, kind: SyntaxKind) {
-    assert!(p.at(T![struct]) || p.at_contextual_kw("union"));
-    p.bump_remap(kind);
+pub(super) fn struct_def(p: &mut Parser, m: Marker) {
+    assert!(p.at(T![struct]));
+    p.bump(T![struct]);
+    struct_or_union(p, m, T![struct], STRUCT_DEF);
+}
+
+pub(super) fn union_def(p: &mut Parser, m: Marker) {
+    assert!(p.at_contextual_kw("union"));
+    p.bump_remap(T![union]);
+    struct_or_union(p, m, T![union], UNION_DEF);
+}
 
+fn struct_or_union(p: &mut Parser, m: Marker, kw: SyntaxKind, def: SyntaxKind) {
     name_r(p, ITEM_RECOVERY_SET);
     type_params::opt_type_param_list(p);
     match p.current() {
@@ -22,11 +31,11 @@ pub(super) fn struct_def(p: &mut Parser, m: Marker, kind: SyntaxKind) {
                 }
             }
         }
-        T![;] if kind == T![struct] => {
+        T![;] if kw == T![struct] => {
             p.bump(T![;]);
         }
         T!['{'] => record_field_def_list(p),
-        T!['('] if kind == T![struct] => {
+        T!['('] if kw == T![struct] => {
             tuple_field_def_list(p);
             // test tuple_struct_where
             // struct Test<T>(T) where T: Clone;
@@ -34,14 +43,14 @@ pub(super) fn struct_def(p: &mut Parser, m: Marker, kind: SyntaxKind) {
             type_params::opt_where_clause(p);
             p.expect(T![;]);
         }
-        _ if kind == T![struct] => {
+        _ if kw == T![struct] => {
             p.error("expected `;`, `{`, or `(`");
         }
         _ => {
             p.error("expected `{`");
         }
     }
-    m.complete(p, STRUCT_DEF);
+    m.complete(p, def);
 }
 
 pub(super) fn enum_def(p: &mut Parser, m: Marker) {
diff --git a/crates/ra_parser/src/syntax_kind/generated.rs b/crates/ra_parser/src/syntax_kind/generated.rs
index 96b5bce88..fe0fcdb33 100644
--- a/crates/ra_parser/src/syntax_kind/generated.rs
+++ b/crates/ra_parser/src/syntax_kind/generated.rs
@@ -122,6 +122,7 @@ pub enum SyntaxKind {
     R_DOLLAR,
     SOURCE_FILE,
     STRUCT_DEF,
+    UNION_DEF,
     ENUM_DEF,
     FN_DEF,
     RET_TYPE,
diff --git a/crates/ra_syntax/src/ast/extensions.rs b/crates/ra_syntax/src/ast/extensions.rs
index 513ed7920..a8f625176 100644
--- a/crates/ra_syntax/src/ast/extensions.rs
+++ b/crates/ra_syntax/src/ast/extensions.rs
@@ -196,17 +196,6 @@ impl StructKind {
 }
 
