76 files changed, 2355 insertions, 855 deletions

diff --git a/crates/ra_assists/src/handlers/auto_import.rs b/crates/ra_assists/src/handlers/auto_import.rs
index 1fb701da5..c4aea2a06 100644
--- a/crates/ra_assists/src/handlers/auto_import.rs
+++ b/crates/ra_assists/src/handlers/auto_import.rs
@@ -1,10 +1,18 @@
-use ra_ide_db::imports_locator::ImportsLocator;
-use ra_syntax::ast::{self, AstNode};
-
 use crate::{
     assist_ctx::{Assist, AssistCtx},
     insert_use_statement, AssistId,
 };
+use hir::{
+    db::HirDatabase, AsAssocItem, AssocItemContainer, ModPath, Module, ModuleDef, PathResolution,
+    SourceAnalyzer, Trait, Type,
+};
+use ra_ide_db::{imports_locator::ImportsLocator, RootDatabase};
+use ra_prof::profile;
+use ra_syntax::{
+    ast::{self, AstNode},
+    SyntaxNode,
+};
+use rustc_hash::FxHashSet;
 use std::collections::BTreeSet;
 
 // Assist: auto_import
@@ -27,52 +35,24 @@ use std::collections::BTreeSet;
 // # pub mod std { pub mod collections { pub struct HashMap { } } }
 // ```
 pub(crate) fn auto_import(ctx: AssistCtx) -> Option<Assist> {
-    let path_under_caret: ast::Path = ctx.find_node_at_offset()?;
-    if path_under_caret.syntax().ancestors().find_map(ast::UseItem::cast).is_some() {
-        return None;
-    }
-
-    let module = path_under_caret.syntax().ancestors().find_map(ast::Module::cast);
-    let position = match module.and_then(|it| it.item_list()) {
-        Some(item_list) => item_list.syntax().clone(),
-        None => {
-            let current_file =
-                path_under_caret.syntax().ancestors().find_map(ast::SourceFile::cast)?;
-            current_file.syntax().clone()
-        }
-    };
-    let source_analyzer = ctx.source_analyzer(&position, None);
-    let module_with_name_to_import = source_analyzer.module()?;
-
-    let name_ref_to_import =
-        path_under_caret.syntax().descendants().find_map(ast::NameRef::cast)?;
-    if source_analyzer
-        .resolve_path(ctx.db, &name_ref_to_import.syntax().ancestors().find_map(ast::Path::cast)?)
-        .is_some()
-    {
-        return None;
-    }
-
-    let name_to_import = name_ref_to_import.syntax().to_string();
-    let proposed_imports = ImportsLocator::new(ctx.db)
-        .find_imports(&name_to_import)
-        .into_iter()
-        .filter_map(|module_def| module_with_name_to_import.find_use_path(ctx.db, module_def))
-        .filter(|use_path| !use_path.segments.is_empty())
-        .take(20)
-        .collect::<BTreeSet<_>>();
-
+    let auto_import_assets = AutoImportAssets::new(&ctx)?;
+    let proposed_imports = auto_import_assets.search_for_imports(ctx.db);
     if proposed_imports.is_empty() {
         return None;
     }
 
-    let mut group = ctx.add_assist_group(format!("Import {}", name_to_import));
+    let assist_group_name = if proposed_imports.len() == 1 {
+        format!("Import `{}`", proposed_imports.iter().next().unwrap())
+    } else {
+        auto_import_assets.get_import_group_message()
+    };
+    let mut group = ctx.add_assist_group(assist_group_name);
     for import in proposed_imports {
         group.add_assist(AssistId("auto_import"), format!("Import `{}`", &import), |edit| {
-            edit.target(path_under_caret.syntax().text_range());
+            edit.target(auto_import_assets.syntax_under_caret.text_range());
             insert_use_statement(
-                &position,
-                path_under_caret.syntax(),
+                &auto_import_assets.syntax_under_caret,
+                &auto_import_assets.syntax_under_caret,
                 &import,
                 edit.text_edit_builder(),
             );
@@ -81,11 +61,232 @@ pub(crate) fn auto_import(ctx: AssistCtx) -> Option<Assist> {
     group.finish()
 }
 
