85 files changed, 1656 insertions, 734 deletions

diff --git a/crates/ra_db/Cargo.toml b/crates/ra_db/Cargo.toml
index 2d39b77ed..3bae22c74 100644
--- a/crates/ra_db/Cargo.toml
+++ b/crates/ra_db/Cargo.toml
@@ -5,8 +5,8 @@ version = "0.1.0"
 authors = ["Aleksey Kladov <[email protected]>"]
 
 [dependencies]
+salsa = "0.10.0"
 relative-path = "0.4.0"
-salsa = "0.10.0-alpha5"
 rustc-hash = "1.0"
 parking_lot = "0.7.0"
 
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index 6e17f33f0..ca775030d 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -2,7 +2,6 @@
 mod cancellation;
 mod input;
 mod loc2id;
-pub mod mock;
 
 use std::{
     panic, sync::Arc,
diff --git a/crates/ra_db/src/mock.rs b/crates/ra_db/src/mock.rs
deleted file mode 100644
index 5e185062b..000000000
--- a/crates/ra_db/src/mock.rs
+++ /dev/null
@@ -1,30 +0,0 @@
-use rustc_hash::FxHashSet;
-use relative_path::{RelativePath, RelativePathBuf};
-
-use crate::{FileId};
-
-#[derive(Default, Debug, Clone)]
-pub struct FileMap(Vec<(FileId, RelativePathBuf)>);
-
-impl FileMap {
-    pub fn add(&mut self, path: RelativePathBuf) -> FileId {
-        let file_id = FileId((self.0.len() + 1) as u32);
-        self.0.push((file_id, path));
-        file_id
-    }
-
-    pub fn files(&self) -> FxHashSet<FileId> {
-        self.iter().map(|(id, _)| id).collect()
-    }
-
-    pub fn file_id(&self, path: &str) -> FileId {
-        assert!(path.starts_with('/'));
-        self.iter().find(|(_, p)| p == &path[1..]).unwrap().0
-    }
-
-    fn iter<'a>(&'a self) -> impl Iterator<Item = (FileId, &'a RelativePath)> + 'a {
-        self.0
-            .iter()
-            .map(|(id, path)| (*id, path.as_relative_path()))
-    }
-}
diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index 191104890..9405aa8ad 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -10,12 +10,13 @@ use crate::{
     nameres::{ModuleScope, lower::ImportId},
     db::HirDatabase,
     expr::BodySyntaxMapping,
-    ty::InferenceResult,
+    ty::{InferenceResult},
     adt::{EnumVariantId, StructFieldId, VariantDef},
     generics::GenericParams,
     docs::{Documentation, Docs, docs_from_ast},
     module_tree::ModuleId,
     ids::{FunctionId, StructId, EnumId, AstItemDef, ConstId, StaticId, TraitId, TypeId},
+    impl_block::ImplId,
 };
 
 /// hir::Crate describes a single crate. It's the main interface with which
@@ -51,7 +52,7 @@ pub enum Def {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Module {
-    pub(crate) krate: CrateId,
+    pub(crate) krate: Crate,
     pub(crate) module_id: ModuleId,
 }
 
@@ -126,9 +127,14 @@ impl Module {
         self.import_source_impl(db, import)
     }
 
+    /// Returns the syntax of the impl block in this module
+    pub fn impl_source(&self, db: &impl HirDatabase, impl_id: ImplId) -> TreeArc<ast::ImplBlock> {
+        self.impl_source_impl(db, impl_id)
+    }
+
     /// Returns the crate this module is part of.
-    pub fn krate(&self, db: &impl HirDatabase) -> Option<Crate> {
-        self.krate_impl(db)
+    pub fn krate(&self, _db: &impl HirDatabase) -> Option<Crate> {
+        Some(self.krate)
     }
 
     /// Topmost parent of this module. Every module has a `crate_root`, but some
@@ -272,6 +278,10 @@ impl Struct {
     pub fn generic_params(&self, db: &impl HirDatabase) -> Arc<GenericParams> {
         db.generic_params((*self).into())
     }
+
+    pub fn ty(&self, db: &impl HirDatabase) -> Ty {
+        db.type_for_def((*self).into())
+    }
 }
 
 impl Docs for Struct {
@@ -317,6 +327,10 @@ impl Enum {
     pub fn generic_params(&self, db: &impl HirDatabase) -> Arc<GenericParams> {
         db.generic_params((*self).into())
     }
+
+    pub fn ty(&self, db: &impl HirDatabase) -> Ty {
+        db.type_for_def((*self).into())
+    }
 }
 
 impl Docs for Enum {
@@ -382,7 +396,7 @@ pub struct Function {
     pub(crate) id: FunctionId,
 }
 
-pub use crate::code_model_impl::function::ScopeEntryWithSyntax;
+pub use crate::expr::ScopeEntryWithSyntax;
 
 /// The declared signature of a function.
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -424,12 +438,16 @@ impl Function {
         self.id.module(db)
     }
 
+    pub fn name(&self, db: &impl HirDatabase) -> Name {
+        self.signature(db).name.clone()
+    }
+
     pub fn body_syntax_mapping(&self, db: &impl HirDatabase) -> Arc<BodySyntaxMapping> {
         db.body_syntax_mapping(*self)
     }
 
     pub fn scopes(&self, db: &impl HirDatabase) -> ScopesWithSyntaxMapping {
-        let scopes = db.fn_scopes(*self);
+        let scopes = db.expr_scopes(*self);
         let syntax_mapping = db.body_syntax_mapping(*self);
         ScopesWithSyntaxMapping {
             scopes,
diff --git a/crates/ra_hir/src/code_model_impl/function.rs b/crates/ra_hir/src/code_model_impl/function.rs
index e0dd4d629..422643996 100644
--- a/crates/ra_hir/src/code_model_impl/function.rs
+++ b/crates/ra_hir/src/code_model_impl/function.rs
@@ -1,5 +1,3 @@
-mod scope;
-
 use std::sync::Arc;
 
 use ra_syntax::ast::{self, NameOwner};
@@ -11,8 +9,6 @@ use crate::{
     impl_block::ImplBlock,
 };
 
-pub use self::scope::{FnScopes, ScopesWithSyntaxMapping, ScopeEntryWithSyntax};
-
 impl Function {
     pub(crate) fn body(&self, db: &impl HirDatabase) -> Arc<Body> {
         db.body_hir(*self)
diff --git a/crates/ra_hir/src/code_model_impl/krate.rs b/crates/ra_hir/src/code_model_impl/krate.rs
index cdd30b402..86f29d959 100644
--- a/crates/ra_hir/src/code_model_impl/krate.rs
+++ b/crates/ra_hir/src/code_model_impl/krate.rs
@@ -1,31 +1,28 @@
-use ra_db::CrateId;
-
 use crate::{
     Crate, CrateDependency, AsName, Module,
     db::HirDatabase,
 };
 
 impl Crate {
-    pub(crate) fn new(crate_id: CrateId) -> Crate {
-        Crate { crate_id }
-    }
     pub(crate) fn dependencies_impl(&self, db: &impl HirDatabase) -> Vec<CrateDependency> {
         let crate_graph = db.crate_graph();
         crate_graph
             .dependencies(self.crate_id)
             .map(|dep| {
-                let krate = Crate::new(dep.crate_id());
+                let krate = Crate {
+                    crate_id: dep.crate_id(),
+                };
                 let name = dep.as_name();
                 CrateDependency { krate, name }
             })
             .collect()
     }
     pub(crate) fn root_module_impl(&self, db: &impl HirDatabase) -> Option<Module> {
-        let module_tree = db.module_tree(self.crate_id);
+        let module_tree = db.module_tree(*self);
         let module_id = module_tree.modules().next()?;
 
         let module = Module {
-            krate: self.crate_id,
+            krate: *self,
             module_id,
         };
         Some(module)
diff --git a/crates/ra_hir/src/code_model_impl/module.rs b/crates/ra_hir/src/code_model_impl/module.rs
index 418d59c91..4a3901b8b 100644
--- a/crates/ra_hir/src/code_model_impl/module.rs
+++ b/crates/ra_hir/src/code_model_impl/module.rs
@@ -3,8 +3,9 @@ use ra_syntax::{ast, SyntaxNode, TreeArc};
 
 use crate::{
     Module, ModuleSource, Problem,
-    Crate, Name,
+    Name,
     module_tree::ModuleId,
+    impl_block::ImplId,
     nameres::{lower::ImportId},
     db::HirDatabase,
 };
@@ -51,13 +52,19 @@ impl Module {
         db: &impl HirDatabase,
         import: ImportId,
     ) -> TreeArc<ast::PathSegment> {
-        let source_map = db.lower_module_source_map(self.clone());
+        let source_map = db.lower_module_source_map(*self);
         let (_, source) = self.definition_source(db);
         source_map.get(&source, import)
     }
 
-    pub(crate) fn krate_impl(&self, _db: &impl HirDatabase) -> Option<Crate> {
-        Some(Crate::new(self.krate))
+    pub(crate) fn impl_source_impl(
+        &self,
+        db: &impl HirDatabase,
+        impl_id: ImplId,
+    ) -> TreeArc<ast::ImplBlock> {
+        let source_map = db.impls_in_module_source_map(*self);
+        let (_, source) = self.definition_source(db);
+        source_map.get(&source, impl_id)
     }
 
     pub(crate) fn crate_root_impl(&self, db: &impl HirDatabase) -> Module {
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index 3f76b769d..189649841 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -1,20 +1,20 @@
 use std::sync::Arc;
 
 use ra_syntax::{SyntaxNode, TreeArc, SourceFile};
-use ra_db::{SourceDatabase, CrateId, salsa};
+use ra_db::{SourceDatabase, salsa};
 
 use crate::{
     MacroCallId, HirFileId,
     SourceFileItems, SourceItemId, Crate, Module, HirInterner,
     query_definitions,
-    Function, FnSignature, FnScopes,
+    Function, FnSignature, ExprScopes,
     Struct, Enum, StructField,
     macros::MacroExpansion,
     module_tree::ModuleTree,
     nameres::{ItemMap, lower::{LoweredModule, ImportSourceMap}},
     ty::{InferenceResult, Ty, method_resolution::CrateImplBlocks, TypableDef},
     adt::{StructData, EnumData},
-    impl_block::ModuleImplBlocks,
+    impl_block::{ModuleImplBlocks, ImplSourceMap},
     generics::{GenericParams, GenericDef},
     ids::SourceFileItemId,
 };
@@ -27,8 +27,8 @@ pub trait HirDatabase: SourceDatabase + AsRef<HirInterner> {
     #[salsa::invoke(crate::macros::expand_macro_invocation)]
     fn expand_macro_invocation(&self, invoc: MacroCallId) -> Option<Arc<MacroExpansion>>;
 
-    #[salsa::invoke(query_definitions::fn_scopes)]
-    fn fn_scopes(&self, func: Function) -> Arc<FnScopes>;
+    #[salsa::invoke(ExprScopes::expr_scopes_query)]
+    fn expr_scopes(&self, func: Function) -> Arc<ExprScopes>;
 
     #[salsa::invoke(crate::adt::StructData::struct_data_query)]
     fn struct_data(&self, s: Struct) -> Arc<StructData>;
@@ -67,15 +67,24 @@ pub trait HirDatabase: SourceDatabase + AsRef<HirInterner> {
     #[salsa::invoke(crate::nameres::lower::LoweredModule::lower_module_source_map_query)]
     fn lower_module_source_map(&self, module: Module) -> Arc<ImportSourceMap>;
 
-    #[salsa::invoke(query_definitions::item_map)]
-    fn item_map(&self, crate_id: CrateId) -> Arc<ItemMap>;
+    #[salsa::invoke(crate::nameres::ItemMap::item_map_query)]
+    fn item_map(&self, krate: Crate) -> Arc<ItemMap>;
 
     #[salsa::invoke(crate::module_tree::ModuleTree::module_tree_query)]
-    fn module_tree(&self, crate_id: CrateId) -> Arc<ModuleTree>;
+    fn module_tree(&self, krate: Crate) -> Arc<ModuleTree>;
+
+    #[salsa::invoke(crate::impl_block::impls_in_module_with_source_map_query)]
+    fn impls_in_module_with_source_map(
+        &self,
+        module: Module,
+    ) -> (Arc<ModuleImplBlocks>, Arc<ImplSourceMap>);
 
     #[salsa::invoke(crate::impl_block::impls_in_module)]
     fn impls_in_module(&self, module: Module) -> Arc<ModuleImplBlocks>;
 
+    #[salsa::invoke(crate::impl_block::impls_in_module_source_map_query)]
+    fn impls_in_module_source_map(&self, module: Module) -> Arc<ImplSourceMap>;
+
     #[salsa::invoke(crate::ty::method_resolution::CrateImplBlocks::impls_in_crate_query)]
     fn impls_in_crate(&self, krate: Crate) -> Arc<CrateImplBlocks>;
 
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index 60d997bbe..37aa24677 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -16,6 +16,10 @@ use crate::{
 };
 use crate::ty::primitive::{UintTy, UncertainIntTy, UncertainFloatTy};
 
+pub use self::scope::{ExprScopes, ScopesWithSyntaxMapping, ScopeEntryWithSyntax};
+
+mod scope;
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct ExprId(RawId);
 impl_arena_id!(ExprId);
@@ -215,7 +219,7 @@ pub use ra_syntax::ast::BinOp as BinaryOp;
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct MatchArm {
     pub pats: Vec<PatId>,
-    // guard: Option<ExprId>, // TODO
+    pub guard: Option<ExprId>,
     pub expr: ExprId,
 }
 
@@ -511,10 +515,12 @@ impl ExprCollector {
                         MatchArm {
                             pats: vec![pat],
                             expr: then_branch,
+                            guard: None,
                         },
                         MatchArm {
                             pats: vec![placeholder_pat],
                             expr: else_branch,
+                            guard: None,
                         },
                     ];
                     self.alloc_expr(
@@ -613,6 +619,10 @@ impl ExprCollector {
                         .map(|arm| MatchArm {
                             pats: arm.pats().map(|p| self.collect_pat(p)).collect(),
                             expr: self.collect_expr_opt(arm.expr()),
+                            guard: arm
+                                .guard()
+                                .and_then(|guard| guard.expr())
+                                .map(|e| self.collect_expr(e)),
                         })
                         .collect()
                 } else {
diff --git a/crates/ra_hir/src/code_model_impl/function/scope.rs b/crates/ra_hir/src/expr/scope.rs
index c5d1de5eb..f8b5ba581 100644
--- a/crates/ra_hir/src/code_model_impl/function/scope.rs
+++ b/crates/ra_hir/src/expr/scope.rs
@@ -9,14 +9,18 @@ use ra_syntax::{
 };
 use ra_arena::{Arena, RawId, impl_arena_id};
 
-use crate::{Name, AsName, expr::{PatId, ExprId, Pat, Expr, Body, Statement, BodySyntaxMapping}};
+use crate::{
+    Name, AsName, Function,
+    expr::{PatId, ExprId, Pat, Expr, Body, Statement, BodySyntaxMapping},
+    db::HirDatabase,
+};
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct ScopeId(RawId);
 impl_arena_id!(ScopeId);
 
 #[derive(Debug, PartialEq, Eq)]
-pub struct FnScopes {
+pub struct ExprScopes {
     body: Arc<Body>,
     scopes: Arena<ScopeId, ScopeData>,
     scope_for: FxHashMap<ExprId, ScopeId>,
@@ -34,9 +38,16 @@ pub struct ScopeData {
     entries: Vec<ScopeEntry>,
 }
 
-impl FnScopes {
-    pub(crate) fn new(body: Arc<Body>) -> FnScopes {
-        let mut scopes = FnScopes {
+impl ExprScopes {
+    // TODO: This should take something more general than Function
+    pub(crate) fn expr_scopes_query(db: &impl HirDatabase, function: Function) -> Arc<ExprScopes> {
+        let body = db.body_hir(function);
+        let res = ExprScopes::new(body);
+        Arc::new(res)
+    }
+
+    fn new(body: Arc<Body>) -> ExprScopes {
+        let mut scopes = ExprScopes {
             body: body.clone(),
             scopes: Arena::default(),
             scope_for: FxHashMap::default(),
@@ -119,7 +130,7 @@ impl FnScopes {
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ScopesWithSyntaxMapping {
     pub syntax_mapping: Arc<BodySyntaxMapping>,
-    pub scopes: Arc<FnScopes>,
+    pub scopes: Arc<ExprScopes>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -249,7 +260,7 @@ fn compute_block_scopes(
     statements: &[Statement],
     tail: Option<ExprId>,
     body: &Body,
-    scopes: &mut FnScopes,
+    scopes: &mut ExprScopes,
     mut scope: ScopeId,
 ) {
     for stmt in statements {
@@ -275,7 +286,7 @@ fn compute_block_scopes(
     }
 }
 
-fn compute_expr_scopes(expr: ExprId, body: &Body, scopes: &mut FnScopes, scope: ScopeId) {
+fn compute_expr_scopes(expr: ExprId, body: &Body, scopes: &mut ExprScopes, scope: ScopeId) {
     scopes.set_scope(expr, scope);
     match &body[expr] {
         Expr::Block { statements, tail } => {
@@ -344,7 +355,7 @@ mod tests {
         let marker: &ast::PathExpr = find_node_at_offset(file.syntax(), off).unwrap();
         let fn_def: &ast::FnDef = find_node_at_offset(file.syntax(), off).unwrap();
         let body_hir = expr::collect_fn_body_syntax(fn_def);
-        let scopes = FnScopes::new(Arc::clone(body_hir.body()));
+        let scopes = ExprScopes::new(Arc::clone(body_hir.body()));
         let scopes = ScopesWithSyntaxMapping {
             scopes: Arc::new(scopes),
             syntax_mapping: Arc::new(body_hir),
@@ -444,7 +455,7 @@ mod tests {
         let name_ref: &ast::NameRef = find_node_at_offset(file.syntax(), off).unwrap();
 
         let body_hir = expr::collect_fn_body_syntax(fn_def);
-        let scopes = FnScopes::new(Arc::clone(body_hir.body()));
+        let scopes = ExprScopes::new(Arc::clone(body_hir.body()));
         let scopes = ScopesWithSyntaxMapping {
             scopes: Arc::new(scopes),
             syntax_mapping: Arc::new(body_hir),
diff --git a/crates/ra_hir/src/impl_block.rs b/crates/ra_hir/src/impl_block.rs
index 222e47349..5fc26324a 100644
--- a/crates/ra_hir/src/impl_block.rs
+++ b/crates/ra_hir/src/impl_block.rs
@@ -1,8 +1,10 @@
 use std::sync::Arc;
 use rustc_hash::FxHashMap;
 
-use ra_arena::{Arena, RawId, impl_arena_id};
-use ra_syntax::ast::{self, AstNode};
+use ra_arena::{Arena, RawId, impl_arena_id, map::ArenaMap};
+use ra_syntax::{
+    AstPtr, SourceFile, TreeArc,
+ast::{self, AstNode}};
 
 use crate::{
     Const, Type,
@@ -14,6 +16,26 @@ use crate::{
 
 use crate::code_model_api::{Module, ModuleSource};
 
+#[derive(Debug, Default, PartialEq, Eq)]
+pub struct ImplSourceMap {
+    map: ArenaMap<ImplId, AstPtr<ast::ImplBlock>>,
+}
+
+impl ImplSourceMap {
+    fn insert(&mut self, impl_id: ImplId, impl_block: &ast::ImplBlock) {
+        self.map.insert(impl_id, AstPtr::new(impl_block))
+    }
+
+    pub fn get(&self, source: &ModuleSource, impl_id: ImplId) -> TreeArc<ast::ImplBlock> {
+        let file = match source {
+            ModuleSource::SourceFile(file) => &*file,
+            ModuleSource::Module(m) => m.syntax().ancestors().find_map(SourceFile::cast).unwrap(),
+        };
+
+        self.map[impl_id].to_node(file).to_owned()
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ImplBlock {
     module_impl_blocks: Arc<ModuleImplBlocks>,
@@ -39,6 +61,10 @@ impl ImplBlock {
         }
     }
 