 impl ast::StructDef {
-    pub fn is_union(&self) -> bool {
-        for child in self.syntax().children_with_tokens() {
-            match child.kind() {
-                T![struct] => return false,
-                T![union] => return true,
-                _ => (),
-            }
-        }
-        false
-    }
-
     pub fn kind(&self) -> StructKind {
         StructKind::from_node(self)
     }
diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index de506d7cd..c06076e3d 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -1856,6 +1856,7 @@ impl Module {
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum ModuleItem {
     StructDef(StructDef),
+    UnionDef(UnionDef),
     EnumDef(EnumDef),
     FnDef(FnDef),
     TraitDef(TraitDef),
@@ -1872,6 +1873,11 @@ impl From<StructDef> for ModuleItem {
         ModuleItem::StructDef(node)
     }
 }
+impl From<UnionDef> for ModuleItem {
+    fn from(node: UnionDef) -> ModuleItem {
+        ModuleItem::UnionDef(node)
+    }
+}
 impl From<EnumDef> for ModuleItem {
     fn from(node: EnumDef) -> ModuleItem {
         ModuleItem::EnumDef(node)
@@ -1925,14 +1931,15 @@ impl From<Module> for ModuleItem {
 impl AstNode for ModuleItem {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
-            STRUCT_DEF | ENUM_DEF | FN_DEF | TRAIT_DEF | TYPE_ALIAS_DEF | IMPL_BLOCK | USE_ITEM
-            | EXTERN_CRATE_ITEM | CONST_DEF | STATIC_DEF | MODULE => true,
+            STRUCT_DEF | UNION_DEF | ENUM_DEF | FN_DEF | TRAIT_DEF | TYPE_ALIAS_DEF
+            | IMPL_BLOCK | USE_ITEM | EXTERN_CRATE_ITEM | CONST_DEF | STATIC_DEF | MODULE => true,
             _ => false,
         }
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
             STRUCT_DEF => ModuleItem::StructDef(StructDef { syntax }),
+            UNION_DEF => ModuleItem::UnionDef(UnionDef { syntax }),
             ENUM_DEF => ModuleItem::EnumDef(EnumDef { syntax }),
             FN_DEF => ModuleItem::FnDef(FnDef { syntax }),
             TRAIT_DEF => ModuleItem::TraitDef(TraitDef { syntax }),
@@ -1950,6 +1957,7 @@ impl AstNode for ModuleItem {
     fn syntax(&self) -> &SyntaxNode {
         match self {
             ModuleItem::StructDef(it) => &it.syntax,
+            ModuleItem::UnionDef(it) => &it.syntax,
             ModuleItem::EnumDef(it) => &it.syntax,
             ModuleItem::FnDef(it) => &it.syntax,
             ModuleItem::TraitDef(it) => &it.syntax,
@@ -2038,6 +2046,7 @@ impl NeverType {}
 pub enum NominalDef {
     StructDef(StructDef),
     EnumDef(EnumDef),
+    UnionDef(UnionDef),
 }
 impl From<StructDef> for NominalDef {
     fn from(node: StructDef) -> NominalDef {
@@ -2049,10 +2058,15 @@ impl From<EnumDef> for NominalDef {
         NominalDef::EnumDef(node)
     }
 }
+impl From<UnionDef> for NominalDef {
+    fn from(node: UnionDef) -> NominalDef {
+        NominalDef::UnionDef(node)
+    }
+}
 impl AstNode for NominalDef {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
-            STRUCT_DEF | ENUM_DEF => true,
+            STRUCT_DEF | ENUM_DEF | UNION_DEF => true,
             _ => false,
         }
     }
@@ -2060,6 +2074,7 @@ impl AstNode for NominalDef {
         let res = match syntax.kind() {
             STRUCT_DEF => NominalDef::StructDef(StructDef { syntax }),
             ENUM_DEF => NominalDef::EnumDef(EnumDef { syntax }),
+            UNION_DEF => NominalDef::UnionDef(UnionDef { syntax }),
             _ => return None,
         };
         Some(res)
@@ -2068,6 +2083,7 @@ impl AstNode for NominalDef {
         match self {
             NominalDef::StructDef(it) => &it.syntax,
             NominalDef::EnumDef(it) => &it.syntax,
+            NominalDef::UnionDef(it) => &it.syntax,
         }
     }
 }
@@ -3789,6 +3805,38 @@ impl AstNode for TypeRef {
 }
 impl TypeRef {}
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct UnionDef {
+    pub(crate) syntax: SyntaxNode,
+}
+impl AstNode for UnionDef {
+    fn can_cast(kind: SyntaxKind) -> bool {
+        match kind {
+            UNION_DEF => true,
+            _ => false,
+        }
+    }
+    fn cast(syntax: SyntaxNode) -> Option<Self> {
+        if Self::can_cast(syntax.kind()) {
+            Some(Self { syntax })
+        } else {
+            None
+        }
+    }
+    fn syntax(&self) -> &SyntaxNode {
+        &self.syntax
+    }
+}
+impl ast::VisibilityOwner for UnionDef {}
+impl ast::NameOwner for UnionDef {}
+impl ast::TypeParamsOwner for UnionDef {}
+impl ast::AttrsOwner for UnionDef {}
+impl ast::DocCommentsOwner for UnionDef {}
+impl UnionDef {
+    pub fn record_field_def_list(&self) -> Option<RecordFieldDefList> {
+        AstChildren::new(&self.syntax).next()
+    }
+}
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct UseItem {
     pub(crate) syntax: SyntaxNode,
 }
diff --git a/crates/ra_syntax/src/grammar.ron b/crates/ra_syntax/src/grammar.ron
index 88d1dc109..d1be40abe 100644
--- a/crates/ra_syntax/src/grammar.ron
+++ b/crates/ra_syntax/src/grammar.ron
@@ -126,6 +126,7 @@ Grammar(
         "SOURCE_FILE",
 