+struct AutoImportAssets {
+    import_candidate: ImportCandidate,
+    module_with_name_to_import: Module,
+    syntax_under_caret: SyntaxNode,
+}
+
+impl AutoImportAssets {
+    fn new(ctx: &AssistCtx) -> Option<Self> {
+        if let Some(path_under_caret) = ctx.find_node_at_offset::<ast::Path>() {
+            Self::for_regular_path(path_under_caret, &ctx)
+        } else {
+            Self::for_method_call(ctx.find_node_at_offset()?, &ctx)
+        }
+    }
+
+    fn for_method_call(method_call: ast::MethodCallExpr, ctx: &AssistCtx) -> Option<Self> {
+        let syntax_under_caret = method_call.syntax().to_owned();
+        let source_analyzer = ctx.source_analyzer(&syntax_under_caret, None);
+        let module_with_name_to_import = source_analyzer.module()?;
+        Some(Self {
+            import_candidate: ImportCandidate::for_method_call(
+                &method_call,
+                &source_analyzer,
+                ctx.db,
+            )?,
+            module_with_name_to_import,
+            syntax_under_caret,
+        })
+    }
+
+    fn for_regular_path(path_under_caret: ast::Path, ctx: &AssistCtx) -> Option<Self> {
+        let syntax_under_caret = path_under_caret.syntax().to_owned();
+        if syntax_under_caret.ancestors().find_map(ast::UseItem::cast).is_some() {
+            return None;
+        }
+
+        let source_analyzer = ctx.source_analyzer(&syntax_under_caret, None);
+        let module_with_name_to_import = source_analyzer.module()?;
+        Some(Self {
+            import_candidate: ImportCandidate::for_regular_path(
+                &path_under_caret,
+                &source_analyzer,
+                ctx.db,
+            )?,
+            module_with_name_to_import,
+            syntax_under_caret,
+        })
+    }
+
+    fn get_search_query(&self) -> &str {
+        match &self.import_candidate {
+            ImportCandidate::UnqualifiedName(name) => name,
+            ImportCandidate::QualifierStart(qualifier_start) => qualifier_start,
+            ImportCandidate::TraitAssocItem(_, trait_assoc_item_name) => trait_assoc_item_name,
+            ImportCandidate::TraitMethod(_, trait_method_name) => trait_method_name,
+        }
+    }
+
+    fn get_import_group_message(&self) -> String {
+        match &self.import_candidate {
+            ImportCandidate::UnqualifiedName(name) => format!("Import {}", name),
+            ImportCandidate::QualifierStart(qualifier_start) => {
+                format!("Import {}", qualifier_start)
+            }
+            ImportCandidate::TraitAssocItem(_, trait_assoc_item_name) => {
+                format!("Import a trait for item {}", trait_assoc_item_name)
+            }
+            ImportCandidate::TraitMethod(_, trait_method_name) => {
+                format!("Import a trait for method {}", trait_method_name)
+            }
+        }
+    }
+
+    fn search_for_imports(&self, db: &RootDatabase) -> BTreeSet<ModPath> {
+        let _p = profile("auto_import::search_for_imports");
+        let current_crate = self.module_with_name_to_import.krate();
+        ImportsLocator::new(db)
+            .find_imports(&self.get_search_query())
+            .into_iter()
+            .filter_map(|module_def| match &self.import_candidate {
+                ImportCandidate::TraitAssocItem(assoc_item_type, _) => {
+                    let located_assoc_item = match module_def {
+                        ModuleDef::Function(located_function) => located_function
+                            .as_assoc_item(db)
+                            .map(|assoc| assoc.container(db))
+                            .and_then(Self::assoc_to_trait),
+                        ModuleDef::Const(located_const) => located_const
+                            .as_assoc_item(db)
+                            .map(|assoc| assoc.container(db))
+                            .and_then(Self::assoc_to_trait),
+                        _ => None,
+                    }?;
+
+                    let mut trait_candidates = FxHashSet::default();
+                    trait_candidates.insert(located_assoc_item.into());
+
+                    assoc_item_type
+                        .iterate_path_candidates(
+                            db,
+                            current_crate,
+                            &trait_candidates,
+                            None,
+                            |_, assoc| Self::assoc_to_trait(assoc.container(db)),
+                        )
+                        .map(ModuleDef::from)
+                }
+                ImportCandidate::TraitMethod(function_callee, _) => {
+                    let located_assoc_item =