+    pub fn id(&self) -> ImplId {
+        self.impl_id
+    }
+
     fn impl_data(&self) -> &ImplData {
         &self.module_impl_blocks.impls[self.impl_id]
     }
@@ -148,7 +174,7 @@ impl ModuleImplBlocks {
         }
     }
 
-    fn collect(&mut self, db: &impl HirDatabase, module: Module) {
+    fn collect(&mut self, db: &impl HirDatabase, module: Module, source_map: &mut ImplSourceMap) {
         let (file_id, module_source) = module.definition_source(db);
         let file_id: HirFileId = file_id.into();
         let node = match &module_source {
@@ -165,12 +191,31 @@ impl ModuleImplBlocks {
             for &impl_item in &self.impls[id].items {
                 self.impls_by_def.insert(impl_item, id);
             }
+
+            source_map.insert(id, impl_block_ast);
         }
     }
 }
 
-pub(crate) fn impls_in_module(db: &impl HirDatabase, module: Module) -> Arc<ModuleImplBlocks> {
+pub(crate) fn impls_in_module_with_source_map_query(
+    db: &impl HirDatabase,
+    module: Module,
+) -> (Arc<ModuleImplBlocks>, Arc<ImplSourceMap>) {
+    let mut source_map = ImplSourceMap::default();
+
     let mut result = ModuleImplBlocks::new();
-    result.collect(db, module);
-    Arc::new(result)
+    result.collect(db, module, &mut source_map);
+
+    (Arc::new(result), Arc::new(source_map))
+}
+
+pub(crate) fn impls_in_module(db: &impl HirDatabase, module: Module) -> Arc<ModuleImplBlocks> {
+    db.impls_in_module_with_source_map(module).0
+}
+
+pub(crate) fn impls_in_module_source_map_query(
+    db: &impl HirDatabase,
+    module: Module,
+) -> Arc<ImplSourceMap> {
+    db.impls_in_module_with_source_map(module).1
 }
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index eaf8565ee..0b9ee63bf 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -57,9 +57,9 @@ pub use self::{
     nameres::{ItemMap, PerNs, Namespace, Resolution},
     ty::Ty,
     impl_block::{ImplBlock, ImplItem},
-    code_model_impl::function::{FnScopes, ScopesWithSyntaxMapping},
     docs::{Docs, Documentation},
     adt::AdtDef,
+    expr::{ExprScopes, ScopesWithSyntaxMapping},
 };
 
 pub use self::code_model_api::{
diff --git a/crates/ra_hir/src/module_tree.rs b/crates/ra_hir/src/module_tree.rs
index d1dc3fa4b..1f327eeb2 100644
--- a/crates/ra_hir/src/module_tree.rs
+++ b/crates/ra_hir/src/module_tree.rs
@@ -2,7 +2,7 @@ use std::sync::Arc;
 
 use arrayvec::ArrayVec;
 use relative_path::RelativePathBuf;
-use ra_db::{FileId, SourceRoot, CrateId};
+use ra_db::{FileId, SourceRoot};
 use ra_syntax::{
     SyntaxNode, TreeArc,
     algo::generate,
@@ -13,6 +13,7 @@ use test_utils::tested_by;
 
 use crate::{
     Name, AsName, HirDatabase, SourceItemId, HirFileId, Problem, SourceFileItems, ModuleSource,
+    Crate,
     ids::SourceFileItemId,
 };
 
@@ -132,10 +133,10 @@ struct LinkData {
 }
 
 impl ModuleTree {
-    pub(crate) fn module_tree_query(db: &impl HirDatabase, crate_id: CrateId) -> Arc<ModuleTree> {
+    pub(crate) fn module_tree_query(db: &impl HirDatabase, krate: Crate) -> Arc<ModuleTree> {
         db.check_canceled();
         let mut res = ModuleTree::default();
-        res.init_crate(db, crate_id);
+        res.init_crate(db, krate);
         Arc::new(res)
     }
 
@@ -155,9 +156,9 @@ impl ModuleTree {
         Some(res)
     }
 
-    fn init_crate(&mut self, db: &impl HirDatabase, crate_id: CrateId) {
+    fn init_crate(&mut self, db: &impl HirDatabase, krate: Crate) {
         let crate_graph = db.crate_graph();
-        let file_id = crate_graph.crate_root(crate_id);
+        let file_id = crate_graph.crate_root(krate.crate_id);
         let source_root_id = db.file_source_root(file_id);
 
         let source_root = db.source_root(source_root_id);
@@ -172,6 +173,7 @@ impl ModuleTree {
         file_id: HirFileId,
         decl_id: Option<SourceFileItemId>,
     ) -> ModuleId {
+        let is_root = parent.is_none();
         let id = self.alloc_mod(ModuleData {
             file_id,
             decl_id,
@@ -191,7 +193,7 @@ impl ModuleTree {
             });
 
             let (points_to, problem) = if sub.is_declaration {
-                let (points_to, problem) = resolve_submodule(db, file_id, &sub.name);
+                let (points_to, problem) = resolve_submodule(db, file_id, &sub.name, is_root);
                 let points_to = points_to
                     .into_iter()
                     .map(|file_id| {
@@ -295,6 +297,7 @@ fn resolve_submodule(
     db: &impl HirDatabase,
     file_id: HirFileId,
     name: &Name,
+    is_root: bool,
 ) -> (Vec<FileId>, Option<Problem>) {
     // FIXME: handle submodules of inline modules properly
     let file_id = file_id.original_file(db);
@@ -303,7 +306,7 @@ fn resolve_submodule(
     let root = RelativePathBuf::default();
     let dir_path = path.parent().unwrap_or(&root);
     let mod_name = path.file_stem().unwrap_or("unknown");
-    let is_dir_owner = mod_name == "mod" || mod_name == "lib" || mod_name == "main";
+    let is_dir_owner = is_root || mod_name == "mod";
 
     let file_mod = dir_path.join(format!("{}.rs", name));
     let dir_mod = dir_path.join(format!("{}/mod.rs", name));
diff --git a/crates/ra_hir/src/nameres.rs b/crates/ra_hir/src/nameres.rs
index 97ce6c946..4573a72ba 100644
--- a/crates/ra_hir/src/nameres.rs
+++ b/crates/ra_hir/src/nameres.rs
@@ -16,9 +16,8 @@
 //! structure itself is modified.
 pub(crate) mod lower;
 
-use std::sync::Arc;
+use std::{time, sync::Arc};
 
-use ra_db::CrateId;
 use ra_arena::map::ArenaMap;
 use test_utils::tested_by;
 use rustc_hash::{FxHashMap, FxHashSet};
@@ -156,10 +155,10 @@ impl<T> PerNs<T> {
     }
 }
 
-pub(crate) struct Resolver<'a, DB> {
+struct Resolver<'a, DB> {
     db: &'a DB,
     input: &'a FxHashMap<ModuleId, Arc<LoweredModule>>,
-    krate: CrateId,
+    krate: Crate,
     module_tree: Arc<ModuleTree>,
     processed_imports: FxHashSet<(ModuleId, ImportId)>,
     result: ItemMap,
@@ -169,10 +168,10 @@ impl<'a, DB> Resolver<'a, DB>
 where
     DB: HirDatabase,
 {
-    pub(crate) fn new(
+    fn new(
         db: &'a DB,
         input: &'a FxHashMap<ModuleId, Arc<LoweredModule>>,
-        krate: CrateId,
+        krate: Crate,
     ) -> Resolver<'a, DB> {
         let module_tree = db.module_tree(krate);
         Resolver {
@@ -219,7 +218,7 @@ where
             let crate_graph = self.db.crate_graph();
             if let Some(crate_id) = crate_graph.crate_id_for_crate_root(file_id.as_original_file())
             {
-                let krate = Crate::new(crate_id);
+                let krate = Crate { crate_id };
                 for dep in krate.dependencies(self.db) {
                     if let Some(module) = dep.krate.root_module(self.db) {
                         let def = module.into();
@@ -331,6 +330,26 @@ enum ReachedFixedPoint {
 }
 
 impl ItemMap {
+    pub(crate) fn item_map_query(db: &impl HirDatabase, krate: Crate) -> Arc<ItemMap> {
+        let start = time::Instant::now();
+        let module_tree = db.module_tree(krate);
+        let input = module_tree
+            .modules()
+            .map(|module_id| {
+                (
+                    module_id,
+                    db.lower_module_module(Module { krate, module_id }),
+                )
+            })
+            .collect::<FxHashMap<_, _>>();
+
+        let resolver = Resolver::new(db, &input, krate);
+        let res = resolver.resolve();
+        let elapsed = start.elapsed();
+        log::info!("item_map: {:?}", elapsed);
+        Arc::new(res)
+    }
+
     pub(crate) fn resolve_path(
         &self,
         db: &impl HirDatabase,
diff --git a/crates/ra_hir/src/nameres/tests.rs b/crates/ra_hir/src/nameres/tests.rs
index e72781f51..9c5ca097e 100644
--- a/crates/ra_hir/src/nameres/tests.rs
+++ b/crates/ra_hir/src/nameres/tests.rs
@@ -16,7 +16,21 @@ fn item_map(fixture: &str) -> (Arc<ItemMap>, ModuleId) {
     let module = crate::source_binder::module_from_position(&db, pos).unwrap();
     let krate = module.krate(&db).unwrap();
     let module_id = module.module_id;
-    (db.item_map(krate.crate_id), module_id)
+    (db.item_map(krate), module_id)
+}
+
+/// Sets the crate root to the file of the cursor marker
+fn item_map_custom_crate_root(fixture: &str) -> (Arc<ItemMap>, ModuleId) {
+    let (mut db, pos) = MockDatabase::with_position(fixture);
+
+    let mut crate_graph = CrateGraph::default();
+    crate_graph.add_crate_root(pos.file_id);
+    db.set_crate_graph(Arc::new(crate_graph));
+
+    let module = crate::source_binder::module_from_position(&db, pos).unwrap();
+    let krate = module.krate(&db).unwrap();
+    let module_id = module.module_id;
+    (db.item_map(krate), module_id)
 }
 
 fn check_module_item_map(map: &ItemMap, module_id: ModuleId, expected: &str) {
@@ -134,6 +148,28 @@ fn re_exports() {
 }
 
 #[test]
+fn module_resolution_works_for_non_standard_filenames() {
+    let (item_map, module_id) = item_map_custom_crate_root(
+        "
+        //- /my_library.rs
+        mod foo;
+        use self::foo::Bar;
+        <|>
+        //- /foo/mod.rs
+        pub struct Bar;
+    ",
+    );
+    check_module_item_map(
+        &item_map,
+        module_id,
+        "
+            Bar: t v
+            foo: t
+        ",
+    );
+}
+
+#[test]
 fn name_res_works_for_broken_modules() {
     covers!(name_res_works_for_broken_modules);
     let (item_map, module_id) = item_map(
@@ -261,7 +297,7 @@ fn item_map_across_crates() {
 
     let module = crate::source_binder::module_from_file_id(&db, main_id).unwrap();
     let krate = module.krate(&db).unwrap();
-    let item_map = db.item_map(krate.crate_id);
+    let item_map = db.item_map(krate);
 
     check_module_item_map(
         &item_map,
@@ -313,7 +349,7 @@ fn import_across_source_roots() {
 
     let module = crate::source_binder::module_from_file_id(&db, main_id).unwrap();
     let krate = module.krate(&db).unwrap();
-    let item_map = db.item_map(krate.crate_id);
+    let item_map = db.item_map(krate);
 
     check_module_item_map(
         &item_map,
@@ -355,7 +391,7 @@ fn reexport_across_crates() {
 
     let module = crate::source_binder::module_from_file_id(&db, main_id).unwrap();
     let krate = module.krate(&db).unwrap();
-    let item_map = db.item_map(krate.crate_id);
+    let item_map = db.item_map(krate);
 
     check_module_item_map(
         &item_map,
@@ -373,7 +409,7 @@ fn check_item_map_is_not_recomputed(initial: &str, file_change: &str) {
     let krate = module.krate(&db).unwrap();
     {
         let events = db.log_executed(|| {
-            db.item_map(krate.crate_id);
+            db.item_map(krate);
         });
         assert!(format!("{:?}", events).contains("item_map"))
     }
@@ -381,7 +417,7 @@ fn check_item_map_is_not_recomputed(initial: &str, file_change: &str) {
 
     {
         let events = db.log_executed(|| {
-            db.item_map(krate.crate_id);
+            db.item_map(krate);
         });
         assert!(
             !format!("{:?}", events).contains("item_map"),
diff --git a/crates/ra_hir/src/query_definitions.rs b/crates/ra_hir/src/query_definitions.rs
index bf9ac0dfb..734a98282 100644
--- a/crates/ra_hir/src/query_definitions.rs
+++ b/crates/ra_hir/src/query_definitions.rs
@@ -1,25 +1,14 @@
-use std::{
-    sync::Arc,
-    time::Instant,
-};
+use std::sync::Arc;
 
-use rustc_hash::FxHashMap;
-use ra_syntax::{SyntaxNode, TreeArc};
-use ra_db::{CrateId};
+use ra_syntax::{
+    SyntaxNode, TreeArc,
+};
 
 use crate::{
     SourceFileItems, SourceItemId, HirFileId,
-    Function, FnScopes, Module,
     db::HirDatabase,
-    nameres::{ItemMap, Resolver},
 };
 
-pub(super) fn fn_scopes(db: &impl HirDatabase, func: Function) -> Arc<FnScopes> {
-    let body = db.body_hir(func);
-    let res = FnScopes::new(body);
-    Arc::new(res)
-}
-
 pub(super) fn file_items(db: &impl HirDatabase, file_id: HirFileId) -> Arc<SourceFileItems> {
     let source_file = db.hir_parse(file_id);
     let res = SourceFileItems::new(file_id, &source_file);
@@ -35,26 +24,3 @@ pub(super) fn file_item(
         .to_node(&source_file)
         .to_owned()
 }
-
-pub(super) fn item_map(db: &impl HirDatabase, crate_id: CrateId) -> Arc<ItemMap> {
-    let start = Instant::now();
-    let module_tree = db.module_tree(crate_id);
-    let input = module_tree
-        .modules()
-        .map(|module_id| {
-            (
-                module_id,
-                db.lower_module_module(Module {
-                    krate: crate_id,
-                    module_id,
-                }),
-            )
-        })
-        .collect::<FxHashMap<_, _>>();
-
-    let resolver = Resolver::new(db, &input, crate_id);
-    let res = resolver.resolve();
-    let elapsed = start.elapsed();
-    log::info!("item_map: {:?}", elapsed);
-    Arc::new(res)
-}
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index f523f0647..d1eaccf23 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -13,8 +13,8 @@ use ra_syntax::{
 };
 
 use crate::{
-    HirDatabase, Function, ModuleDef,
-    AsName, Module, HirFileId,
+    HirDatabase, Function, ModuleDef, Struct, Enum,
+    AsName, Module, HirFileId, Crate,
     ids::{LocationCtx, SourceFileItemId},
 };
 
@@ -83,7 +83,8 @@ fn module_from_source(
     let source_root_id = db.file_source_root(file_id.as_original_file());
     db.source_root_crates(source_root_id)
         .iter()
-        .find_map(|&krate| {
+        .map(|&crate_id| Crate { crate_id })
+        .find_map(|krate| {
             let module_tree = db.module_tree(krate);
             let module_id = module_tree.find_module_by_source(file_id, decl_id)?;
             Some(Module { krate, module_id })
@@ -128,6 +129,28 @@ pub fn function_from_child_node(
     function_from_source(db, file_id, fn_def)
 }
 
+pub fn struct_from_module(
+    db: &impl HirDatabase,
+    module: Module,
+    struct_def: &ast::StructDef,
+) -> Struct {
+    let (file_id, _) = module.definition_source(db);
+    let file_id = file_id.into();
+    let ctx = LocationCtx::new(db, module, file_id);
+    Struct {
+        id: ctx.to_def(struct_def),
+    }
+}
+
+pub fn enum_from_module(db: &impl HirDatabase, module: Module, enum_def: &ast::EnumDef) -> Enum {
+    let (file_id, _) = module.definition_source(db);
+    let file_id = file_id.into();
+    let ctx = LocationCtx::new(db, module, file_id);
+    Enum {
+        id: ctx.to_def(enum_def),
+    }
+}
+
 pub fn macro_symbols(db: &impl HirDatabase, file_id: FileId) -> Vec<(SmolStr, TextRange)> {
     let module = match module_from_file_id(db, file_id) {
         Some(it) => it,
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index 31ea45706..60c231e82 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -20,6 +20,7 @@ mod tests;
 pub(crate) mod method_resolution;
 
 use std::borrow::Cow;
+use std::iter::repeat;
 use std::ops::Index;
 use std::sync::Arc;
 use std::{fmt, mem};
@@ -33,7 +34,7 @@ use test_utils::tested_by;
 
 use crate::{
     Module, Function, Struct, StructField, Enum, EnumVariant, Path, Name, ImplBlock,
-    FnSignature, FnScopes, ModuleDef, AdtDef,
+    FnSignature, ExprScopes, ModuleDef, AdtDef,
     db::HirDatabase,
     type_ref::{TypeRef, Mutability},
     name::KnownName,
@@ -185,7 +186,7 @@ pub enum Ty {
 
     /// Structures, enumerations and unions.
     Adt {
-        /// The DefId of the struct/enum.
+        /// The definition of the struct/enum.
         def_id: AdtDef,
         /// The name, for displaying.
         name: Name,
@@ -209,6 +210,27 @@ pub enum Ty {
     /// `&'a mut T` or `&'a T`.
     Ref(Arc<Ty>, 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}`.
+    ///
+    /// For example the type of `bar` here:
+    ///
+    /// ```rust
+    /// fn foo() -> i32 { 1 }
+    /// let bar = foo; // bar: fn() -> i32 {foo}
+    /// ```
+    FnDef {
+        // Function definition
+        def: Function,
+        /// For display
+        name: Name,
+        /// Parameters and return type
+        sig: Arc<FnSig>,
+        /// Substitutions for the generic parameters of the type
+        substs: Substs,
+    },
+
     /// A pointer to a function.  Written as `fn() -> i32`.
     ///
     /// For example the type of `bar` here:
@@ -448,12 +470,12 @@ impl Ty {
         }
         // add placeholders for args that were not provided
         // TODO: handle defaults
-        for _ in segment
+        let supplied_params = segment
             .args_and_bindings
             .as_ref()
             .map(|ga| ga.args.len())
-            .unwrap_or(0)..def_generics.params.len()
-        {
+            .unwrap_or(0);
+        for _ in supplied_params..def_generics.params.len() {
             substs.push(Ty::Unknown);
         }
         assert_eq!(substs.len(), def_generics.params.len());
@@ -485,6 +507,19 @@ impl Ty {
                 }
                 sig_mut.output.walk_mut(f);
             }
+            Ty::FnDef { substs, sig, .. } => {
+                let sig_mut = Arc::make_mut(sig);
+                for input in &mut sig_mut.input {
+                    input.walk_mut(f);
+                }
+                sig_mut.output.walk_mut(f);
+                // Without an Arc::make_mut_slice, we can't avoid the clone here:
+                let mut v: Vec<_> = substs.0.iter().cloned().collect();
+                for t in &mut v {
+                    t.walk_mut(f);
+                }
+                substs.0 = v.into();
+            }
             Ty::Adt { substs, .. } => {
                 // Without an Arc::make_mut_slice, we can't avoid the clone here:
                 let mut v: Vec<_> = substs.0.iter().cloned().collect();
@@ -524,6 +559,12 @@ impl Ty {
                 name,
                 substs,
             },
+            Ty::FnDef { def, name, sig, .. } => Ty::FnDef {
+                def,
+                name,
+                sig,
+                substs,
+            },
             _ => self,
         }
     }
@@ -551,7 +592,7 @@ impl Ty {
     /// or function); so if `self` is `Option<u32>`, this returns the `u32`.
     fn substs(&self) -> Option<Substs> {
         match self {
-            Ty::Adt { substs, .. } => Some(substs.clone()),
+            Ty::Adt { substs, .. } | Ty::FnDef { substs, .. } => Some(substs.clone()),
             _ => None,
         }
     }
@@ -586,6 +627,22 @@ impl fmt::Display for Ty {
                     .to_fmt(f)?;
                 write!(f, " -> {}", sig.output)
             }
+            Ty::FnDef {
+                name, substs, sig, ..
+            } => {
+                write!(f, "fn {}", name)?;
+                if substs.0.len() > 0 {
+                    join(substs.0.iter())
+                        .surround_with("<", ">")
+                        .separator(", ")
+                        .to_fmt(f)?;
+                }
+                join(sig.input.iter())
+                    .surround_with("(", ")")
+                    .separator(", ")
+                    .to_fmt(f)?;
+                write!(f, " -> {}", sig.output)
+            }
             Ty::Adt { name, substs, .. } => {
                 write!(f, "{}", name)?;
                 if substs.0.len() > 0 {
@@ -607,11 +664,11 @@ impl fmt::Display for Ty {
 