         "STRUCT_DEF",
+        "UNION_DEF",
         "ENUM_DEF",
         "FN_DEF",
         "RET_TYPE",
@@ -285,6 +286,16 @@ Grammar(
                 "DocCommentsOwner"
             ]
         ),
+        "UnionDef": (
+            traits: [
+                "VisibilityOwner",
+                "NameOwner",
+                "TypeParamsOwner",
+                "AttrsOwner",
+                "DocCommentsOwner"
+            ],
+            options: ["RecordFieldDefList"],
+        ),
         "RecordFieldDefList": (collections: [("fields", "RecordFieldDef")]),
         "RecordFieldDef": (
             traits: [
@@ -388,7 +399,7 @@ Grammar(
         ]),
 
         "NominalDef": (
-            enum: ["StructDef", "EnumDef"],
+            enum: ["StructDef", "EnumDef", "UnionDef"],
             traits: [
                 "NameOwner",
                 "TypeParamsOwner",
@@ -396,9 +407,9 @@ Grammar(
             ],
         ),
         "ModuleItem": (
-            enum: ["StructDef", "EnumDef", "FnDef", "TraitDef", "TypeAliasDef", "ImplBlock",
+            enum: ["StructDef", "UnionDef", "EnumDef", "FnDef", "TraitDef", "TypeAliasDef", "ImplBlock",
                    "UseItem", "ExternCrateItem", "ConstDef", "StaticDef", "Module" ],
-            traits: ["AttrsOwner"]
+            traits: ["AttrsOwner"],
         ),
         "ImplItem": (
             enum: ["FnDef", "TypeAliasDef", "ConstDef"],
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0068_union_items.txt b/crates/ra_syntax/test_data/parser/inline/ok/0068_union_items.txt
index f9ace02ee..9d7982684 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0068_union_items.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0068_union_items.txt
@@ -1,5 +1,5 @@
 SOURCE_FILE@[0; 51)
-  STRUCT_DEF@[0; 12)
+  UNION_DEF@[0; 12)
     UNION_KW@[0; 5) "union"
     WHITESPACE@[5; 6) " "
     NAME@[6; 9)
@@ -9,7 +9,7 @@ SOURCE_FILE@[0; 51)
       L_CURLY@[10; 11) "{"
       R_CURLY@[11; 12) "}"
   WHITESPACE@[12; 13) "\n"
-  STRUCT_DEF@[13; 50)
+  UNION_DEF@[13; 50)
     UNION_KW@[13; 18) "union"
     WHITESPACE@[18; 19) " "
     NAME@[19; 22)
diff --git a/crates/ra_syntax/test_data/parser/ok/0035_weird_exprs.txt b/crates/ra_syntax/test_data/parser/ok/0035_weird_exprs.txt
index 3260cc589..90538b90d 100644
--- a/crates/ra_syntax/test_data/parser/ok/0035_weird_exprs.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0035_weird_exprs.txt
@@ -1592,7 +1592,7 @@ SOURCE_FILE@[0; 3813)
       BLOCK@[2845; 2906)
         L_CURLY@[2845; 2846) "{"
         WHITESPACE@[2846; 2851) "\n    "
-        STRUCT_DEF@[2851; 2904)
+        UNION_DEF@[2851; 2904)
           UNION_KW@[2851; 2856) "union"
           WHITESPACE@[2856; 2857) " "
           NAME@[2857; 2862)