+                        if let ModuleDef::Function(located_function) = module_def {
+                            located_function
+                                .as_assoc_item(db)
+                                .map(|assoc| assoc.container(db))
+                                .and_then(Self::assoc_to_trait)
+                        } else {
+                            None
+                        }?;
+
+                    let mut trait_candidates = FxHashSet::default();
+                    trait_candidates.insert(located_assoc_item.into());
+
+                    function_callee
+                        .iterate_method_candidates(
+                            db,
+                            current_crate,
+                            &trait_candidates,
+                            None,
+                            |_, function| {
+                                Self::assoc_to_trait(function.as_assoc_item(db)?.container(db))
+                            },
+                        )
+                        .map(ModuleDef::from)
+                }
+                _ => Some(module_def),
+            })
+            .filter_map(|module_def| self.module_with_name_to_import.find_use_path(db, module_def))
+            .filter(|use_path| !use_path.segments.is_empty())
+            .take(20)
+            .collect::<BTreeSet<_>>()
+    }
+
+    fn assoc_to_trait(assoc: AssocItemContainer) -> Option<Trait> {
+        if let AssocItemContainer::Trait(extracted_trait) = assoc {
+            Some(extracted_trait)
+        } else {
+            None
+        }
+    }
+}
+
+#[derive(Debug)]
+enum ImportCandidate {
+    /// Simple name like 'HashMap'
+    UnqualifiedName(String),
+    /// First part of the qualified name.
+    /// For 'std::collections::HashMap', that will be 'std'.
+    QualifierStart(String),
+    /// A trait associated function (with no self parameter) or associated constant.
+    /// For 'test_mod::TestEnum::test_function', `Type` is the `test_mod::TestEnum` expression type
+    /// and `String` is the `test_function`
+    TraitAssocItem(Type, String),
+    /// A trait method with self parameter.
+    /// For 'test_enum.test_method()', `Type` is the `test_enum` expression type
+    /// and `String` is the `test_method`
+    TraitMethod(Type, String),
+}
+
+impl ImportCandidate {
+    fn for_method_call(
+        method_call: &ast::MethodCallExpr,
+        source_analyzer: &SourceAnalyzer,
+        db: &impl HirDatabase,
+    ) -> Option<Self> {
+        if source_analyzer.resolve_method_call(method_call).is_some() {
+            return None;
+        }
+        Some(Self::TraitMethod(
+            source_analyzer.type_of(db, &method_call.expr()?)?,
+            method_call.name_ref()?.syntax().to_string(),
+        ))
+    }
+
+    fn for_regular_path(
+        path_under_caret: &ast::Path,
+        source_analyzer: &SourceAnalyzer,
+        db: &impl HirDatabase,
+    ) -> Option<Self> {
+        if source_analyzer.resolve_path(db, path_under_caret).is_some() {
+            return None;
+        }
+
+        let segment = path_under_caret.segment()?;
+        if let Some(qualifier) = path_under_caret.qualifier() {
+            let qualifier_start = qualifier.syntax().descendants().find_map(ast::NameRef::cast)?;
+            let qualifier_start_path =
+                qualifier_start.syntax().ancestors().find_map(ast::Path::cast)?;
+            if let Some(qualifier_start_resolution) =
+                source_analyzer.resolve_path(db, &qualifier_start_path)
+            {
+                let qualifier_resolution = if qualifier_start_path == qualifier {
+                    qualifier_start_resolution
+                } else {
+                    source_analyzer.resolve_path(db, &qualifier)?
+                };
+                if let PathResolution::Def(ModuleDef::Adt(assoc_item_path)) = qualifier_resolution {
+                    Some(ImportCandidate::TraitAssocItem(
+                        assoc_item_path.ty(db),
+                        segment.syntax().to_string(),
+                    ))
+                } else {
+                    None
+                }
+            } else {
+                Some(ImportCandidate::QualifierStart(qualifier_start.syntax().to_string()))
+            }
+        } else {
+            Some(ImportCandidate::UnqualifiedName(
+                segment.syntax().descendants().find_map(ast::NameRef::cast)?.syntax().to_string(),
+            ))
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
-    use crate::helpers::{check_assist, check_assist_not_applicable, check_assist_target};
-
     use super::*;
+    use crate::helpers::{check_assist, check_assist_not_applicable, check_assist_target};
 