 /// Compute the declared type of a function. This should not need to look at the
 /// function body.
-fn type_for_fn(db: &impl HirDatabase, f: Function) -> Ty {
-    let signature = f.signature(db);
-    let module = f.module(db);
-    let impl_block = f.impl_block(db);
-    let generics = f.generic_params(db);
+fn type_for_fn(db: &impl HirDatabase, def: Function) -> Ty {
+    let signature = def.signature(db);
+    let module = def.module(db);
+    let impl_block = def.impl_block(db);
+    let generics = def.generic_params(db);
     let input = signature
         .params()
         .iter()
@@ -624,8 +681,15 @@ fn type_for_fn(db: &impl HirDatabase, f: Function) -> Ty {
         &generics,
         signature.ret_type(),
     );
-    let sig = FnSig { input, output };
-    Ty::FnPtr(Arc::new(sig))
+    let sig = Arc::new(FnSig { input, output });
+    let substs = make_substs(&generics);
+    let name = def.name(db);
+    Ty::FnDef {
+        def,
+        sig,
+        name,
+        substs,
+    }
 }
 
 fn make_substs(generics: &GenericParams) -> Substs {
@@ -750,7 +814,7 @@ impl Index<PatId> for InferenceResult {
 struct InferenceContext<'a, D: HirDatabase> {
     db: &'a D,
     body: Arc<Body>,
-    scopes: Arc<FnScopes>,
+    scopes: Arc<ExprScopes>,
     module: Module,
     impl_block: Option<ImplBlock>,
     var_unification_table: InPlaceUnificationTable<TypeVarId>,
@@ -844,7 +908,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     fn new(
         db: &'a D,
         body: Arc<Body>,
-        scopes: Arc<FnScopes>,
+        scopes: Arc<ExprScopes>,
         module: Module,
         impl_block: Option<ImplBlock>,
     ) -> Self {
@@ -1102,7 +1166,18 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             .into();
         let typable = typable?;
         let ty = self.db.type_for_def(typable);
+        let generics = GenericParams::default();
+        let substs = Ty::substs_from_path(
+            self.db,
+            &self.module,
+            self.impl_block.as_ref(),
+            &generics,
+            path,
+            typable,
+        );
+        let ty = ty.apply_substs(substs);
         let ty = self.insert_type_vars(ty);
+
         Some(ty)
     }
 
@@ -1142,7 +1217,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 let ty = self.insert_type_vars(ty.apply_substs(substs));
                 (ty, Some(var.into()))
             }
-            TypableDef::Enum(_) | TypableDef::Function(_) => (Ty::Unknown, None),
+            TypableDef::Function(_) | TypableDef::Enum(_) => (Ty::Unknown, None),
         }
     }
 
@@ -1196,9 +1271,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     Ty::Tuple(ref tuple_args) => &**tuple_args,
                     _ => &[],
                 };
-                let expectations_iter = expectations
-                    .into_iter()
-                    .chain(std::iter::repeat(&Ty::Unknown));
+                let expectations_iter = expectations.into_iter().chain(repeat(&Ty::Unknown));
 
                 let inner_tys = args
                     .iter()
@@ -1332,18 +1405,25 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             Expr::Call { callee, args } => {
                 let callee_ty = self.infer_expr(*callee, &Expectation::none());
                 let (param_tys, ret_ty) = match &callee_ty {
-                    Ty::FnPtr(sig) => (&sig.input[..], sig.output.clone()),
+                    Ty::FnPtr(sig) => (sig.input.clone(), sig.output.clone()),
+                    Ty::FnDef { substs, sig, .. } => {
+                        let ret_ty = sig.output.clone().subst(&substs);
+                        let param_tys = sig
+                            .input
+                            .iter()
+                            .map(|ty| ty.clone().subst(&substs))
+                            .collect();
+                        (param_tys, ret_ty)
+                    }
                     _ => {
                         // not callable
                         // TODO report an error?
-                        (&[][..], Ty::Unknown)
+                        (Vec::new(), Ty::Unknown)
                     }
                 };
-                for (i, arg) in args.iter().enumerate() {
-                    self.infer_expr(
-                        *arg,
-                        &Expectation::has_type(param_tys.get(i).cloned().unwrap_or(Ty::Unknown)),
-                    );
+                let param_iter = param_tys.into_iter().chain(repeat(Ty::Unknown));
+                for (arg, param) in args.iter().zip(param_iter) {
+                    self.infer_expr(*arg, &Expectation::has_type(param));
                 }
                 ret_ty
             }
@@ -1365,21 +1445,34 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 let (expected_receiver_ty, param_tys, ret_ty) = match &method_ty {
                     Ty::FnPtr(sig) => {
                         if sig.input.len() > 0 {
-                            (&sig.input[0], &sig.input[1..], sig.output.clone())
+                            (
+                                sig.input[0].clone(),
+                                sig.input[1..].iter().cloned().collect(),
+                                sig.output.clone(),
+                            )
+                        } else {
+                            (Ty::Unknown, Vec::new(), sig.output.clone())
+                        }
+                    }
+                    Ty::FnDef { substs, sig, .. } => {
+                        let ret_ty = sig.output.clone().subst(&substs);
+
+                        if sig.input.len() > 0 {
+                            let mut arg_iter = sig.input.iter().map(|ty| ty.clone().subst(&substs));
+                            let receiver_ty = arg_iter.next().unwrap();
+                            (receiver_ty, arg_iter.collect(), ret_ty)
                         } else {
-                            (&Ty::Unknown, &[][..], sig.output.clone())
+                            (Ty::Unknown, Vec::new(), ret_ty)
                         }
                     }
-                    _ => (&Ty::Unknown, &[][..], Ty::Unknown),
+                    _ => (Ty::Unknown, Vec::new(), Ty::Unknown),
                 };
                 // TODO we would have to apply the autoderef/autoref steps here
                 // to get the correct receiver type to unify...
-                self.unify(expected_receiver_ty, &receiver_ty);
-                for (i, arg) in args.iter().enumerate() {
-                    self.infer_expr(
-                        *arg,
-                        &Expectation::has_type(param_tys.get(i).cloned().unwrap_or(Ty::Unknown)),
-                    );
+                self.unify(&expected_receiver_ty, &receiver_ty);
+                let param_iter = param_tys.into_iter().chain(repeat(Ty::Unknown));
+                for (arg, param) in args.iter().zip(param_iter) {
+                    self.infer_expr(*arg, &Expectation::has_type(param));
                 }
                 ret_ty
             }
@@ -1395,7 +1488,9 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     for &pat in &arm.pats {
                         let _pat_ty = self.infer_pat(pat, &input_ty);
                     }
-                    // TODO type the guard
+                    if let Some(guard_expr) = arm.guard {
+                        self.infer_expr(guard_expr, &Expectation::has_type(Ty::Bool));
+                    }
                     self.infer_expr(arm.expr, &expected);
                 }
 
@@ -1468,9 +1563,17 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 cast_ty
             }
             Expr::Ref { expr, mutability } => {
-                // TODO pass the expectation down
-                let inner_ty = self.infer_expr(*expr, &Expectation::none());
+                let expectation = if let Ty::Ref(ref subty, expected_mutability) = expected.ty {
+                    if expected_mutability == Mutability::Mut && *mutability == Mutability::Shared {
+                        // TODO: throw type error - expected mut reference but found shared ref,
+                        // which cannot be coerced
+                    }
+                    Expectation::has_type((**subty).clone())
+                } else {
+                    Expectation::none()
+                };
                 // TODO reference coercions etc.
+                let inner_ty = self.infer_expr(*expr, &expectation);
                 Ty::Ref(Arc::new(inner_ty), *mutability)
             }
             Expr::UnaryOp { expr, op } => {
@@ -1495,9 +1598,13 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                             _ => Ty::Unknown,
                         }
                     }
-                    UnaryOp::Not if inner_ty == Ty::Bool => Ty::Bool,
-                    // TODO: resolve ops::Not trait for inner_ty
-                    UnaryOp::Not => Ty::Unknown,
+                    UnaryOp::Not => {
+                        match inner_ty {
+                            Ty::Bool | Ty::Int(_) | Ty::Infer(InferTy::IntVar(..)) => inner_ty,
+                            // TODO: resolve ops::Not trait for inner_ty
+                            _ => Ty::Unknown,
+                        }
+                    }
                 }
             }
             Expr::BinaryOp { lhs, rhs, op } => match op {
@@ -1609,10 +1716,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
             self.infer_pat(*pat, &ty);
         }
-        self.return_ty = {
-            let ty = self.make_ty(signature.ret_type());
-            ty
-        };
+        self.return_ty = self.make_ty(signature.ret_type());
     }
 
     fn infer_body(&mut self) {
@@ -1626,7 +1730,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 pub fn infer(db: &impl HirDatabase, func: Function) -> Arc<InferenceResult> {
     db.check_canceled();
     let body = func.body(db);
-    let scopes = db.fn_scopes(func);
+    let scopes = db.expr_scopes(func);
     let module = func.module(db);
     let impl_block = func.impl_block(db);
     let mut ctx = InferenceContext::new(db, body, scopes, module, impl_block);
diff --git a/crates/ra_hir/src/ty/method_resolution.rs b/crates/ra_hir/src/ty/method_resolution.rs
index 9a571c2aa..37bc3f38c 100644
--- a/crates/ra_hir/src/ty/method_resolution.rs
+++ b/crates/ra_hir/src/ty/method_resolution.rs
@@ -44,7 +44,7 @@ impl CrateImplBlocks {
         &'a self,
         db: &'a impl HirDatabase,
         ty: &Ty,
-    ) -> impl Iterator<Item = ImplBlock> + 'a {
+    ) -> impl Iterator<Item = (Module, ImplBlock)> + 'a {
         let fingerprint = TyFingerprint::for_impl(ty);
         fingerprint
             .and_then(|f| self.impls.get(&f))
@@ -52,11 +52,11 @@ impl CrateImplBlocks {
             .flat_map(|i| i.iter())
             .map(move |(module_id, impl_id)| {
                 let module = Module {
-                    krate: self.krate.crate_id,
+                    krate: self.krate,
                     module_id: *module_id,
                 };
                 let module_impl_blocks = db.impls_in_module(module);
-                ImplBlock::from_id(module_impl_blocks, *impl_id)
+                (module, ImplBlock::from_id(module_impl_blocks, *impl_id))
             })
     }
 
@@ -152,7 +152,7 @@ impl Ty {
             };
             let impls = db.impls_in_crate(krate);
 
-            for impl_block in impls.lookup_impl_blocks(db, &derefed_ty) {
+            for (_, impl_block) in impls.lookup_impl_blocks(db, &derefed_ty) {
                 for item in impl_block.items() {
                     match item {
                         ImplItem::Method(f) => {
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_adt_pattern.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_adt_pattern.snap
index 2719f592e..48c83cbb2 100644
--- a/crates/ra_hir/src/ty/snapshots/tests__infer_adt_pattern.snap
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_adt_pattern.snap
@@ -1,10 +1,10 @@
 ---
-created: "2019-01-22T14:44:59.880187500+00:00"
-creator: insta@0.4.0
+created: "2019-01-28T21:58:55.559331849+00:00"
+creator: insta@0.5.2
 expression: "&result"
-source: "crates\\ra_hir\\src\\ty\\tests.rs"
+source: crates/ra_hir/src/ty/tests.rs
 ---
-[68; 262) '{     ...  d; }': ()
+[68; 289) '{     ...  d; }': ()
 [78; 79) 'e': E
 [82; 95) 'E::A { x: 3 }': E
 [92; 93) '3': usize
@@ -15,15 +15,18 @@ source: "crates\\ra_hir\\src\\ty\\tests.rs"
 [129; 148) 'E::A {..._var }': E
 [139; 146) 'new_var': usize
 [151; 152) 'e': E
-[159; 218) 'match ...     }': usize
+[159; 245) 'match ...     }': usize
 [165; 166) 'e': E
 [177; 187) 'E::A { x }': E
 [184; 185) 'x': usize
 [191; 192) 'x': usize
 [202; 206) 'E::B': E
-[210; 211) '1': usize
-[229; 248) 'ref d ...{ .. }': &E
-[237; 248) 'E::A { .. }': E
-[251; 252) 'e': E
-[258; 259) 'd': &E
+[210; 213) 'foo': bool
+[217; 218) '1': usize
+[228; 232) 'E::B': E
+[236; 238) '10': usize
+[256; 275) 'ref d ...{ .. }': &E
+[264; 275) 'E::A { .. }': E
+[278; 279) 'e': E
+[285; 286) 'd': &E
 
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_array.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_array.snap
index 3f2faa598..042248c35 100644
--- a/crates/ra_hir/src/ty/snapshots/tests__infer_array.snap
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_array.snap
@@ -1,12 +1,12 @@
 ---
-created: "2019-01-22T14:44:59.880187500+00:00"
-creator: insta@0.4.0
+created: "2019-01-30T20:08:05.185312835+00:00"
+creator: insta@0.5.2
 expression: "&result"
-source: "crates\\ra_hir\\src\\ty\\tests.rs"
+source: crates/ra_hir/src/ty/tests.rs
 ---
 [9; 10) 'x': &str
 [18; 19) 'y': isize
-[28; 293) '{     ... []; }': ()
+[28; 324) '{     ... 3]; }': ()
 [38; 39) 'a': [&str]
 [42; 45) '[x]': [&str]
 [43; 44) 'x': &str
@@ -56,4 +56,10 @@ source: "crates\\ra_hir\\src\\ty\\tests.rs"
 [260; 263) '"b"': &str
 [275; 276) 'x': [u8]
 [288; 290) '[]': [u8]
+[300; 301) 'z': &[u8]
+[311; 321) '&[1, 2, 3]': &[u8]
+[312; 321) '[1, 2, 3]': [u8]
+[313; 314) '1': u8
+[316; 317) '2': u8
+[319; 320) '3': u8
 
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_backwards.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_backwards.snap
index 5c74bd8c7..f5840a934 100644
--- a/crates/ra_hir/src/ty/snapshots/tests__infer_backwards.snap
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_backwards.snap
@@ -1,8 +1,8 @@
 ---
-created: "2019-01-22T14:44:59.880187500+00:00"
-creator: insta@0.4.0
+created: "2019-01-26T17:46:03.842478456+00:00"
+creator: insta@0.5.2
 expression: "&result"
-source: "crates\\ra_hir\\src\\ty\\tests.rs"
+source: crates/ra_hir/src/ty/tests.rs
 ---
 [14; 15) 'x': u32
 [22; 24) '{}': ()
@@ -10,7 +10,7 @@ source: "crates\\ra_hir\\src\\ty\\tests.rs"
 [88; 89) 'a': u32
 [92; 108) 'unknow...nction': [unknown]
 [92; 110) 'unknow...tion()': u32
-[116; 125) 'takes_u32': fn(u32) -> ()
+[116; 125) 'takes_u32': fn takes_u32(u32) -> ()
 [116; 128) 'takes_u32(a)': ()
 [126; 127) 'a': u32
 [138; 139) 'b': i32
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_binary_op.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_binary_op.snap
index c506bcadd..b9dda2bc0 100644
--- a/crates/ra_hir/src/ty/snapshots/tests__infer_binary_op.snap
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_binary_op.snap
@@ -1,8 +1,8 @@
 ---
-created: "2019-01-22T14:44:59.880187500+00:00"
-creator: insta@0.4.0
+created: "2019-01-26T17:46:03.853259898+00:00"
+creator: insta@0.5.2
 expression: "&result"
-source: "crates\\ra_hir\\src\\ty\\tests.rs"
+source: crates/ra_hir/src/ty/tests.rs
 ---
 [6; 7) 'x': bool
 [22; 34) '{     0i32 }': i32
@@ -28,7 +28,7 @@ source: "crates\\ra_hir\\src\\ty\\tests.rs"
 [174; 196) 'minus_...ONST_2': bool
 [189; 196) 'CONST_2': isize
 [206; 207) 'c': i32
-[210; 211) 'f': fn(bool) -> i32
+[210; 211) 'f': fn f(bool) -> i32
 [210; 219) 'f(z || y)': i32
 [210; 223) 'f(z || y) + 5': i32
 [212; 213) 'z': bool
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_function_generics.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_function_generics.snap
index 7203ad1e2..8ff6e55a6 100644
--- a/crates/ra_hir/src/ty/snapshots/tests__infer_function_generics.snap
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_function_generics.snap
@@ -1,21 +1,21 @@
 ---
-created: "2019-01-22T14:44:59.954958500+00:00"
-creator: insta@0.4.0
+created: "2019-01-26T18:16:16.530712344+00:00"
+creator: insta@0.5.2
 expression: "&result"
-source: "crates\\ra_hir\\src\\ty\\tests.rs"
+source: crates/ra_hir/src/ty/tests.rs
 ---
 [10; 11) 't': [unknown]
 [21; 26) '{ t }': [unknown]
 [23; 24) 't': [unknown]
 [38; 98) '{     ...(1); }': ()
-[44; 46) 'id': fn(T) -> T
-[44; 52) 'id(1u32)': T
+[44; 46) 'id': fn id<u32>(T) -> T
+[44; 52) 'id(1u32)': u32
 [47; 51) '1u32': u32
-[58; 68) 'id::<i128>': fn(T) -> T
-[58; 71) 'id::<i128>(1)': T
-[69; 70) '1': T
-[81; 82) 'x': T
-[90; 92) 'id': fn(T) -> T
-[90; 95) 'id(1)': T
-[93; 94) '1': T
+[58; 68) 'id::<i128>': fn id<i128>(T) -> T
+[58; 71) 'id::<i128>(1)': i128
+[69; 70) '1': i128
+[81; 82) 'x': u64
+[90; 92) 'id': fn id<u64>(T) -> T
+[90; 95) 'id(1)': u64
+[93; 94) '1': u64
 
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_generic_chain.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_generic_chain.snap
index 4435180a1..f21bffa75 100644
--- a/crates/ra_hir/src/ty/snapshots/tests__infer_generic_chain.snap
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_generic_chain.snap
@@ -1,8 +1,8 @@
 ---
-created: "2019-01-22T14:44:59.961936900+00:00"
-creator: insta@0.4.0
+created: "2019-01-26T17:46:03.866825843+00:00"
+creator: insta@0.5.2
 expression: "&result"
-source: "crates\\ra_hir\\src\\ty\\tests.rs"
+source: crates/ra_hir/src/ty/tests.rs
 ---
 [53; 57) 'self': A<[unknown]>
 [65; 87) '{     ...     }': [unknown]
@@ -12,25 +12,25 @@ source: "crates\\ra_hir\\src\\ty\\tests.rs"
 [110; 115) '{ t }': [unknown]
 [112; 113) 't': [unknown]
 [135; 261) '{     ....x() }': i128
-[146; 147) 'x': T
-[150; 151) '1': T
-[162; 163) 'y': T
-[166; 168) 'id': fn(T) -> T
-[166; 171) 'id(x)': T
-[169; 170) 'x': T
-[182; 183) 'a': A<T>
-[186; 200) 'A { x: id(y) }': A<T>
-[193; 195) 'id': fn(T) -> T
-[193; 198) 'id(y)': T
-[196; 197) 'y': T
-[211; 212) 'z': T
-[215; 217) 'id': fn(T) -> T
-[215; 222) 'id(a.x)': T
-[218; 219) 'a': A<T>
-[218; 221) 'a.x': T
-[233; 234) 'b': A<T>
-[237; 247) 'A { x: z }': A<T>
-[244; 245) 'z': T
-[254; 255) 'b': A<T>
+[146; 147) 'x': i32
+[150; 151) '1': i32
+[162; 163) 'y': i32
+[166; 168) 'id': fn id<i32>(T) -> T
+[166; 171) 'id(x)': i32
+[169; 170) 'x': i32
+[182; 183) 'a': A<i32>
+[186; 200) 'A { x: id(y) }': A<i32>
+[193; 195) 'id': fn id<i32>(T) -> T
+[193; 198) 'id(y)': i32
+[196; 197) 'y': i32
+[211; 212) 'z': i32
+[215; 217) 'id': fn id<i32>(T) -> T
+[215; 222) 'id(a.x)': i32
+[218; 219) 'a': A<i32>
+[218; 221) 'a.x': i32
+[233; 234) 'b': A<i32>
+[237; 247) 'A { x: z }': A<i32>
+[244; 245) 'z': i32
+[254; 255) 'b': A<i32>
 [254; 259) 'b.x()': i128
 
