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());