     #[test]
     fn applicable_when_found_an_import() {
@@ -290,4 +491,303 @@ mod tests {
             ",
         );
     }
+
+    #[test]
+    fn not_applicable_for_imported_function() {
+        check_assist_not_applicable(
+            auto_import,
+            r"
+            pub mod test_mod {
+                pub fn test_function() {}
+            }
+
+            use test_mod::test_function;
+            fn main() {
+                test_function<|>
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn associated_struct_function() {
+        check_assist(
+            auto_import,
+            r"
+            mod test_mod {
+                pub struct TestStruct {}
+                impl TestStruct {
+                    pub fn test_function() {}
+                }
+            }
+
+            fn main() {
+                TestStruct::test_function<|>
+            }
+            ",
+            r"
+            use test_mod::TestStruct;
+
+            mod test_mod {
+                pub struct TestStruct {}
+                impl TestStruct {
+                    pub fn test_function() {}
+                }
+            }
+
+            fn main() {
+                TestStruct::test_function<|>
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn associated_struct_const() {
+        check_assist(
+            auto_import,
+            r"
+            mod test_mod {
+                pub struct TestStruct {}
+                impl TestStruct {
+                    const TEST_CONST: u8 = 42;
+                }
+            }
+
+            fn main() {
+                TestStruct::TEST_CONST<|>
+            }
+            ",
+            r"
+            use test_mod::TestStruct;
+
+            mod test_mod {
+                pub struct TestStruct {}
+                impl TestStruct {
+                    const TEST_CONST: u8 = 42;
+                }
+            }
+
+            fn main() {
+                TestStruct::TEST_CONST<|>
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn associated_trait_function() {
+        check_assist(
+            auto_import,
+            r"
+            mod test_mod {
+                pub trait TestTrait {
+                    fn test_function();
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    fn test_function() {}
+                }
+            }
+
+            fn main() {
+                test_mod::TestStruct::test_function<|>
+            }
+            ",
+            r"
+            use test_mod::TestTrait;
+
+            mod test_mod {
+                pub trait TestTrait {
+                    fn test_function();
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    fn test_function() {}
+                }
+            }
+
+            fn main() {
+                test_mod::TestStruct::test_function<|>
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn not_applicable_for_imported_trait_for_function() {
+        check_assist_not_applicable(
+            auto_import,
+            r"
+            mod test_mod {
+                pub trait TestTrait {
+                    fn test_function();
+                }
+                pub trait TestTrait2 {
+                    fn test_function();
+                }
+                pub enum TestEnum {
+                    One,
+                    Two,
+                }
+                impl TestTrait2 for TestEnum {
+                    fn test_function() {}
+                }
+                impl TestTrait for TestEnum {
+                    fn test_function() {}
+                }
+            }
+
+            use test_mod::TestTrait2;
+            fn main() {
+                test_mod::TestEnum::test_function<|>;
+            }
+            ",
+        )
+    }
+
+    #[test]
+    fn associated_trait_const() {
+        check_assist(
+            auto_import,
+            r"
+            mod test_mod {
+                pub trait TestTrait {
+                    const TEST_CONST: u8;
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    const TEST_CONST: u8 = 42;
+                }
+            }
+
+            fn main() {
+                test_mod::TestStruct::TEST_CONST<|>
+            }
+            ",
+            r"
+            use test_mod::TestTrait;
+
+            mod test_mod {
+                pub trait TestTrait {
+                    const TEST_CONST: u8;
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    const TEST_CONST: u8 = 42;
+                }
+            }
+
+            fn main() {
+                test_mod::TestStruct::TEST_CONST<|>
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn not_applicable_for_imported_trait_for_const() {
+        check_assist_not_applicable(
+            auto_import,
+            r"
+            mod test_mod {
+                pub trait TestTrait {
+                    const TEST_CONST: u8;
+                }
+                pub trait TestTrait2 {
+                    const TEST_CONST: f64;
+                }
+                pub enum TestEnum {
+                    One,
+                    Two,
+                }
+                impl TestTrait2 for TestEnum {
+                    const TEST_CONST: f64 = 42.0;
+                }
+                impl TestTrait for TestEnum {
+                    const TEST_CONST: u8 = 42;
+                }
+            }
+
+            use test_mod::TestTrait2;
+            fn main() {
+                test_mod::TestEnum::TEST_CONST<|>;
+            }
+            ",
+        )
+    }
+
+    #[test]
+    fn trait_method() {
+        check_assist(
+            auto_import,
+            r"
+            mod test_mod {
+                pub trait TestTrait {
+                    fn test_method(&self);
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    fn test_method(&self) {}
+                }
+            }
+
+            fn main() {
+                let test_struct = test_mod::TestStruct {};
+                test_struct.test_meth<|>od()
+            }
+            ",
+            r"
+            use test_mod::TestTrait;
+
+            mod test_mod {
+                pub trait TestTrait {
+                    fn test_method(&self);
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    fn test_method(&self) {}
+                }
+            }
+
+            fn main() {
+                let test_struct = test_mod::TestStruct {};
+                test_struct.test_meth<|>od()
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn not_applicable_for_imported_trait_for_method() {
+        check_assist_not_applicable(
+            auto_import,
+            r"
+            mod test_mod {
+                pub trait TestTrait {
+                    fn test_method(&self);
+                }
+                pub trait TestTrait2 {
+                    fn test_method(&self);
+                }
+                pub enum TestEnum {
+                    One,
+                    Two,
+                }
+                impl TestTrait2 for TestEnum {
+                    fn test_method(&self) {}
+                }
+                impl TestTrait for TestEnum {
+                    fn test_method(&self) {}
+                }
+            }
+
+            use test_mod::TestTrait2;
+            fn main() {
+                let one = test_mod::TestEnum::One;
+                one.test<|>_method();
+            }
+            ",
+        )
+    }
 }
diff --git a/crates/ra_assists/src/handlers/fill_match_arms.rs b/crates/ra_assists/src/handlers/fill_match_arms.rs
index 0908fc246..ae2437ed3 100644
--- a/crates/ra_assists/src/handlers/fill_match_arms.rs
+++ b/crates/ra_assists/src/handlers/fill_match_arms.rs
@@ -75,10 +75,10 @@ pub(crate) fn fill_match_arms(ctx: AssistCtx) -> Option<Assist> {
 }
 