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_paths.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_paths.snap
index 0bceffaef..afbe2f747 100644
--- a/crates/ra_hir/src/ty/snapshots/tests__infer_paths.snap
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_paths.snap
@@ -1,16 +1,16 @@
 ---
-created: "2019-01-22T14:44:59.975899500+00:00"
-creator: insta@0.4.0
+created: "2019-01-26T17:46:03.928773630+00:00"
+creator: insta@0.5.2
 expression: "&result"
-source: "crates\\ra_hir\\src\\ty\\tests.rs"
+source: crates/ra_hir/src/ty/tests.rs
 ---
 [15; 20) '{ 1 }': u32
 [17; 18) '1': u32
 [48; 53) '{ 1 }': u32
 [50; 51) '1': u32
 [67; 91) '{     ...c(); }': ()
-[73; 74) 'a': fn() -> u32
+[73; 74) 'a': fn a() -> u32
 [73; 76) 'a()': u32
-[82; 86) 'b::c': fn() -> u32
+[82; 86) 'b::c': fn c() -> u32
 [82; 88) 'b::c()': u32
 
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_type_param.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_type_param.snap
new file mode 100644
index 000000000..a99323264
--- /dev/null
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_type_param.snap
@@ -0,0 +1,26 @@
+---
+created: "2019-01-27T16:54:18.368427685+00:00"
+creator: [email protected]
+expression: "&result"
+source: crates/ra_hir/src/ty/tests.rs
+---
+[10; 11) 'x': [unknown]
+[21; 30) '{     x }': [unknown]
+[27; 28) 'x': [unknown]
+[44; 45) 'x': &[unknown]
+[56; 65) '{     x }': &[unknown]
+[62; 63) 'x': &[unknown]
+[77; 157) '{     ...(1); }': ()
+[87; 88) 'y': u32
+[91; 96) '10u32': u32
+[102; 104) 'id': fn id<u32>(T) -> T
+[102; 107) 'id(y)': u32
+[105; 106) 'y': u32
+[117; 118) 'x': bool
+[127; 132) 'clone': fn clone<bool>(&T) -> T
+[127; 135) 'clone(z)': bool
+[133; 134) 'z': &bool
+[141; 151) 'id::<i128>': fn id<i128>(T) -> T
+[141; 154) 'id::<i128>(1)': i128
+[152; 153) '1': i128
+
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_unary_op.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_unary_op.snap
index 10aa61954..5021d0eeb 100644
--- a/crates/ra_hir/src/ty/snapshots/tests__infer_unary_op.snap
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_unary_op.snap
@@ -1,11 +1,11 @@
 ---
-created: "2019-01-22T14:45:00.059676600+00:00"
-creator: insta@0.4.0
+created: "2019-01-28T14:51:16.185273502+00:00"
+creator: insta@0.5.2
 expression: "&result"
-source: "crates\\ra_hir\\src\\ty\\tests.rs"
+source: crates/ra_hir/src/ty/tests.rs
 ---
 [27; 28) 'x': SomeType
-[40; 197) '{     ...lo"; }': ()
+[40; 272) '{     ...lo"; }': ()
 [50; 51) 'b': bool
 [54; 59) 'false': bool
 [69; 70) 'c': bool
@@ -24,12 +24,25 @@ source: "crates\\ra_hir\\src\\ty\\tests.rs"
 [147; 153) '!!true': bool
 [148; 153) '!true': bool
 [149; 153) 'true': bool
-[159; 164) '-3.14': f64
-[160; 164) '3.14': f64
-[170; 172) '-x': [unknown]
-[171; 172) 'x': SomeType
-[178; 180) '!x': [unknown]
-[179; 180) 'x': SomeType
-[186; 194) '-"hello"': [unknown]
-[187; 194) '"hello"': &str
+[163; 164) 'g': i32
+[167; 170) '!42': i32
+[168; 170) '42': i32
+[180; 181) 'h': u32
+[184; 190) '!10u32': u32
+[185; 190) '10u32': u32
+[200; 201) 'j': i128
+[204; 206) '!a': i128
+[205; 206) 'a': i128
+[212; 217) '-3.14': f64
+[213; 217) '3.14': f64
+[223; 225) '!3': i32
+[224; 225) '3': i32
+[231; 233) '-x': [unknown]
+[232; 233) 'x': SomeType
+[239; 241) '!x': [unknown]
+[240; 241) 'x': SomeType
+[247; 255) '-"hello"': [unknown]
+[248; 255) '"hello"': &str
+[261; 269) '!"hello"': [unknown]
+[262; 269) '"hello"': &str
 
diff --git a/crates/ra_hir/src/ty/tests.rs b/crates/ra_hir/src/ty/tests.rs
index f74d6f5ea..cb8d6351d 100644
--- a/crates/ra_hir/src/ty/tests.rs
+++ b/crates/ra_hir/src/ty/tests.rs
@@ -166,10 +166,15 @@ fn test(x: SomeType) {
     let d: i128 = -a;
     let e = -100;
     let f = !!!true;
+    let g = !42;
+    let h = !10u32;
+    let j = !a;
     -3.14;
+    !3;
     -x;
     !x;
     -"hello";
+    !"hello";
 }
 "#,
     );
@@ -366,6 +371,7 @@ fn test(x: &str, y: isize) {
 
     let b = [a, ["b"]];
     let x: [u8; 0] = [];
+    let z: &[u8] = &[1, 2, 3];
 }
 "#,
     );
@@ -421,7 +427,8 @@ fn test() {
 
     match e {
         E::A { x } => x,
-        E::B => 1,
+        E::B if foo => 1,
+        E::B => 10,
     };
 
     let ref d @ E::A { .. } = e;
@@ -594,6 +601,29 @@ fn test() {
     );
 }
 
+#[test]
+fn infer_type_param() {
+    check_inference(
+        "infer_type_param",
+        r#"
+fn id<T>(x: T) -> T {
+    x
+}
+
+fn clone<T>(x: &T) -> T {
+    x
+}
+
+fn test() {
+    let y = 10u32;
+    id(y);
+    let x: bool = clone(z);
+    id::<i128>(1);
+}
+"#,
+    );
+}
+
 fn infer(content: &str) -> String {
     let (db, _, file_id) = MockDatabase::with_single_file(content);
     let source_file = db.parse(file_id);
diff --git a/crates/ra_ide_api/Cargo.toml b/crates/ra_ide_api/Cargo.toml
index 79e473463..908899129 100644
--- a/crates/ra_ide_api/Cargo.toml
+++ b/crates/ra_ide_api/Cargo.toml
@@ -15,6 +15,9 @@ rustc-hash = "1.0"
 parking_lot = "0.7.0"
 unicase = "2.2.0"
 
+jemallocator = { version = "0.1.9", optional = true }
+jemalloc-ctl = { version = "0.2.0", optional = true }
+
 ra_syntax = { path = "../ra_syntax" }
 ra_ide_api_light = { path = "../ra_ide_api_light" }
 ra_text_edit = { path = "../ra_text_edit" }
@@ -24,3 +27,6 @@ test_utils = { path = "../test_utils" }
 
 [dev-dependencies]
 insta = "0.5.1"
+
+[features]
+jemalloc = [ "jemallocator", "jemalloc-ctl" ]
diff --git a/crates/ra_ide_api/src/call_info.rs b/crates/ra_ide_api/src/call_info.rs
index ee1e13799..2eb388e0e 100644
--- a/crates/ra_ide_api/src/call_info.rs
+++ b/crates/ra_ide_api/src/call_info.rs
@@ -3,9 +3,10 @@ use ra_db::SourceDatabase;
 use ra_syntax::{
     AstNode, SyntaxNode, TextUnit, TextRange,
     SyntaxKind::FN_DEF,
-    ast::{self, ArgListOwner, DocCommentsOwner},
+    ast::{self, ArgListOwner},
     algo::find_node_at_offset,
 };
+use hir::Docs;
 
 use crate::{FilePosition, CallInfo, db::RootDatabase};
 
@@ -26,7 +27,9 @@ pub(crate) fn call_info(db: &RootDatabase, position: FilePosition) -> Option<Cal
     let fn_file = db.parse(symbol.file_id);
     let fn_def = symbol.ptr.to_node(&fn_file);
     let fn_def = ast::FnDef::cast(fn_def).unwrap();
-    let mut call_info = CallInfo::new(fn_def)?;
+    let function = hir::source_binder::function_from_source(db, symbol.file_id, fn_def)?;
+
+    let mut call_info = CallInfo::new(db, function, fn_def)?;
     // If we have a calling expression let's find which argument we are on
     let num_params = call_info.parameters.len();
     let has_self = fn_def.param_list().and_then(|l| l.self_param()).is_some();
@@ -110,46 +113,13 @@ impl<'a> FnCallNode<'a> {
 }
 
 impl CallInfo {
-    fn new(node: &ast::FnDef) -> Option<Self> {
-        let label: String = if let Some(body) = node.body() {
-            let body_range = body.syntax().range();
-            let label: String = node
-                .syntax()
-                .children()
-                .filter(|child| !child.range().is_subrange(&body_range)) // Filter out body
-                .filter(|child| ast::Comment::cast(child).is_none()) // Filter out doc comments
-                .map(|node| node.text().to_string())
-                .collect();
-            label
-        } else {
-            node.syntax().text().to_string()
-        };
-
-        let mut doc = None;
-        if let Some(docs) = node.doc_comment_text() {
-            // Massage markdown
-            let mut processed_lines = Vec::new();
-            let mut in_code_block = false;
-            for line in docs.lines() {
-                if line.starts_with("```") {
-                    in_code_block = !in_code_block;
-                }
-
-                let line = if in_code_block && line.starts_with("```") && !line.contains("rust") {
-                    "```rust".into()
-                } else {
-                    line.to_string()
-                };
-
-                processed_lines.push(line);
-            }
-
-            doc = Some(processed_lines.join("\n"));
-        }
+    fn new(db: &RootDatabase, function: hir::Function, node: &ast::FnDef) -> Option<Self> {
+        let label = crate::completion::function_label(node)?;
+        let doc = function.docs(db);
 
         Some(CallInfo {
             parameters: param_list(node),
-            label: label.trim().to_owned(),
+            label,
             doc,
             active_parameter: None,
         })
@@ -284,7 +254,7 @@ fn bar() {
         assert_eq!(info.parameters, vec!["j".to_string()]);
         assert_eq!(info.active_parameter, Some(0));
         assert_eq!(info.label, "fn foo(j: u32) -> u32".to_string());
-        assert_eq!(info.doc, Some("test".into()));
+        assert_eq!(info.doc.map(|it| it.into()), Some("test".to_string()));
     }
 
     #[test]
@@ -313,18 +283,18 @@ pub fn do() {
         assert_eq!(info.active_parameter, Some(0));
         assert_eq!(info.label, "pub fn add_one(x: i32) -> i32".to_string());
         assert_eq!(
-            info.doc,
+            info.doc.map(|it| it.into()),
             Some(
                 r#"Adds one to the number given.
 
 # Examples
 
-```rust
+```
 let five = 5;
 
 assert_eq!(6, my_crate::add_one(5));
 ```"#
-                    .into()
+                    .to_string()
             )
         );
     }
@@ -359,18 +329,18 @@ pub fn do_it() {
         assert_eq!(info.active_parameter, Some(0));
         assert_eq!(info.label, "pub fn add_one(x: i32) -> i32".to_string());
         assert_eq!(
-            info.doc,
+            info.doc.map(|it| it.into()),
             Some(
                 r#"Adds one to the number given.
 
 # Examples
 
-```rust
+```
 let five = 5;
 
 assert_eq!(6, my_crate::add_one(5));
 ```"#
-                    .into()
+                    .to_string()
             )
         );
     }
@@ -414,12 +384,12 @@ pub fn foo() {
         );
         assert_eq!(info.active_parameter, Some(1));
         assert_eq!(
-            info.doc,
+            info.doc.map(|it| it.into()),
             Some(
                 r#"Method is called when writer finishes.
 
 By default this method stops actor's `Context`."#
-                    .into()
+                    .to_string()
             )
         );
     }
diff --git a/crates/ra_ide_api/src/completion.rs b/crates/ra_ide_api/src/completion.rs
index b1867de42..722d94f3a 100644
--- a/crates/ra_ide_api/src/completion.rs
+++ b/crates/ra_ide_api/src/completion.rs
@@ -10,6 +10,7 @@ mod complete_scope;
 mod complete_postfix;
 
 use ra_db::SourceDatabase;
+use ra_syntax::ast::{self, AstNode};
 
 use crate::{
     db,
@@ -61,3 +62,21 @@ pub(crate) fn completions(db: &db::RootDatabase, position: FilePosition) -> Opti
     complete_postfix::complete_postfix(&mut acc, &ctx);
     Some(acc)
 }
+
+pub fn function_label(node: &ast::FnDef) -> Option<String> {
+    let label: String = if let Some(body) = node.body() {
+        let body_range = body.syntax().range();
+        let label: String = node
+            .syntax()
+            .children()
+            .filter(|child| !child.range().is_subrange(&body_range)) // Filter out body
+            .filter(|child| ast::Comment::cast(child).is_none()) // Filter out comments
+            .map(|node| node.text().to_string())
+            .collect();
+        label
+    } else {
+        node.syntax().text().to_string()
+    };
+
+    Some(label.trim().to_owned())
+}
diff --git a/crates/ra_ide_api/src/completion/completion_item.rs b/crates/ra_ide_api/src/completion/completion_item.rs
index b16ac2b28..d3bc14894 100644
--- a/crates/ra_ide_api/src/completion/completion_item.rs
+++ b/crates/ra_ide_api/src/completion/completion_item.rs
@@ -1,12 +1,12 @@
 use hir::{Docs, Documentation};
-use ra_syntax::{
-    ast::{self, AstNode},
-    TextRange,
-};
+use ra_syntax::TextRange;
 use ra_text_edit::TextEdit;
 use test_utils::tested_by;
 
-use crate::completion::completion_context::CompletionContext;
+use crate::completion::{
+    completion_context::CompletionContext,
+    function_label,
+};
 
 /// `CompletionItem` describes a single completion variant in the editor pop-up.
 /// It is basically a POD with various properties. To construct a
@@ -97,8 +97,8 @@ impl CompletionItem {
         self.detail.as_ref().map(|it| it.as_str())
     }
     /// A doc-comment
-    pub fn documentation(&self) -> Option<&str> {
-        self.documentation.as_ref().map(|it| it.contents())
+    pub fn documentation(&self) -> Option<Documentation> {
+        self.documentation.clone()
     }
     /// What string is used for filtering.
     pub fn lookup(&self) -> &str {
@@ -252,7 +252,7 @@ impl Builder {
             self.documentation = Some(docs);
         }
 
-        if let Some(label) = function_label(ctx, function) {
+        if let Some(label) = function_item_label(ctx, function) {
             self.detail = Some(label);
         }
 
@@ -292,24 +292,9 @@ impl Into<Vec<CompletionItem>> for Completions {
     }
 }
 
-fn function_label(ctx: &CompletionContext, function: hir::Function) -> Option<String> {
+fn function_item_label(ctx: &CompletionContext, function: hir::Function) -> Option<String> {
     let node = function.source(ctx.db).1;
-
-    let label: String = if let Some(body) = node.body() {
-        let body_range = body.syntax().range();
-        let label: String = node
-            .syntax()
-            .children()
-            .filter(|child| !child.range().is_subrange(&body_range)) // Filter out body
-            .filter(|child| ast::Comment::cast(child).is_none()) // Filter out comments
-            .map(|node| node.text().to_string())
-            .collect();
-        label
-    } else {
-        node.syntax().text().to_string()
-    };
-
-    Some(label.trim().to_owned())
+    function_label(&node)
 }
 
 #[cfg(test)]
@@ -324,10 +309,11 @@ pub(crate) fn check_completion(test_name: &str, code: &str, kind: CompletionKind
     };
     let completions = completions(&analysis.db, position).unwrap();
     let completion_items: Vec<CompletionItem> = completions.into();
-    let kind_completions: Vec<CompletionItem> = completion_items
+    let mut kind_completions: Vec<CompletionItem> = completion_items
         .into_iter()
         .filter(|c| c.completion_kind == kind)
         .collect();
+    kind_completions.sort_by_key(|c| c.label.clone());
     assert_debug_snapshot_matches!(test_name, kind_completions);
 }
 
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__bindings_from_for.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__bindings_from_for.snap
index 329309c90..31df6565b 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__bindings_from_for.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__bindings_from_for.snap
@@ -1,26 +1,12 @@
 ---
-created: "2019-01-23T07:42:59.656273+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.944446814+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Reference,
-        label: "x",
-        kind: Some(
-            Binding
-        ),
-        detail: None,
-        documentation: None,
-        lookup: None,
-        insert_text: None,
-        insert_text_format: PlainText,
-        source_range: [83; 83),
-        text_edit: None
-    },
-    CompletionItem {
-        completion_kind: Reference,
         label: "quux",
         kind: Some(
             Function
@@ -36,5 +22,19 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         insert_text_format: Snippet,
         source_range: [83; 83),
         text_edit: None
+    },
+    CompletionItem {
+        completion_kind: Reference,
+        label: "x",
+        kind: Some(
+            Binding
+        ),
+        detail: None,
+        documentation: None,
+        lookup: None,
+        insert_text: None,
+        insert_text_format: PlainText,
+        source_range: [83; 83),
+        text_edit: None
     }
 ]
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__bindings_from_if_let.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__bindings_from_if_let.snap
index dbbe06c7b..9f37bae36 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__bindings_from_if_let.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__bindings_from_if_let.snap
@@ -1,13 +1,13 @@
 ---
-created: "2019-01-23T07:42:59.658419+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.946956414+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Reference,
-        label: "b",
+        label: "a",
         kind: Some(
             Binding
         ),
@@ -21,7 +21,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Reference,
-        label: "a",
+        label: "b",
         kind: Some(
             Binding
         ),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__bindings_from_let.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__bindings_from_let.snap
index b727bb70c..f4808bc93 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__bindings_from_let.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__bindings_from_let.snap
@@ -1,21 +1,25 @@
 ---
-created: "2019-01-23T07:42:59.657713+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.948953759+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Reference,
-        label: "y",
+        label: "quux",
         kind: Some(
-            Binding
+            Function
+        ),
+        detail: Some(
+            "fn quux(x: i32)"
         ),
-        detail: None,
         documentation: None,
         lookup: None,
-        insert_text: None,
-        insert_text_format: PlainText,
+        insert_text: Some(
+            "quux($0)"
+        ),
+        insert_text_format: Snippet,
         source_range: [79; 79),
         text_edit: None
     },
@@ -35,19 +39,15 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Reference,
-        label: "quux",
+        label: "y",
         kind: Some(
-            Function
-        ),
-        detail: Some(
-            "fn quux(x: i32)"
+            Binding
         ),
+        detail: None,
         documentation: None,
         lookup: None,
-        insert_text: Some(
-            "quux($0)"
-        ),
-        insert_text_format: Snippet,
+        insert_text: None,
+        insert_text_format: PlainText,
         source_range: [79; 79),
         text_edit: None
     }
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__completes_break_and_continue_in_loops1.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__completes_break_and_continue_in_loops1.snap
index 8dcb773d0..25ccbdb8f 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__completes_break_and_continue_in_loops1.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__completes_break_and_continue_in_loops1.snap
@@ -1,13 +1,13 @@
 ---
-created: "2019-01-23T05:27:32.197434+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.913816522+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Keyword,
-        label: "if",
+        label: "break",
         kind: Some(
             Keyword
         ),
@@ -15,7 +15,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "if $0 {}"
+            "break;"
         ),
         insert_text_format: Snippet,
         source_range: [55; 55),
@@ -23,7 +23,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "match",
+        label: "continue",
         kind: Some(
             Keyword
         ),
@@ -31,7 +31,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match $0 {}"
+            "continue;"
         ),
         insert_text_format: Snippet,
         source_range: [55; 55),
@@ -39,7 +39,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "while",
+        label: "if",
         kind: Some(
             Keyword
         ),
@@ -47,7 +47,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "while $0 {}"
+            "if $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [55; 55),
@@ -71,7 +71,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "continue",
+        label: "match",
         kind: Some(
             Keyword
         ),
@@ -79,7 +79,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "continue;"
+            "match $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [55; 55),
@@ -87,7 +87,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "break",
+        label: "return",
         kind: Some(
             Keyword
         ),
@@ -95,7 +95,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "break;"
+            "return $0;"
         ),
         insert_text_format: Snippet,
         source_range: [55; 55),
@@ -103,7 +103,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "return",
+        label: "while",
         kind: Some(
             Keyword
         ),
@@ -111,7 +111,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "return $0;"
+            "while $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [55; 55),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__completes_break_and_continue_in_loops2.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__completes_break_and_continue_in_loops2.snap
index 1c64c6548..42a888e3a 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__completes_break_and_continue_in_loops2.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__completes_break_and_continue_in_loops2.snap
@@ -1,6 +1,6 @@
 ---
-created: "2019-01-23T05:27:32.314513+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T20:00:15.602646258+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
@@ -23,7 +23,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "match",
+        label: "loop",
         kind: Some(
             Keyword
         ),
@@ -31,7 +31,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match $0 {}"
+            "loop {$0}"
         ),
         insert_text_format: Snippet,
         source_range: [60; 60),
@@ -39,7 +39,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "while",
+        label: "match",
         kind: Some(
             Keyword
         ),
@@ -47,7 +47,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "while $0 {}"
+            "match $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [60; 60),
@@ -55,7 +55,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "loop",
+        label: "return",
         kind: Some(
             Keyword
         ),
@@ -63,7 +63,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "loop {$0}"
+            "return $0;"
         ),
         insert_text_format: Snippet,
         source_range: [60; 60),
@@ -71,7 +71,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "return",
+        label: "while",
         kind: Some(
             Keyword
         ),
@@ -79,7 +79,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "return $0;"
+            "while $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [60; 60),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__dont_add_semi_after_return_if_not_a_statement.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__dont_add_semi_after_return_if_not_a_statement.snap
index 8c9657b5c..5e4ff6af8 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__dont_add_semi_after_return_if_not_a_statement.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__dont_add_semi_after_return_if_not_a_statement.snap
@@ -1,6 +1,6 @@
 ---
-created: "2019-01-23T05:27:32.197678+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.920190685+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
@@ -23,7 +23,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "match",
+        label: "loop",
         kind: Some(
             Keyword
         ),
@@ -31,7 +31,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match $0 {}"
+            "loop {$0}"
         ),
         insert_text_format: Snippet,
         source_range: [85; 85),
@@ -39,7 +39,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "while",
+        label: "match",
         kind: Some(
             Keyword
         ),
@@ -47,7 +47,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "while $0 {}"
+            "match $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [85; 85),
@@ -55,7 +55,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "loop",
+        label: "return",
         kind: Some(
             Keyword
         ),
@@ -63,7 +63,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "loop {$0}"
+            "return $0"
         ),
         insert_text_format: Snippet,
         source_range: [85; 85),
@@ -71,7 +71,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "return",
+        label: "while",
         kind: Some(
             Keyword
         ),
@@ -79,7 +79,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "return $0"
+            "while $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [85; 85),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__dont_render_function_parens_if_already_call.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__dont_render_function_parens_if_already_call.snap
index 091bf581e..f4a04ecb3 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__dont_render_function_parens_if_already_call.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__dont_render_function_parens_if_already_call.snap
@@ -1,18 +1,18 @@
 ---
-created: "2019-01-22T15:38:19.788294+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.965130040+00:00"
+creator: insta@0.5.2
 expression: kind_completions
-source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
+source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Reference,
-        label: "main",
+        label: "frobnicate",
         kind: Some(
             Function
         ),
         detail: Some(
-            "fn main()"
+            "fn frobnicate()"
         ),
         documentation: None,
         lookup: None,
@@ -23,12 +23,12 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
     },
     CompletionItem {
         completion_kind: Reference,
-        label: "frobnicate",
+        label: "main",
         kind: Some(
             Function
         ),
         detail: Some(
-            "fn frobnicate()"
+            "fn main()"
         ),
         documentation: None,
         lookup: None,
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__enum_variant.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__enum_variant.snap
index 8c84439b2..8ac58006e 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__enum_variant.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__enum_variant.snap
@@ -1,5 +1,5 @@
 ---
-created: "2019-01-25T16:44:04.640545300+00:00"
+created: "2019-01-27T19:56:59.937030324+00:00"
 creator: [email protected]
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
@@ -7,16 +7,16 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
 [
     CompletionItem {
         completion_kind: Reference,
-        label: "Foo",
+        label: "Bar",
         kind: Some(
             EnumVariant
         ),
         detail: Some(
-            "()"
+            "(i32)"
         ),
         documentation: Some(
             Documentation(
-                "Foo Variant"
+                "Bar Variant with i32"
             )
         ),
         lookup: None,
@@ -27,16 +27,16 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Reference,
-        label: "Bar",
+        label: "Foo",
         kind: Some(
             EnumVariant
         ),
         detail: Some(
-            "(i32)"
+            "()"
         ),
         documentation: Some(
             Documentation(
-                "Bar Variant with i32"
+                "Foo Variant"
             )
         ),
         lookup: None,
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__enum_variant_with_details.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__enum_variant_with_details.snap
index 384634517..9fd2d81ec 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__enum_variant_with_details.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__enum_variant_with_details.snap
@@ -1,5 +1,5 @@
 ---
-created: "2019-01-25T16:44:04.641542400+00:00"
+created: "2019-01-27T19:56:59.938973454+00:00"
 creator: [email protected]
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
@@ -7,16 +7,16 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
 [
     CompletionItem {
         completion_kind: Reference,
-        label: "Foo",
+        label: "Bar",
         kind: Some(
             EnumVariant
         ),
         detail: Some(
-            "()"
+            "(i32, u32)"
         ),
         documentation: Some(
             Documentation(
-                "Foo Variant (empty)"
+                "Bar Variant with i32 and u32"
             )
         ),
         lookup: None,
@@ -27,16 +27,16 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Reference,
-        label: "Bar",
+        label: "Foo",
         kind: Some(
             EnumVariant
         ),
         detail: Some(
-            "(i32, u32)"
+            "()"
         ),
         documentation: Some(
             Documentation(
-                "Bar Variant with i32 and u32"
+                "Foo Variant (empty)"
             )
         ),
         lookup: None,
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__filter_postfix_completion1.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__filter_postfix_completion1.snap
index 13f915446..6b2287951 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__filter_postfix_completion1.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__filter_postfix_completion1.snap
@@ -1,19 +1,19 @@
 ---
-created: "2019-01-22T14:45:00.817649800+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.944118550+00:00"
+creator: insta@0.5.2
 expression: kind_completions
-source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
+source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Postfix,
-        label: "not",
+        label: "if",
         kind: None,
         detail: None,
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "!bar"
+            "if bar {$0}"
         ),
         insert_text_format: Snippet,
         source_range: [76; 76),
@@ -30,13 +30,13 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
     },
     CompletionItem {
         completion_kind: Postfix,
-        label: "if",
+        label: "match",
         kind: None,
         detail: None,
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "if bar {$0}"
+            "match bar {\n${1:_} => {$0\\},\n}"
         ),
         insert_text_format: Snippet,
         source_range: [76; 76),
@@ -53,13 +53,13 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
     },
     CompletionItem {
         completion_kind: Postfix,
-        label: "match",
+        label: "not",
         kind: None,
         detail: None,
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match bar {\n${1:_} => {$0\\},\n}"
+            "!bar"
         ),
         insert_text_format: Snippet,
         source_range: [76; 76),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__filter_postfix_completion2.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__filter_postfix_completion2.snap
index fff87574d..6925fd102 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__filter_postfix_completion2.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__filter_postfix_completion2.snap
@@ -1,19 +1,19 @@
 ---
-created: "2019-01-22T14:45:00.820642200+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.942831213+00:00"
+creator: insta@0.5.2
 expression: kind_completions
-source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
+source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Postfix,
-        label: "not",
+        label: "if",
         kind: None,
         detail: None,
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "!bar"
+            "if bar {$0}"
         ),
         insert_text_format: Snippet,
         source_range: [76; 77),
@@ -30,13 +30,13 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
     },
     CompletionItem {
         completion_kind: Postfix,
-        label: "if",
+        label: "match",
         kind: None,
         detail: None,
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "if bar {$0}"
+            "match bar {\n${1:_} => {$0\\},\n}"
         ),
         insert_text_format: Snippet,
         source_range: [76; 77),
@@ -53,13 +53,13 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
     },
     CompletionItem {
         completion_kind: Postfix,
-        label: "match",
+        label: "not",
         kind: None,
         detail: None,
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match bar {\n${1:_} => {$0\\},\n}"
+            "!bar"
         ),
         insert_text_format: Snippet,
         source_range: [76; 77),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__filter_postfix_completion3.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__filter_postfix_completion3.snap
index e0f4730e7..22eaf2b4f 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__filter_postfix_completion3.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__filter_postfix_completion3.snap
@@ -1,19 +1,19 @@
 ---
-created: "2019-01-23T05:27:32.222118+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.944615925+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Postfix,
-        label: "not",
+        label: "if",
         kind: None,
         detail: None,
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "!bar"
+            "if bar {$0}"
         ),
         insert_text_format: Snippet,
         source_range: [78; 78),
@@ -30,13 +30,13 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Postfix,
-        label: "if",
+        label: "match",
         kind: None,
         detail: None,
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "if bar {$0}"
+            "match bar {\n${1:_} => {$0\\},\n}"
         ),
         insert_text_format: Snippet,
         source_range: [78; 78),
@@ -53,13 +53,13 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Postfix,
-        label: "match",
+        label: "not",
         kind: None,
         detail: None,
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match bar {\n${1:_} => {$0\\},\n}"
+            "!bar"
         ),
         insert_text_format: Snippet,
         source_range: [78; 78),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__inserts_parens_for_function_calls1.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__inserts_parens_for_function_calls1.snap
index b30a4c9e9..339df3c84 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__inserts_parens_for_function_calls1.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__inserts_parens_for_function_calls1.snap
@@ -1,23 +1,23 @@
 ---
-created: "2019-01-22T15:38:19.919937+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.965550827+00:00"
+creator: insta@0.5.2
 expression: kind_completions
-source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
+source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Reference,
-        label: "no_args",
+        label: "main",
         kind: Some(
             Function
         ),
         detail: Some(
-            "fn no_args()"
+            "fn main()"
         ),
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "no_args()$0"
+            "main()$0"
         ),
         insert_text_format: Snippet,
         source_range: [53; 56),
@@ -25,17 +25,17 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
     },
     CompletionItem {
         completion_kind: Reference,
-        label: "main",
+        label: "no_args",
         kind: Some(
             Function
         ),
         detail: Some(
-            "fn main()"
+            "fn no_args()"
         ),
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "main()$0"
+            "no_args()$0"
         ),
         insert_text_format: Snippet,
         source_range: [53; 56),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function1.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function1.snap
index 2b6182578..874c41a02 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function1.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function1.snap
@@ -1,6 +1,6 @@
 ---
-created: "2019-01-23T05:27:32.197298+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.913826978+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
@@ -23,7 +23,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "match",
+        label: "loop",
         kind: Some(
             Keyword
         ),
@@ -31,7 +31,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match $0 {}"
+            "loop {$0}"
         ),
         insert_text_format: Snippet,
         source_range: [41; 41),
@@ -39,7 +39,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "while",
+        label: "match",
         kind: Some(
             Keyword
         ),
@@ -47,7 +47,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "while $0 {}"
+            "match $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [41; 41),
@@ -55,7 +55,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "loop",
+        label: "return",
         kind: Some(
             Keyword
         ),
@@ -63,7 +63,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "loop {$0}"
+            "return;"
         ),
         insert_text_format: Snippet,
         source_range: [41; 41),
@@ -71,7 +71,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "return",
+        label: "while",
         kind: Some(
             Keyword
         ),
@@ -79,7 +79,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "return;"
+            "while $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [41; 41),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function2.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function2.snap
index a56105f0c..0eec578be 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function2.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function2.snap
@@ -1,13 +1,13 @@
 ---
-created: "2019-01-23T05:27:32.197423+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.914744437+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Keyword,
-        label: "if",
+        label: "else",
         kind: Some(
             Keyword
         ),
@@ -15,7 +15,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "if $0 {}"
+            "else {$0}"
         ),
         insert_text_format: Snippet,
         source_range: [92; 92),
@@ -23,7 +23,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "match",
+        label: "else if",
         kind: Some(
             Keyword
         ),
@@ -31,7 +31,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match $0 {}"
+            "else if $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [92; 92),
@@ -39,7 +39,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "while",
+        label: "if",
         kind: Some(
             Keyword
         ),
@@ -47,7 +47,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "while $0 {}"
+            "if $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [92; 92),
@@ -71,7 +71,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "else",
+        label: "match",
         kind: Some(
             Keyword
         ),
@@ -79,7 +79,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "else {$0}"
+            "match $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [92; 92),
@@ -87,7 +87,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "else if",
+        label: "return",
         kind: Some(
             Keyword
         ),
@@ -95,7 +95,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "else if $0 {}"
+            "return;"
         ),
         insert_text_format: Snippet,
         source_range: [92; 92),
@@ -103,7 +103,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "return",
+        label: "while",
         kind: Some(
             Keyword
         ),
@@ -111,7 +111,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "return;"
+            "while $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [92; 92),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function3.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function3.snap
index 84efab6f6..4b99f15e1 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function3.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function3.snap
@@ -1,6 +1,6 @@
 ---
-created: "2019-01-23T05:27:32.200056+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.927994050+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
@@ -23,7 +23,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "match",
+        label: "loop",
         kind: Some(
             Keyword
         ),
@@ -31,7 +31,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match $0 {}"
+            "loop {$0}"
         ),
         insert_text_format: Snippet,
         source_range: [48; 48),
@@ -39,7 +39,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "while",
+        label: "match",
         kind: Some(
             Keyword
         ),
@@ -47,7 +47,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "while $0 {}"
+            "match $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [48; 48),
@@ -55,7 +55,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "loop",
+        label: "return",
         kind: Some(
             Keyword
         ),
@@ -63,7 +63,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "loop {$0}"
+            "return $0;"
         ),
         insert_text_format: Snippet,
         source_range: [48; 48),
@@ -71,7 +71,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "return",
+        label: "while",
         kind: Some(
             Keyword
         ),
@@ -79,7 +79,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "return $0;"
+            "while $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [48; 48),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function4.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function4.snap
index 8b254ce99..f8587f147 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function4.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__keywords_in_function4.snap
@@ -1,6 +1,6 @@
 ---
-created: "2019-01-23T05:27:32.314468+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T20:00:15.604538211+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
@@ -23,7 +23,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "match",
+        label: "loop",
         kind: Some(
             Keyword
         ),
@@ -31,7 +31,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match $0 {}"
+            "loop {$0}"
         ),
         insert_text_format: Snippet,
         source_range: [41; 41),
@@ -39,7 +39,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "while",
+        label: "match",
         kind: Some(
             Keyword
         ),
@@ -47,7 +47,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "while $0 {}"
+            "match $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [41; 41),
@@ -55,7 +55,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "loop",
+        label: "return",
         kind: Some(
             Keyword
         ),
@@ -63,7 +63,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "loop {$0}"
+            "return;"
         ),
         insert_text_format: Snippet,
         source_range: [41; 41),
@@ -71,7 +71,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "return",
+        label: "while",
         kind: Some(
             Keyword
         ),
@@ -79,7 +79,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "return;"
+            "while $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [41; 41),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__last_return_in_block_has_semi1.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__last_return_in_block_has_semi1.snap
index d36b555db..3c27e079f 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__last_return_in_block_has_semi1.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__last_return_in_block_has_semi1.snap
@@ -1,6 +1,6 @@
 ---
-created: "2019-01-23T05:27:32.197624+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.918882346+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
@@ -23,7 +23,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "match",
+        label: "loop",
         kind: Some(
             Keyword
         ),
@@ -31,7 +31,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match $0 {}"
+            "loop {$0}"
         ),
         insert_text_format: Snippet,
         source_range: [83; 83),
@@ -39,7 +39,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "while",
+        label: "match",
         kind: Some(
             Keyword
         ),
@@ -47,7 +47,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "while $0 {}"
+            "match $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [83; 83),
@@ -55,7 +55,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "loop",
+        label: "return",
         kind: Some(
             Keyword
         ),
@@ -63,7 +63,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "loop {$0}"
+            "return $0;"
         ),
         insert_text_format: Snippet,
         source_range: [83; 83),
@@ -71,7 +71,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "return",
+        label: "while",
         kind: Some(
             Keyword
         ),
@@ -79,7 +79,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "return $0;"
+            "while $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [83; 83),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__last_return_in_block_has_semi2.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__last_return_in_block_has_semi2.snap
index d74483c0b..d1be8c6e7 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__last_return_in_block_has_semi2.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__last_return_in_block_has_semi2.snap
@@ -1,6 +1,6 @@
 ---
-created: "2019-01-23T05:27:32.302452+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T20:00:15.604282112+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
@@ -23,7 +23,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "match",
+        label: "loop",
         kind: Some(
             Keyword
         ),
@@ -31,7 +31,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match $0 {}"
+            "loop {$0}"
         ),
         insert_text_format: Snippet,
         source_range: [83; 83),
@@ -39,7 +39,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "while",
+        label: "match",
         kind: Some(
             Keyword
         ),
@@ -47,7 +47,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "while $0 {}"
+            "match $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [83; 83),
@@ -55,7 +55,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "loop",
+        label: "return",
         kind: Some(
             Keyword
         ),
@@ -63,7 +63,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "loop {$0}"
+            "return $0;"
         ),
         insert_text_format: Snippet,
         source_range: [83; 83),
@@ -71,7 +71,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "return",
+        label: "while",
         kind: Some(
             Keyword
         ),
@@ -79,7 +79,7 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "return $0;"
+            "while $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [83; 83),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__module_items.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__module_items.snap
index a87880ab3..f6bba49ae 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__module_items.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__module_items.snap
@@ -1,25 +1,21 @@
 ---
-created: "2019-01-23T07:42:59.657718+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.953151082+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Reference,
-        label: "quux",
+        label: "Baz",
         kind: Some(
-            Function
-        ),
-        detail: Some(
-            "fn quux()"
+            Enum
         ),
+        detail: None,
         documentation: None,
         lookup: None,
-        insert_text: Some(
-            "quux()$0"
-        ),
-        insert_text_format: Snippet,
+        insert_text: None,
+        insert_text_format: PlainText,
         source_range: [89; 89),
         text_edit: None
     },
@@ -39,15 +35,19 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
     },
     CompletionItem {
         completion_kind: Reference,
-        label: "Baz",
+        label: "quux",
         kind: Some(
-            Enum
+            Function
+        ),
+        detail: Some(
+            "fn quux()"
         ),
-        detail: None,
         documentation: None,
         lookup: None,
-        insert_text: None,
-        insert_text_format: PlainText,
+        insert_text: Some(
+            "quux()$0"
+        ),
+        insert_text_format: Snippet,
         source_range: [89; 89),
         text_edit: None
     }
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__module_items_in_nested_modules.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__module_items_in_nested_modules.snap
index f95d10926..7c458664e 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__module_items_in_nested_modules.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__module_items_in_nested_modules.snap
@@ -1,39 +1,39 @@
 ---
-created: "2019-01-23T07:42:59.657837+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.959185284+00:00"
+creator: insta@0.5.2
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Reference,
-        label: "quux",
+        label: "Bar",
         kind: Some(
-            Function
-        ),
-        detail: Some(
-            "fn quux()"
+            Struct
         ),
+        detail: None,
         documentation: None,
         lookup: None,
-        insert_text: Some(
-            "quux()$0"
-        ),
-        insert_text_format: Snippet,
+        insert_text: None,
+        insert_text_format: PlainText,
         source_range: [101; 101),
         text_edit: None
     },
     CompletionItem {
         completion_kind: Reference,
-        label: "Bar",
+        label: "quux",
         kind: Some(
-            Struct
+            Function
+        ),
+        detail: Some(
+            "fn quux()"
         ),
-        detail: None,
         documentation: None,
         lookup: None,
-        insert_text: None,
-        insert_text_format: PlainText,
+        insert_text: Some(
+            "quux()$0"
+        ),
+        insert_text_format: Snippet,
         source_range: [101; 101),
         text_edit: None
     }
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__no_semi_after_break_continue_in_expr.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__no_semi_after_break_continue_in_expr.snap
index a5164b03e..5a35d9ca9 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__no_semi_after_break_continue_in_expr.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__no_semi_after_break_continue_in_expr.snap
@@ -1,13 +1,13 @@
 ---
-created: "2019-01-22T14:45:00.651095300+00:00"
-creator: insta@0.4.0
+created: "2019-01-27T19:56:59.922933445+00:00"
+creator: insta@0.5.2
 expression: kind_completions
-source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
+source: crates/ra_ide_api/src/completion/completion_item.rs
 ---
 [
     CompletionItem {
         completion_kind: Keyword,
-        label: "if",
+        label: "break",
         kind: Some(
             Keyword
         ),
@@ -15,7 +15,7 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "if $0 {}"
+            "break"
         ),
         insert_text_format: Snippet,
         source_range: [106; 108),
@@ -23,7 +23,7 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "match",
+        label: "continue",
         kind: Some(
             Keyword
         ),
@@ -31,7 +31,7 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "match $0 {}"
+            "continue"
         ),
         insert_text_format: Snippet,
         source_range: [106; 108),
@@ -39,7 +39,7 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "while",
+        label: "if",
         kind: Some(
             Keyword
         ),
@@ -47,7 +47,7 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "while $0 {}"
+            "if $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [106; 108),
@@ -71,7 +71,7 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "continue",
+        label: "match",
         kind: Some(
             Keyword
         ),
@@ -79,7 +79,7 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "continue"
+            "match $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [106; 108),
@@ -87,7 +87,7 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "break",
+        label: "return",
         kind: Some(
             Keyword
         ),
@@ -95,7 +95,7 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "break"
+            "return"
         ),
         insert_text_format: Snippet,
         source_range: [106; 108),
@@ -103,7 +103,7 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
     },
     CompletionItem {
         completion_kind: Keyword,
-        label: "return",
+        label: "while",
         kind: Some(
             Keyword
         ),
@@ -111,7 +111,7 @@ source: "crates\\ra_ide_api\\src\\completion\\completion_item.rs"
         documentation: None,
         lookup: None,
         insert_text: Some(
-            "return"
+            "while $0 {}"
         ),
         insert_text_format: Snippet,
         source_range: [106; 108),
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__struct_field_completion_autoderef.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__struct_field_completion_autoderef.snap
index 5f5df0033..4d5c7a869 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__struct_field_completion_autoderef.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__struct_field_completion_autoderef.snap
@@ -1,5 +1,5 @@
 ---
-created: "2019-01-23T13:19:23.501353210+00:00"
+created: "2019-01-27T19:56:59.910113268+00:00"
 creator: [email protected]
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
@@ -7,35 +7,35 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
 [
     CompletionItem {
         completion_kind: Reference,
-        label: "the_field",
+        label: "foo",
         kind: Some(
-            Field
+            Method
         ),
         detail: Some(
-            "(u32, i32)"
+            "fn foo(&self)"
         ),
         documentation: None,
         lookup: None,
-        insert_text: None,
-        insert_text_format: PlainText,
+        insert_text: Some(
+            "foo()$0"
+        ),
+        insert_text_format: Snippet,
         source_range: [126; 126),
         text_edit: None
     },
     CompletionItem {
         completion_kind: Reference,
-        label: "foo",
+        label: "the_field",
         kind: Some(
-            Method
+            Field
         ),
         detail: Some(
-            "fn foo(&self)"
+            "(u32, i32)"
         ),
         documentation: None,
         lookup: None,
-        insert_text: Some(
-            "foo()$0"
-        ),
-        insert_text_format: Snippet,
+        insert_text: None,
+        insert_text_format: PlainText,
         source_range: [126; 126),
         text_edit: None
     }
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__struct_field_completion_self.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__struct_field_completion_self.snap
index 580e92a90..1073d90fd 100644
--- a/crates/ra_ide_api/src/completion/snapshots/completion_item__struct_field_completion_self.snap
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__struct_field_completion_self.snap
@@ -1,5 +1,5 @@
 ---
-created: "2019-01-25T19:27:09.519688600+00:00"
+created: "2019-01-27T19:56:59.909689544+00:00"
 creator: [email protected]
 expression: kind_completions
 source: crates/ra_ide_api/src/completion/completion_item.rs
@@ -7,39 +7,39 @@ source: crates/ra_ide_api/src/completion/completion_item.rs
 [
     CompletionItem {
         completion_kind: Reference,
-        label: "the_field",
+        label: "foo",
         kind: Some(
-            Field
+            Method
         ),
         detail: Some(
-            "(u32,)"
-        ),
-        documentation: Some(
-            Documentation(
-                "This is the_field"
-            )
+            "fn foo(self)"
         ),
+        documentation: None,
         lookup: None,
-        insert_text: None,
-        insert_text_format: PlainText,
+        insert_text: Some(
+            "foo()$0"
+        ),
+        insert_text_format: Snippet,
         source_range: [187; 187),
         text_edit: None
     },
     CompletionItem {
         completion_kind: Reference,
-        label: "foo",
+        label: "the_field",
         kind: Some(
-            Method
+            Field
         ),
         detail: Some(
-            "fn foo(self)"
+            "(u32,)"
         ),
-        documentation: None,
-        lookup: None,
-        insert_text: Some(
-            "foo()$0"
+        documentation: Some(
+            Documentation(
+                "This is the_field"
+            )
         ),
-        insert_text_format: Snippet,
+        lookup: None,
+        insert_text: None,
+        insert_text_format: PlainText,
         source_range: [187; 187),
         text_edit: None
     }
diff --git a/crates/ra_ide_api/src/db.rs b/crates/ra_ide_api/src/db.rs
index 3da93ec35..6850811d7 100644
--- a/crates/ra_ide_api/src/db.rs
+++ b/crates/ra_ide_api/src/db.rs
@@ -1,4 +1,7 @@
-use std::sync::Arc;
+use std::{
+    sync::Arc,
+    time,
+};
 
 use ra_db::{
     CheckCanceled, FileId, Canceled, SourceDatabase,
@@ -17,6 +20,8 @@ use crate::{LineIndex, symbol_index::{self, SymbolsDatabase}};
 pub(crate) struct RootDatabase {
     runtime: salsa::Runtime<RootDatabase>,
     interner: Arc<hir::HirInterner>,
+    pub(crate) last_gc: time::Instant,
+    pub(crate) last_gc_check: time::Instant,
 }
 
 impl salsa::Database for RootDatabase {
@@ -33,6 +38,8 @@ impl Default for RootDatabase {
         let mut db = RootDatabase {
             runtime: salsa::Runtime::default(),
             interner: Default::default(),
+            last_gc: time::Instant::now(),
+            last_gc_check: time::Instant::now(),
         };
         db.set_crate_graph(Default::default());
         db.set_local_roots(Default::default());
@@ -46,6 +53,8 @@ impl salsa::ParallelDatabase for RootDatabase {
         salsa::Snapshot::new(RootDatabase {
             runtime: self.runtime.snapshot(self),
             interner: Arc::clone(&self.interner),
+            last_gc: self.last_gc.clone(),
+            last_gc_check: self.last_gc_check.clone(),
         })
     }
 }
diff --git a/crates/ra_ide_api/src/imp.rs b/crates/ra_ide_api/src/imp.rs
index 399433a01..31e0f5d6d 100644
--- a/crates/ra_ide_api/src/imp.rs
+++ b/crates/ra_ide_api/src/imp.rs
@@ -1,4 +1,7 @@
-use std::sync::Arc;
+use std::{
+    sync::Arc,
+    time,
+};
 
 use hir::{
     self, Problem, source_binder
@@ -19,12 +22,14 @@ use crate::{
     CrateId, db, Diagnostic, FileId, FilePosition, FileRange, FileSystemEdit,
     Query, RootChange, SourceChange, SourceFileEdit,
     symbol_index::{FileSymbol, SymbolsDatabase},
+    status::syntax_tree_stats
 };
 
+const GC_COOLDOWN: time::Duration = time::Duration::from_millis(100);
+
 impl db::RootDatabase {
     pub(crate) fn apply_change(&mut self, change: AnalysisChange) {
         log::info!("apply_change {:?}", change);
-        // self.gc_syntax_trees();
         if !change.new_roots.is_empty() {
             let mut local_roots = Vec::clone(&self.local_roots());
             for (root_id, is_local) in change.new_roots {
@@ -72,18 +77,36 @@ impl db::RootDatabase {
         self.set_source_root(root_id, Arc::new(source_root));
     }
 
-    /// Ideally, we should call this function from time to time to collect heavy
-    /// syntax trees. However, if we actually do that, everything is recomputed
-    /// for some reason. Needs investigation.
+    pub(crate) fn maybe_collect_garbage(&mut self) {
+        if self.last_gc_check.elapsed() > GC_COOLDOWN {
+            self.last_gc_check = time::Instant::now();
+            let retained_trees = syntax_tree_stats(self).retained;
+            if retained_trees > 100 {
+                log::info!(
+                    "automatic garbadge collection, {} retained trees",
+                    retained_trees
+                );
+                self.collect_garbage();
+            }
+        }
+    }
+
     pub(crate) fn collect_garbage(&mut self) {
-        self.query(ra_db::ParseQuery)
-            .sweep(SweepStrategy::default().discard_values());
-        self.query(hir::db::HirParseQuery)
-            .sweep(SweepStrategy::default().discard_values());
-        self.query(hir::db::FileItemsQuery)
-            .sweep(SweepStrategy::default().discard_values());
-        self.query(hir::db::FileItemQuery)
-            .sweep(SweepStrategy::default().discard_values());
+        self.last_gc = time::Instant::now();
+
+        let sweep = SweepStrategy::default()
+            .discard_values()
+            .sweep_all_revisions();
+
+        self.query(ra_db::ParseQuery).sweep(sweep);
+
+        self.query(hir::db::HirParseQuery).sweep(sweep);
+        self.query(hir::db::FileItemsQuery).sweep(sweep);
+        self.query(hir::db::FileItemQuery).sweep(sweep);
+
+        self.query(hir::db::LowerModuleQuery).sweep(sweep);
+        self.query(hir::db::LowerModuleSourceMapQuery).sweep(sweep);
+        self.query(hir::db::BodySyntaxMappingQuery).sweep(sweep);
     }
 }
 
diff --git a/crates/ra_ide_api/src/impls.rs b/crates/ra_ide_api/src/impls.rs
new file mode 100644
index 000000000..469d56d63
--- /dev/null
+++ b/crates/ra_ide_api/src/impls.rs
@@ -0,0 +1,120 @@
+use ra_db::{SourceDatabase};
+use ra_syntax::{
+    AstNode, ast,
+    algo::find_node_at_offset,
+};
+use hir::{db::HirDatabase, source_binder};
+
+use crate::{FilePosition, NavigationTarget, db::RootDatabase, RangeInfo};
+
+pub(crate) fn goto_implementation(
+    db: &RootDatabase,
+    position: FilePosition,
+) -> Option<RangeInfo<Vec<NavigationTarget>>> {
+    let file = db.parse(position.file_id);
+    let syntax = file.syntax();
+
+    let module = source_binder::module_from_position(db, position)?;
+    let krate = module.krate(db)?;
+
+    let node = find_node_at_offset::<ast::NominalDef>(syntax, position.offset)?;
+    let ty = match node.kind() {
+        ast::NominalDefKind::StructDef(def) => {
+            source_binder::struct_from_module(db, module, &def).ty(db)
+        }
+        ast::NominalDefKind::EnumDef(def) => {
+            source_binder::enum_from_module(db, module, &def).ty(db)
+        }
+    };
+
+    let impls = db.impls_in_crate(krate);
+
+    let navs = impls
+        .lookup_impl_blocks(db, &ty)
+        .map(|(module, imp)| NavigationTarget::from_impl_block(db, module, &imp));
+
+    Some(RangeInfo::new(node.syntax().range(), navs.collect()))
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mock_analysis::analysis_and_position;
+
+    fn check_goto(fixuture: &str, expected: &[&str]) {
+        let (analysis, pos) = analysis_and_position(fixuture);
+
+        let navs = analysis.goto_implementation(pos).unwrap().unwrap().info;
+        assert_eq!(navs.len(), expected.len());
+        navs.into_iter()
+            .enumerate()
+            .for_each(|(i, nav)| nav.assert_match(expected[i]));
+    }
+
+    #[test]
+    fn goto_implementation_works() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo<|>;
+            impl Foo {}
+            ",
+            &["impl IMPL_BLOCK FileId(1) [12; 23)"],
+        );
+    }
+
+    #[test]
+    fn goto_implementation_works_multiple_blocks() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo<|>;
+            impl Foo {}
+            impl Foo {}
+            ",
+            &[
+                "impl IMPL_BLOCK FileId(1) [12; 23)",
+                "impl IMPL_BLOCK FileId(1) [24; 35)",
+            ],
+        );
+    }
+
+    #[test]
+    fn goto_implementation_works_multiple_mods() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo<|>;
+            mod a {
+                impl super::Foo {}
+            }
+            mod b {
+                impl super::Foo {}
+            }
+            ",
+            &[
+                "impl IMPL_BLOCK FileId(1) [24; 42)",
+                "impl IMPL_BLOCK FileId(1) [57; 75)",
+            ],
+        );
+    }
+
+    #[test]
+    fn goto_implementation_works_multiple_files() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo<|>;
+            mod a;
+            mod b;
+            //- /a.rs
+            impl crate::Foo {}
+            //- /b.rs
+            impl crate::Foo {}
+            ",
+            &[
+                "impl IMPL_BLOCK FileId(2) [0; 18)",
+                "impl IMPL_BLOCK FileId(3) [0; 18)",
+            ],
+        );
+    }
+}
diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide_api/src/lib.rs
index 43c8bea71..5d8acf9df 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide_api/src/lib.rs
@@ -25,6 +25,7 @@ mod call_info;
 mod syntax_highlighting;
 mod parent_module;
 mod rename;
+mod impls;
 
 #[cfg(test)]
 mod marks;
@@ -58,6 +59,13 @@ pub use ra_ide_api_light::{
 pub use ra_db::{
     Canceled, CrateGraph, CrateId, FileId, FilePosition, FileRange, SourceRootId
 };
+pub use hir::Documentation;
+
+// We use jemalloc mainly to get heap usage statistics, actual performance
+// differnece is not measures.
+#[cfg(feature = "jemalloc")]
+#[global_allocator]
+static ALLOC: jemallocator::Jemalloc = jemallocator::Jemalloc;
 
 pub type Cancelable<T> = Result<T, Canceled>;
 
@@ -260,7 +268,7 @@ impl<T> RangeInfo<T> {
 #[derive(Debug)]
 pub struct CallInfo {
     pub label: String,
-    pub doc: Option<String>,
+    pub doc: Option<Documentation>,
     pub parameters: Vec<String>,
     pub active_parameter: Option<usize>,
 }
@@ -286,6 +294,10 @@ impl AnalysisHost {
         self.db.apply_change(change)
     }
 
+    pub fn maybe_collect_garbage(&mut self) {
+        self.db.maybe_collect_garbage();
+    }
+
     pub fn collect_garbage(&mut self) {
         self.db.collect_garbage();
     }
@@ -405,6 +417,13 @@ impl Analysis {
         self.with_db(|db| goto_definition::goto_definition(db, position))
     }
 
+    pub fn goto_implementation(
+        &self,
+        position: FilePosition,
+    ) -> Cancelable<Option<RangeInfo<Vec<NavigationTarget>>>> {
+        self.with_db(|db| impls::goto_implementation(db, position))
+    }
+
     /// Finds all usages of the reference at point.
     pub fn find_all_refs(&self, position: FilePosition) -> Cancelable<Vec<(FileId, TextRange)>> {
         self.with_db(|db| db.find_all_refs(position))
diff --git a/crates/ra_ide_api/src/mock_analysis.rs b/crates/ra_ide_api/src/mock_analysis.rs
index 846c76cfe..0f2d22ab2 100644
--- a/crates/ra_ide_api/src/mock_analysis.rs
+++ b/crates/ra_ide_api/src/mock_analysis.rs
@@ -2,7 +2,6 @@ use std::sync::Arc;
 
 use relative_path::RelativePathBuf;
 use test_utils::{extract_offset, extract_range, parse_fixture, CURSOR_MARKER};
-use ra_db::mock::FileMap;
 
 use crate::{Analysis, AnalysisChange, AnalysisHost, CrateGraph, FileId, FilePosition, FileRange, SourceRootId};
 
@@ -83,15 +82,14 @@ impl MockAnalysis {
     }
     pub fn analysis_host(self) -> AnalysisHost {
         let mut host = AnalysisHost::default();
-        let mut file_map = FileMap::default();
         let source_root = SourceRootId(0);
         let mut change = AnalysisChange::new();
         change.add_root(source_root, true);
         let mut crate_graph = CrateGraph::default();
-        for (path, contents) in self.files.into_iter() {
+        for (i, (path, contents)) in self.files.into_iter().enumerate() {
             assert!(path.starts_with('/'));
             let path = RelativePathBuf::from_path(&path[1..]).unwrap();
-            let file_id = file_map.add(path.clone());
+            let file_id = FileId(i as u32 + 1);
             if path == "/lib.rs" || path == "/main.rs" {
                 crate_graph.add_crate_root(file_id);
             }
diff --git a/crates/ra_ide_api/src/navigation_target.rs b/crates/ra_ide_api/src/navigation_target.rs
index d73d4afa7..5ccb5cc2e 100644
--- a/crates/ra_ide_api/src/navigation_target.rs
+++ b/crates/ra_ide_api/src/navigation_target.rs
@@ -147,6 +147,16 @@ impl NavigationTarget {
         }
     }
 
+    pub(crate) fn from_impl_block(
+        db: &RootDatabase,
+        module: hir::Module,
+        impl_block: &hir::ImplBlock,
+    ) -> NavigationTarget {
+        let (file_id, _) = module.definition_source(db);
+        let node = module.impl_source(db, impl_block.id());
+        NavigationTarget::from_syntax(file_id, "impl".into(), None, node.syntax())
+    }
+
     #[cfg(test)]
     pub(crate) fn assert_match(&self, expected: &str) {
         let actual = self.debug_render();
diff --git a/crates/ra_ide_api/src/status.rs b/crates/ra_ide_api/src/status.rs
index e11eed223..bd355dd78 100644
--- a/crates/ra_ide_api/src/status.rs
+++ b/crates/ra_ide_api/src/status.rs
@@ -15,9 +15,13 @@ use crate::{
     symbol_index::{SymbolIndex, LibrarySymbolsQuery},
 };
 
+pub(crate) fn syntax_tree_stats(db: &RootDatabase) -> SyntaxTreeStats {
+    db.query(ParseQuery).entries::<SyntaxTreeStats>()
+}
+
 pub(crate) fn status(db: &RootDatabase) -> String {
     let files_stats = db.query(FileTextQuery).entries::<FilesStats>();
-    let syntax_tree_stats = db.query(ParseQuery).entries::<SyntaxTreeStats>();
+    let syntax_tree_stats = syntax_tree_stats(db);
     let symbols_stats = db
         .query(LibrarySymbolsQuery)
         .entries::<LibrarySymbolsStats>();
@@ -26,8 +30,13 @@ pub(crate) fn status(db: &RootDatabase) -> String {
         interner.len()
     };
     format!(
-        "{}\n{}\n{}\nn_defs {}\n",
-        files_stats, symbols_stats, syntax_tree_stats, n_defs
+        "{}\n{}\n{}\n{} defs\n\nmemory:\n{}\ngc {:?} seconds ago",
+        files_stats,
+        symbols_stats,
+        syntax_tree_stats,
+        n_defs,
+        MemoryStats::current(),
+        db.last_gc.elapsed().as_secs(),
     )
 }
 
@@ -58,9 +67,9 @@ impl FromIterator<TableEntry<FileId, Arc<String>>> for FilesStats {
 }
 
 #[derive(Default)]
-struct SyntaxTreeStats {
+pub(crate) struct SyntaxTreeStats {
     total: usize,
-    retained: usize,
+    pub(crate) retained: usize,
     retained_size: Bytes,
 }
 
@@ -118,6 +127,40 @@ impl FromIterator<TableEntry<SourceRootId, Arc<SymbolIndex>>> for LibrarySymbols
     }
 }
 
+struct MemoryStats {
+    allocated: Bytes,
+    resident: Bytes,
+}
+
+impl MemoryStats {
+    #[cfg(feature = "jemalloc")]
+    fn current() -> MemoryStats {
+        jemalloc_ctl::epoch().unwrap();
+        MemoryStats {
+            allocated: Bytes(jemalloc_ctl::stats::allocated().unwrap()),
+            resident: Bytes(jemalloc_ctl::stats::resident().unwrap()),
+        }
+    }
+
+    #[cfg(not(feature = "jemalloc"))]
+    fn current() -> MemoryStats {
+        MemoryStats {
+            allocated: Bytes(0),
+            resident: Bytes(0),
+        }
+    }
+}
+
+impl fmt::Display for MemoryStats {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            fmt,
+            "{} allocated {} resident",
+            self.allocated, self.resident,
+        )
+    }
+}
+
 #[derive(Default)]
 struct Bytes(usize);
 
diff --git a/crates/ra_ide_api/tests/test/main.rs b/crates/ra_ide_api/tests/test/main.rs
index 756075190..c2cb38f7e 100644
--- a/crates/ra_ide_api/tests/test/main.rs
+++ b/crates/ra_ide_api/tests/test/main.rs
@@ -1,9 +1,9 @@
+use insta::assert_debug_snapshot_matches;
 use ra_ide_api::{
-    AnalysisChange,
-    CrateGraph, FileId, mock_analysis::{MockAnalysis, single_file, single_file_with_position}, Query,
+    mock_analysis::{single_file, single_file_with_position, MockAnalysis},
+    AnalysisChange, CrateGraph, FileId, Query,
 };
 use ra_syntax::TextRange;
-use insta::assert_debug_snapshot_matches;
 
 #[test]
 fn test_unresolved_module_diagnostic() {
@@ -26,12 +26,12 @@ fn test_resolve_crate_root() {
         "
         //- /bar.rs
         mod foo;
-        //- /bar/foo.rs
-        // emtpy <|>
+        //- /foo.rs
+        // empty <|>
     ",
     );
     let root_file = mock.id_of("/bar.rs");
-    let mod_file = mock.id_of("/bar/foo.rs");
+    let mod_file = mock.id_of("/foo.rs");
     let mut host = mock.analysis_host();
     assert!(host.analysis().crate_for(mod_file).unwrap().is_empty());
 
diff --git a/crates/ra_ide_api_light/src/assists.rs b/crates/ra_ide_api_light/src/assists.rs
index aea8397c9..8905b0419 100644
--- a/crates/ra_ide_api_light/src/assists.rs
+++ b/crates/ra_ide_api_light/src/assists.rs
@@ -197,6 +197,14 @@ fn check_assist(assist: fn(AssistCtx) -> Option<Assist>, before: &str, after: &s
 }
 
 #[cfg(test)]
+fn check_assist_not_applicable(assist: fn(AssistCtx) -> Option<Assist>, text: &str) {
+    crate::test_utils::check_action_not_applicable(text, |file, off| {
+        let range = TextRange::offset_len(off, 0.into());
+        AssistCtx::new(file, range).apply(assist)
+    })
+}
+
+#[cfg(test)]
 fn check_assist_range(assist: fn(AssistCtx) -> Option<Assist>, before: &str, after: &str) {
     crate::test_utils::check_action_range(before, after, |file, range| {
         AssistCtx::new(file, range).apply(assist)
diff --git a/crates/ra_ide_api_light/src/assists/introduce_variable.rs b/crates/ra_ide_api_light/src/assists/introduce_variable.rs
index 3e4434c23..ed13bddc4 100644
--- a/crates/ra_ide_api_light/src/assists/introduce_variable.rs
+++ b/crates/ra_ide_api_light/src/assists/introduce_variable.rs
@@ -1,16 +1,19 @@
 use ra_syntax::{
     ast::{self, AstNode},
-    SyntaxKind::WHITESPACE,
-    SyntaxNode, TextUnit,
+    SyntaxKind::{
+        WHITESPACE, MATCH_ARM, LAMBDA_EXPR, PATH_EXPR, BREAK_EXPR, LOOP_EXPR, RETURN_EXPR, COMMENT
+    }, SyntaxNode, TextUnit,
 };
 
 use crate::assists::{AssistCtx, Assist};
 
 pub fn introduce_variable<'a>(ctx: AssistCtx) -> Option<Assist> {
     let node = ctx.covering_node();
-    let expr = node.ancestors().filter_map(ast::Expr::cast).next()?;
-
-    let anchor_stmt = anchor_stmt(expr)?;
+    if !valid_covering_node(node) {
+        return None;
+    }
+    let expr = node.ancestors().filter_map(valid_target_expr).next()?;
+    let (anchor_stmt, wrap_in_block) = anchor_stmt(expr)?;
     let indent = anchor_stmt.prev_sibling()?;
     if indent.kind() != WHITESPACE {
         return None;
@@ -18,7 +21,14 @@ pub fn introduce_variable<'a>(ctx: AssistCtx) -> Option<Assist> {
     ctx.build("introduce variable", move |edit| {
         let mut buf = String::new();
 
-        buf.push_str("let var_name = ");
+        let cursor_offset = if wrap_in_block {
+            buf.push_str("{ let var_name = ");
+            TextUnit::of_str("{ let ")
+        } else {
+            buf.push_str("let var_name = ");
+            TextUnit::of_str("let ")
+        };
+
         expr.syntax().text().push_to(&mut buf);
         let full_stmt = ast::ExprStmt::cast(anchor_stmt);
         let is_full_stmt = if let Some(expr_stmt) = full_stmt {
@@ -36,35 +46,64 @@ pub fn introduce_variable<'a>(ctx: AssistCtx) -> Option<Assist> {
             indent.text().push_to(&mut buf);
             edit.replace(expr.syntax().range(), "var_name".to_string());
             edit.insert(anchor_stmt.range().start(), buf);
+            if wrap_in_block {
+                edit.insert(anchor_stmt.range().end(), " }");
+            }
         }
-        edit.set_cursor(anchor_stmt.range().start() + TextUnit::of_str("let "));
+        edit.set_cursor(anchor_stmt.range().start() + cursor_offset);
     })
 }
 
-/// Statement or last in the block expression, which will follow
-/// the freshly introduced var.
-fn anchor_stmt(expr: &ast::Expr) -> Option<&SyntaxNode> {
-    expr.syntax().ancestors().find(|&node| {
+fn valid_covering_node(node: &SyntaxNode) -> bool {
+    node.kind() != COMMENT
+}
+/// Check wether the node is a valid expression which can be extracted to a variable.
+/// In general that's true for any expression, but in some cases that would produce invalid code.
+fn valid_target_expr(node: &SyntaxNode) -> Option<&ast::Expr> {
+    return match node.kind() {
+        PATH_EXPR => None,
+        BREAK_EXPR => ast::BreakExpr::cast(node).and_then(|e| e.expr()),
+        RETURN_EXPR => ast::ReturnExpr::cast(node).and_then(|e| e.expr()),
+        LOOP_EXPR => ast::ReturnExpr::cast(node).and_then(|e| e.expr()),
+        _ => ast::Expr::cast(node),
+    };
+}
+
+/// Returns the syntax node which will follow the freshly introduced var
+/// and a boolean indicating whether we have to wrap it within a { } block
+/// to produce correct code.
+/// It can be a statement, the last in a block expression or a wanna be block
+/// expression like a lamba or match arm.
+fn anchor_stmt(expr: &ast::Expr) -> Option<(&SyntaxNode, bool)> {
+    expr.syntax().ancestors().find_map(|node| {
         if ast::Stmt::cast(node).is_some() {
-            return true;
+            return Some((node, false));
         }
+
         if let Some(expr) = node
             .parent()
             .and_then(ast::Block::cast)
             .and_then(|it| it.expr())
         {
             if expr.syntax() == node {
-                return true;
+                return Some((node, false));
+            }
+        }
+
+        if let Some(parent) = node.parent() {
+            if parent.kind() == MATCH_ARM || parent.kind() == LAMBDA_EXPR {
+                return Some((node, true));
             }
         }
-        false
+
+        None
     })
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::assists::check_assist_range;
+    use crate::assists::{ check_assist, check_assist_not_applicable, check_assist_range };
 
     #[test]
     fn test_introduce_var_simple() {
@@ -161,4 +200,232 @@ fn foo() {
 }",
         );
     }
+
+    #[test]
+    fn test_introduce_var_in_match_arm_no_block() {
+        check_assist_range(
+            introduce_variable,
+            "
+fn main() {
+    let x = true;
+    let tuple = match x {
+        true => (<|>2 + 2<|>, true)
+        _ => (0, false)
+    };
+}
+",
+            "
+fn main() {
+    let x = true;
+    let tuple = match x {
+        true => { let <|>var_name = 2 + 2; (var_name, true) }
+        _ => (0, false)
+    };
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_introduce_var_in_match_arm_with_block() {
+        check_assist_range(
+            introduce_variable,
+            "
+fn main() {
+    let x = true;
+    let tuple = match x {
+        true => {
+            let y = 1;
+            (<|>2 + y<|>, true)
+        }
+        _ => (0, false)
+    };
+}
+",
+            "
+fn main() {
+    let x = true;
+    let tuple = match x {
+        true => {
+            let y = 1;
+            let <|>var_name = 2 + y;
+            (var_name, true)
+        }
+        _ => (0, false)
+    };
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_introduce_var_in_closure_no_block() {
+        check_assist_range(
+            introduce_variable,
+            "
+fn main() {
+    let lambda = |x: u32| <|>x * 2<|>;
+}
+",
+            "
+fn main() {
+    let lambda = |x: u32| { let <|>var_name = x * 2; var_name };
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_introduce_var_in_closure_with_block() {
+        check_assist_range(
+            introduce_variable,
+            "
+fn main() {
+    let lambda = |x: u32| { <|>x * 2<|> };
+}
+",
+            "
+fn main() {
+    let lambda = |x: u32| { let <|>var_name = x * 2; var_name };
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_introduce_var_path_simple() {
+        check_assist(
+            introduce_variable,
+            "
+fn main() {
+    let o = S<|>ome(true);
+}
+",
+            "
+fn main() {
+    let <|>var_name = Some(true);
+    let o = var_name;
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_introduce_var_path_method() {
+        check_assist(
+            introduce_variable,
+            "
+fn main() {
+    let v = b<|>ar.foo();
+}
+",
+            "
+fn main() {
+    let <|>var_name = bar.foo();
+    let v = var_name;
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_introduce_var_return() {
+        check_assist(
+            introduce_variable,
+            "
+fn foo() -> u32 {
+    r<|>eturn 2 + 2;
+}
+",
+            "
+fn foo() -> u32 {
+    let <|>var_name = 2 + 2;
+    return var_name;
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_introduce_var_break() {
+        check_assist(
+            introduce_variable,
+            "
+fn main() {
+    let result = loop {
+        b<|>reak 2 + 2;
+    };
+}
+",
+            "
+fn main() {
+    let result = loop {
+        let <|>var_name = 2 + 2;
+        break var_name;
+    };
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_introduce_var_for_cast() {
+        check_assist(
+            introduce_variable,
+            "
+fn main() {
+    let v = 0f32 a<|>s u32;
+}
+",
+            "
+fn main() {
+    let <|>var_name = 0f32 as u32;
+    let v = var_name;
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_introduce_var_for_return_not_applicable() {
+        check_assist_not_applicable(
+            introduce_variable,
+            "
+fn foo() {
+    r<|>eturn;
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_introduce_var_for_break_not_applicable() {
+        check_assist_not_applicable(
+            introduce_variable,
+            "
+fn main() {
+    loop {
+        b<|>reak;
+    };
+}
+",
+        );
+    }
+
+    #[test]
+    fn test_introduce_var_in_comment_not_applicable() {
+        check_assist_not_applicable(
+            introduce_variable,
+            "
+fn main() {
+    let x = true;
+    let tuple = match x {
+        // c<|>omment
+        true => (2 + 2, true)
+        _ => (0, false)
+    };
+}
+",
+        );
+    }
 }
diff --git a/crates/ra_ide_api_light/src/test_utils.rs b/crates/ra_ide_api_light/src/test_utils.rs
index dc2470aa3..22ded2435 100644
--- a/crates/ra_ide_api_light/src/test_utils.rs
+++ b/crates/ra_ide_api_light/src/test_utils.rs
@@ -23,6 +23,18 @@ pub fn check_action<F: Fn(&SourceFile, TextUnit) -> Option<LocalEdit>>(
     assert_eq_text!(after, &actual);
 }
 
+pub fn check_action_not_applicable<F: Fn(&SourceFile, TextUnit) -> Option<LocalEdit>>(
+    text: &str,
+    f: F,
+) {
+    let (text_cursor_pos, text) = extract_offset(text);
+    let file = SourceFile::parse(&text);
+    assert!(
+        f(&file, text_cursor_pos).is_none(),
+        "code action is applicable but it shouldn't"
+    );
+}
+
 pub fn check_action_range<F: Fn(&SourceFile, TextRange) -> Option<LocalEdit>>(
     before: &str,
     after: &str,
diff --git a/crates/ra_lsp_server/Cargo.toml b/crates/ra_lsp_server/Cargo.toml
index 160d2f672..bb92747f2 100644
--- a/crates/ra_lsp_server/Cargo.toml
+++ b/crates/ra_lsp_server/Cargo.toml
@@ -34,3 +34,6 @@ ra_vfs = { path = "../ra_vfs" }
 [dev-dependencies]
 tempfile = "3"
 test_utils = { path = "../test_utils" }
+
+[features]
+jemalloc = [ "ra_ide_api/jemalloc" ]
diff --git a/crates/ra_lsp_server/src/caps.rs b/crates/ra_lsp_server/src/caps.rs
index bca079d65..254624487 100644
--- a/crates/ra_lsp_server/src/caps.rs
+++ b/crates/ra_lsp_server/src/caps.rs
@@ -2,7 +2,7 @@ use lsp_types::{
     CodeActionProviderCapability, CodeLensOptions, CompletionOptions, DocumentOnTypeFormattingOptions,
     ExecuteCommandOptions, FoldingRangeProviderCapability, RenameOptions, RenameProviderCapability,
     ServerCapabilities, SignatureHelpOptions, TextDocumentSyncCapability, TextDocumentSyncKind,
-    TextDocumentSyncOptions,
+    TextDocumentSyncOptions, ImplementationProviderCapability,
 };
 
 pub fn server_capabilities() -> ServerCapabilities {
@@ -26,7 +26,7 @@ pub fn server_capabilities() -> ServerCapabilities {
         }),
         definition_provider: Some(true),
         type_definition_provider: None,
-        implementation_provider: None,
+        implementation_provider: Some(ImplementationProviderCapability::Simple(true)),
         references_provider: Some(true),
         document_highlight_provider: Some(true),
         document_symbol_provider: Some(true),
diff --git a/crates/ra_lsp_server/src/conv.rs b/crates/ra_lsp_server/src/conv.rs
index 8c87f5195..c033ecdea 100644
--- a/crates/ra_lsp_server/src/conv.rs
+++ b/crates/ra_lsp_server/src/conv.rs
@@ -87,13 +87,6 @@ impl ConvWith for CompletionItem {
             None
         };
 
-        let documentation = self.documentation().map(|value| {
-            Documentation::MarkupContent(MarkupContent {
-                kind: MarkupKind::Markdown,
-                value: value.to_string(),
-            })
-        });
-
         let mut res = lsp_types::CompletionItem {
             label: self.label().to_string(),
             detail: self.detail().map(|it| it.to_string()),
@@ -101,7 +94,7 @@ impl ConvWith for CompletionItem {
             kind: self.kind().map(|it| it.conv()),
             text_edit: Some(text_edit),
             additional_text_edits,
-            documentation: documentation,
+            documentation: self.documentation().map(|it| it.conv()),
             ..Default::default()
         };
         res.insert_text_format = Some(match self.insert_text_format() {
@@ -160,6 +153,16 @@ impl ConvWith for Range {
     }
 }
 
+impl Conv for ra_ide_api::Documentation {
+    type Output = lsp_types::Documentation;
+    fn conv(self) -> Documentation {
+        Documentation::MarkupContent(MarkupContent {
+            kind: MarkupKind::Markdown,
+            value: crate::markdown::sanitize_markdown(self).into(),
+        })
+    }
+}
+
 impl ConvWith for TextEdit {
     type Ctx = LineIndex;
     type Output = Vec<lsp_types::TextEdit>;
diff --git a/crates/ra_lsp_server/src/lib.rs b/crates/ra_lsp_server/src/lib.rs
index f93d4b37d..5b5f3b948 100644
--- a/crates/ra_lsp_server/src/lib.rs
+++ b/crates/ra_lsp_server/src/lib.rs
@@ -2,6 +2,7 @@ mod caps;
 mod cargo_target_spec;
 mod conv;
 mod main_loop;
+mod markdown;
 mod project_model;
 pub mod req;
 mod server_world;
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index ddd20a41f..df390c19e 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -172,6 +172,7 @@ fn main_loop_inner(
 
     let (libdata_sender, libdata_receiver) = unbounded();
     loop {
+        state.maybe_collect_garbage();
         log::trace!("selecting");
         let event = select! {
             recv(msg_receiver) -> msg => match msg {
@@ -207,7 +208,7 @@ fn main_loop_inner(
                     };
                     match req.cast::<req::CollectGarbage>() {
                         Ok((id, ())) => {
-                            state.collect_garbadge();
+                            state.collect_garbage();
                             let resp = RawResponse::ok::<req::CollectGarbage>(id, &());
                             msg_sender.send(RawMessage::Response(resp)).unwrap()
                         }
@@ -304,6 +305,7 @@ fn on_request(
         .on::<req::DocumentSymbolRequest>(handlers::handle_document_symbol)?
         .on::<req::WorkspaceSymbol>(handlers::handle_workspace_symbol)?
         .on::<req::GotoDefinition>(handlers::handle_goto_definition)?
+        .on::<req::GotoImplementation>(handlers::handle_goto_implementation)?
         .on::<req::ParentModule>(handlers::handle_parent_module)?
         .on::<req::Runnables>(handlers::handle_runnables)?
         .on::<req::DecorationsRequest>(handlers::handle_decorations)?
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index ace3da020..74554f15c 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -1,7 +1,7 @@
 use gen_lsp_server::ErrorCode;
 use lsp_types::{
     CodeActionResponse, CodeLens, Command, Diagnostic, DiagnosticSeverity,
-    DocumentFormattingParams, DocumentHighlight, DocumentSymbol, Documentation, FoldingRange,
+    DocumentFormattingParams, DocumentHighlight, DocumentSymbol, FoldingRange,
     FoldingRangeKind, FoldingRangeParams, Hover, HoverContents, Location, MarkupContent,
     MarkupKind, ParameterInformation, ParameterLabel, Position, PrepareRenameResponse, Range,
     RenameParams, SignatureInformation, SymbolInformation, TextDocumentIdentifier, TextEdit,
@@ -229,6 +229,26 @@ pub fn handle_goto_definition(
     Ok(Some(req::GotoDefinitionResponse::Link(res)))
 }
 
+pub fn handle_goto_implementation(
+    world: ServerWorld,
+    params: req::TextDocumentPositionParams,
+) -> Result<Option<req::GotoImplementationResponse>> {
+    let position = params.try_conv_with(&world)?;
+    let line_index = world.analysis().file_line_index(position.file_id);
+    let nav_info = match world.analysis().goto_implementation(position)? {
+        None => return Ok(None),
+        Some(it) => it,
+    };
+    let nav_range = nav_info.range;
+    let res = nav_info
+        .info
+        .into_iter()
+        .map(|nav| RangeInfo::new(nav_range, nav))
+        .map(|nav| to_location_link(&nav, &world, &line_index))
+        .collect::<Result<Vec<_>>>()?;
+    Ok(Some(req::GotoDefinitionResponse::Link(res)))
+}
+
 pub fn handle_parent_module(
     world: ServerWorld,
     params: req::TextDocumentPositionParams,
@@ -401,12 +421,9 @@ pub fn handle_signature_help(
                 documentation: None,
             })
             .collect();
-        let documentation = call_info.doc.map(|value| {
-            Documentation::MarkupContent(MarkupContent {
-                kind: MarkupKind::Markdown,
-                value,
-            })
-        });
+
+        let documentation = call_info.doc.map(|it| it.conv());
+
         let sig_info = SignatureInformation {
             label: call_info.label,
             documentation,
@@ -581,7 +598,7 @@ pub fn handle_code_action(
         let edit = source_edit.try_conv_with(&world)?;
         let cmd = Command {
             title,
-            command: "ra-lsp.applySourceChange".to_string(),
+            command: "rust-analyzer.applySourceChange".to_string(),
             arguments: Some(vec![to_value(edit).unwrap()]),
         };
         res.push(cmd);
@@ -623,7 +640,7 @@ pub fn handle_code_lens(
                 range,
                 command: Some(Command {
                     title: title.into(),
-                    command: "ra-lsp.run-single".into(),
+                    command: "rust-analyzer.runSingle".into(),
                     arguments: Some(vec![to_value(r).unwrap()]),
                 }),
                 data: None,
diff --git a/crates/ra_lsp_server/src/markdown.rs b/crates/ra_lsp_server/src/markdown.rs
new file mode 100644
index 000000000..f505755e8
--- /dev/null
+++ b/crates/ra_lsp_server/src/markdown.rs
@@ -0,0 +1,38 @@
+use ra_ide_api::Documentation;
+
+pub(crate) fn sanitize_markdown(docs: Documentation) -> Documentation {
+    let docs: String = docs.into();
+
+    // Massage markdown
+    let mut processed_lines = Vec::new();
+    let mut in_code_block = false;
+    for line in docs.lines() {
+        if line.starts_with("```") {
+            in_code_block = !in_code_block;
+        }
+
+        let line = if in_code_block && line.starts_with("```") && !line.contains("rust") {
+            "```rust".into()
+        } else {
+            line.to_string()
+        };
+
+        processed_lines.push(line);
+    }
+
+    Documentation::new(&processed_lines.join("\n"))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_codeblock_adds_rust() {
+        let comment = "```\nfn some_rust() {}\n```";
+        assert_eq!(
+            sanitize_markdown(Documentation::new(comment)).contents(),
+            "```rust\nfn some_rust() {}\n```"
+        );
+    }
+}
diff --git a/crates/ra_lsp_server/src/req.rs b/crates/ra_lsp_server/src/req.rs
index 5968e592b..e224ede80 100644
--- a/crates/ra_lsp_server/src/req.rs
+++ b/crates/ra_lsp_server/src/req.rs
@@ -8,7 +8,7 @@ pub use lsp_types::{
     CompletionParams, CompletionResponse, DocumentOnTypeFormattingParams, DocumentSymbolParams,
     DocumentSymbolResponse, ExecuteCommandParams, Hover, InitializeResult,
     PublishDiagnosticsParams, ReferenceParams, SignatureHelp, TextDocumentEdit,
-    TextDocumentPositionParams, TextEdit, WorkspaceEdit, WorkspaceSymbolParams,
+    TextDocumentPositionParams, TextEdit, WorkspaceEdit, WorkspaceSymbolParams
 };
 
 pub enum AnalyzerStatus {}
@@ -16,7 +16,7 @@ pub enum AnalyzerStatus {}
 impl Request for AnalyzerStatus {
     type Params = ();
     type Result = String;
-    const METHOD: &'static str = "ra/analyzerStatus";
+    const METHOD: &'static str = "rust-analyzer/analyzerStatus";
 }
 
 pub enum CollectGarbage {}
@@ -24,7 +24,7 @@ pub enum CollectGarbage {}
 impl Request for CollectGarbage {
     type Params = ();
     type Result = ();
-    const METHOD: &'static str = "ra/collectGarbage";
+    const METHOD: &'static str = "rust-analyzer/collectGarbage";
 }
 
 pub enum SyntaxTree {}
@@ -32,7 +32,7 @@ pub enum SyntaxTree {}
 impl Request for SyntaxTree {
     type Params = SyntaxTreeParams;
     type Result = String;
-    const METHOD: &'static str = "m/syntaxTree";
+    const METHOD: &'static str = "rust-analyzer/syntaxTree";
 }
 
 #[derive(Deserialize, Debug)]
@@ -46,7 +46,7 @@ pub enum ExtendSelection {}
 impl Request for ExtendSelection {
     type Params = ExtendSelectionParams;
     type Result = ExtendSelectionResult;
-    const METHOD: &'static str = "m/extendSelection";
+    const METHOD: &'static str = "rust-analyzer/extendSelection";
 }
 
 #[derive(Deserialize, Debug)]
@@ -67,7 +67,7 @@ pub enum FindMatchingBrace {}
 impl Request for FindMatchingBrace {
     type Params = FindMatchingBraceParams;
     type Result = Vec<Position>;
-    const METHOD: &'static str = "m/findMatchingBrace";
+    const METHOD: &'static str = "rust-analyzer/findMatchingBrace";
 }
 
 #[derive(Deserialize, Debug)]
@@ -82,14 +82,14 @@ pub enum DecorationsRequest {}
 impl Request for DecorationsRequest {
     type Params = TextDocumentIdentifier;
     type Result = Vec<Decoration>;
-    const METHOD: &'static str = "m/decorationsRequest";
+    const METHOD: &'static str = "rust-analyzer/decorationsRequest";
 }
 
 pub enum PublishDecorations {}
 
 impl Notification for PublishDecorations {
     type Params = PublishDecorationsParams;
-    const METHOD: &'static str = "m/publishDecorations";
+    const METHOD: &'static str = "rust-analyzer/publishDecorations";
 }
 
 #[derive(Serialize, Debug)]
@@ -112,7 +112,7 @@ pub enum ParentModule {}
 impl Request for ParentModule {
     type Params = TextDocumentPositionParams;
     type Result = Vec<Location>;
-    const METHOD: &'static str = "m/parentModule";
+    const METHOD: &'static str = "rust-analyzer/parentModule";
 }
 
 pub enum JoinLines {}
@@ -120,7 +120,7 @@ pub enum JoinLines {}
 impl Request for JoinLines {
     type Params = JoinLinesParams;
     type Result = SourceChange;
-    const METHOD: &'static str = "m/joinLines";
+    const METHOD: &'static str = "rust-analyzer/joinLines";
 }
 
 #[derive(Deserialize, Debug)]
@@ -135,7 +135,7 @@ pub enum OnEnter {}
 impl Request for OnEnter {
     type Params = TextDocumentPositionParams;
     type Result = Option<SourceChange>;
-    const METHOD: &'static str = "m/onEnter";
+    const METHOD: &'static str = "rust-analyzer/onEnter";
 }
 
 pub enum Runnables {}
@@ -143,7 +143,7 @@ pub enum Runnables {}
 impl Request for Runnables {
     type Params = RunnablesParams;
     type Result = Vec<Runnable>;
-    const METHOD: &'static str = "m/runnables";
+    const METHOD: &'static str = "rust-analyzer/runnables";
 }
 
 #[derive(Serialize, Deserialize, Debug)]
diff --git a/crates/ra_lsp_server/src/server_world.rs b/crates/ra_lsp_server/src/server_world.rs
index bf04f1125..c2167c5d8 100644
--- a/crates/ra_lsp_server/src/server_world.rs
+++ b/crates/ra_lsp_server/src/server_world.rs
@@ -232,7 +232,11 @@ impl ServerWorldState {
         }
     }
 
-    pub fn collect_garbadge(&mut self) {
+    pub fn maybe_collect_garbage(&mut self) {
+        self.analysis_host.maybe_collect_garbage()
+    }
+
+    pub fn collect_garbage(&mut self) {
         self.analysis_host.collect_garbage()
     }
 }
diff --git a/crates/ra_lsp_server/tests/heavy_tests/main.rs b/crates/ra_lsp_server/tests/heavy_tests/main.rs
index 8b5c43a09..bfb0645a8 100644
--- a/crates/ra_lsp_server/tests/heavy_tests/main.rs
+++ b/crates/ra_lsp_server/tests/heavy_tests/main.rs
@@ -246,7 +246,7 @@ fn main() {}
                   "label": "create module"
                 }
               ],
-              "command": "ra-lsp.applySourceChange",
+              "command": "rust-analyzer.applySourceChange",
               "title": "create module"
             }
         ]),
diff --git a/crates/ra_syntax/src/algo.rs b/crates/ra_syntax/src/algo.rs
index 45747e21d..99b0983b0 100644
--- a/crates/ra_syntax/src/algo.rs
+++ b/crates/ra_syntax/src/algo.rs
@@ -17,14 +17,14 @@ pub fn find_leaf_at_offset(node: &SyntaxNode, offset: TextUnit) -> LeafAtOffset<
 }
 
 /// Finds a node of specific Ast type at offset. Note that this is slightly
-/// impercise: if the cursor is strictly betwen two nodes of the desired type,
+/// imprecise: if the cursor is strictly between two nodes of the desired type,
 /// as in
 ///
 /// ```no-run
 /// struct Foo {}|struct Bar;
 /// ```
 ///
-/// then the left node will be silently prefered.
+/// then the left node will be silently preferred.
 pub fn find_node_at_offset<N: AstNode>(syntax: &SyntaxNode, offset: TextUnit) -> Option<&N> {
     find_leaf_at_offset(syntax, offset).find_map(|leaf| leaf.ancestors().find_map(N::cast))
 }
diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index ce559882b..d0561c495 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -1982,7 +1982,11 @@ impl ToOwned for MatchGuard {
 }
 
 
-impl MatchGuard {}
+impl MatchGuard {
+    pub fn expr(&self) -> Option<&Expr> {
+        super::child_opt(self)
+    }
+}
 
 // MethodCallExpr
 #[derive(Debug, PartialEq, Eq, Hash)]
diff --git a/crates/ra_syntax/src/grammar.ron b/crates/ra_syntax/src/grammar.ron
index f4841241f..d4c863705 100644
--- a/crates/ra_syntax/src/grammar.ron
+++ b/crates/ra_syntax/src/grammar.ron
@@ -418,7 +418,7 @@ Grammar(
             ],
             collections: [ [ "pats", "Pat" ] ]
         ),
-        "MatchGuard": (),
+        "MatchGuard": (options: ["Expr"]),
         "StructLit": (options: ["Path", "NamedFieldList", ["spread", "Expr"]]),
         "NamedFieldList": (collections: [ ["fields", "NamedField"] ]),
         "NamedField": (options: ["NameRef", "Expr"]),
diff --git a/crates/ra_syntax/src/grammar/expressions/atom.rs b/crates/ra_syntax/src/grammar/expressions/atom.rs
index 6d6d89f70..600774afd 100644
--- a/crates/ra_syntax/src/grammar/expressions/atom.rs
+++ b/crates/ra_syntax/src/grammar/expressions/atom.rs
@@ -360,8 +360,8 @@ fn match_arm(p: &mut Parser) -> BlockLike {
     while p.eat(PIPE) {
         patterns::pattern(p);
     }
-    if p.eat(IF_KW) {
-        expr(p);
+    if p.at(IF_KW) {
+        match_guard(p);
     }
     p.expect(FAT_ARROW);
     let ret = expr_stmt(p);
@@ -369,6 +369,20 @@ fn match_arm(p: &mut Parser) -> BlockLike {
     ret
 }
 
+// test match_guard
+// fn foo() {
+//     match () {
+//         _ if foo => (),
+//     }
+// }
+fn match_guard(p: &mut Parser) -> CompletedMarker {
+    assert!(p.at(IF_KW));
+    let m = p.start();
+    p.bump();
+    expr(p);
+    m.complete(p, MATCH_GUARD)
+}
+
 // test block_expr
 // fn foo() {
 //     {};
diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0066_match_arm.txt b/crates/ra_syntax/tests/data/parser/inline/ok/0066_match_arm.txt
index 98e7535a3..b44e61879 100644
--- a/crates/ra_syntax/tests/data/parser/inline/ok/0066_match_arm.txt
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0066_match_arm.txt
@@ -37,32 +37,33 @@ SOURCE_FILE@[0; 167)
               PLACEHOLDER_PAT@[51; 52)
                 UNDERSCORE@[51; 52)
               WHITESPACE@[52; 53)
-              IF_KW@[53; 55)
-              WHITESPACE@[55; 56)
-              BIN_EXPR@[56; 77)
-                PATH_EXPR@[56; 60)
-                  PATH@[56; 60)
-                    PATH_SEGMENT@[56; 60)
-                      NAME_REF@[56; 60)
-                        IDENT@[56; 60) "Test"
-                WHITESPACE@[60; 61)
-                R_ANGLE@[61; 62)
-                WHITESPACE@[62; 63)
-                STRUCT_LIT@[63; 77)
-                  PATH@[63; 67)
-                    PATH_SEGMENT@[63; 67)
-                      NAME_REF@[63; 67)
-                        IDENT@[63; 67) "Test"
-                  NAMED_FIELD_LIST@[67; 77)
-                    L_CURLY@[67; 68)
-                    NAMED_FIELD@[68; 76)
-                      NAME_REF@[68; 73)
-                        IDENT@[68; 73) "field"
-                      COLON@[73; 74)
-                      WHITESPACE@[74; 75)
-                      LITERAL@[75; 76)
-                        INT_NUMBER@[75; 76) "0"
-                    R_CURLY@[76; 77)
+              MATCH_GUARD@[53; 77)
+                IF_KW@[53; 55)
+                WHITESPACE@[55; 56)
+                BIN_EXPR@[56; 77)
+                  PATH_EXPR@[56; 60)
+                    PATH@[56; 60)
+                      PATH_SEGMENT@[56; 60)
+                        NAME_REF@[56; 60)
+                          IDENT@[56; 60) "Test"
+                  WHITESPACE@[60; 61)
+                  R_ANGLE@[61; 62)
+                  WHITESPACE@[62; 63)
+                  STRUCT_LIT@[63; 77)
+                    PATH@[63; 67)
+                      PATH_SEGMENT@[63; 67)
+                        NAME_REF@[63; 67)
+                          IDENT@[63; 67) "Test"
+                    NAMED_FIELD_LIST@[67; 77)
+                      L_CURLY@[67; 68)
+                      NAMED_FIELD@[68; 76)
+                        NAME_REF@[68; 73)
+                          IDENT@[68; 73) "field"
+                        COLON@[73; 74)
+                        WHITESPACE@[74; 75)
+                        LITERAL@[75; 76)
+                          INT_NUMBER@[75; 76) "0"
+                      R_CURLY@[76; 77)
               WHITESPACE@[77; 78)
               FAT_ARROW@[78; 80)
               WHITESPACE@[80; 81)
@@ -82,13 +83,14 @@ SOURCE_FILE@[0; 167)
                 NAME@[97; 98)
                   IDENT@[97; 98) "Y"
               WHITESPACE@[98; 99)
-              IF_KW@[99; 101)
-              WHITESPACE@[101; 102)
-              PATH_EXPR@[102; 103)
-                PATH@[102; 103)
-                  PATH_SEGMENT@[102; 103)
-                    NAME_REF@[102; 103)
-                      IDENT@[102; 103) "Z"
+              MATCH_GUARD@[99; 103)
+                IF_KW@[99; 101)
+                WHITESPACE@[101; 102)
+                PATH_EXPR@[102; 103)
+                  PATH@[102; 103)
+                    PATH_SEGMENT@[102; 103)
+                      NAME_REF@[102; 103)
+                        IDENT@[102; 103) "Z"
               WHITESPACE@[103; 104)
               FAT_ARROW@[104; 106)
               WHITESPACE@[106; 107)
@@ -110,13 +112,14 @@ SOURCE_FILE@[0; 167)
                 NAME@[125; 126)
                   IDENT@[125; 126) "Y"
               WHITESPACE@[126; 127)
-              IF_KW@[127; 129)
-              WHITESPACE@[129; 130)
-              PATH_EXPR@[130; 131)
-                PATH@[130; 131)
-                  PATH_SEGMENT@[130; 131)
-                    NAME_REF@[130; 131)
-                      IDENT@[130; 131) "Z"
+              MATCH_GUARD@[127; 131)
+                IF_KW@[127; 129)
+                WHITESPACE@[129; 130)
+                PATH_EXPR@[130; 131)
+                  PATH@[130; 131)
+                    PATH_SEGMENT@[130; 131)
+                      NAME_REF@[130; 131)
+                        IDENT@[130; 131) "Z"
               WHITESPACE@[131; 132)
               FAT_ARROW@[132; 134)
               WHITESPACE@[134; 135)
diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0118_match_guard.rs b/crates/ra_syntax/tests/data/parser/inline/ok/0118_match_guard.rs
new file mode 100644
index 000000000..f1bd72fc4
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0118_match_guard.rs
@@ -0,0 +1,5 @@
+fn foo() {
+    match () {
+        _ if foo => (),
+    }
+}
diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0118_match_guard.txt b/crates/ra_syntax/tests/data/parser/inline/ok/0118_match_guard.txt
new file mode 100644
index 000000000..27553882d
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0118_match_guard.txt
@@ -0,0 +1,47 @@
+SOURCE_FILE@[0; 58)
+  FN_DEF@[0; 57)
+    FN_KW@[0; 2)
+    WHITESPACE@[2; 3)
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7)
+      R_PAREN@[7; 8)
+    WHITESPACE@[8; 9)
+    BLOCK@[9; 57)
+      L_CURLY@[9; 10)
+      WHITESPACE@[10; 15)
+      MATCH_EXPR@[15; 55)
+        MATCH_KW@[15; 20)
+        WHITESPACE@[20; 21)
+        TUPLE_EXPR@[21; 23)
+          L_PAREN@[21; 22)
+          R_PAREN@[22; 23)
+        WHITESPACE@[23; 24)
+        MATCH_ARM_LIST@[24; 55)
+          L_CURLY@[24; 25)
+          WHITESPACE@[25; 34)
+          MATCH_ARM@[34; 48)
+            PLACEHOLDER_PAT@[34; 35)
+              UNDERSCORE@[34; 35)
+            WHITESPACE@[35; 36)
+            MATCH_GUARD@[36; 42)
+              IF_KW@[36; 38)
+              WHITESPACE@[38; 39)
+              PATH_EXPR@[39; 42)
+                PATH@[39; 42)
+                  PATH_SEGMENT@[39; 42)
+                    NAME_REF@[39; 42)
+                      IDENT@[39; 42) "foo"
+            WHITESPACE@[42; 43)
+            FAT_ARROW@[43; 45)
+            WHITESPACE@[45; 46)
+            TUPLE_EXPR@[46; 48)
+              L_PAREN@[46; 47)
+              R_PAREN@[47; 48)
+          COMMA@[48; 49)
+          WHITESPACE@[49; 54)
+          R_CURLY@[54; 55)
+      WHITESPACE@[55; 56)
+      R_CURLY@[56; 57)
+  WHITESPACE@[57; 58)