 fn is_trivial(arm: &ast::MatchArm) -> bool {
-    arm.pats().any(|pat| match pat {
-        ast::Pat::PlaceholderPat(..) => true,
+    match arm.pat() {
+        Some(ast::Pat::PlaceholderPat(..)) => true,
         _ => false,
-    })
+    }
 }
 
 fn resolve_enum_def(
diff --git a/crates/ra_assists/src/handlers/merge_match_arms.rs b/crates/ra_assists/src/handlers/merge_match_arms.rs
index 670614dd8..b2a194cb5 100644
--- a/crates/ra_assists/src/handlers/merge_match_arms.rs
+++ b/crates/ra_assists/src/handlers/merge_match_arms.rs
@@ -75,7 +75,7 @@ pub(crate) fn merge_match_arms(ctx: AssistCtx) -> Option<Assist> {
         } else {
             arms_to_merge
                 .iter()
-                .flat_map(ast::MatchArm::pats)
+                .filter_map(ast::MatchArm::pat)
                 .map(|x| x.syntax().to_string())
                 .collect::<Vec<String>>()
                 .join(" | ")
@@ -96,10 +96,10 @@ pub(crate) fn merge_match_arms(ctx: AssistCtx) -> Option<Assist> {
 }
 
 fn contains_placeholder(a: &ast::MatchArm) -> bool {
-    a.pats().any(|x| match x {
-        ra_syntax::ast::Pat::PlaceholderPat(..) => true,
+    match a.pat() {
+        Some(ra_syntax::ast::Pat::PlaceholderPat(..)) => true,
         _ => false,
-    })
+    }
 }
 
 fn next_arm(arm: &ast::MatchArm) -> Option<ast::MatchArm> {
diff --git a/crates/ra_assists/src/handlers/move_guard.rs b/crates/ra_assists/src/handlers/move_guard.rs
index 2b91ce7c4..a61a2ba3e 100644
--- a/crates/ra_assists/src/handlers/move_guard.rs
+++ b/crates/ra_assists/src/handlers/move_guard.rs
@@ -90,7 +90,7 @@ pub(crate) fn move_guard_to_arm_body(ctx: AssistCtx) -> Option<Assist> {
 // ```
 pub(crate) fn move_arm_cond_to_match_guard(ctx: AssistCtx) -> Option<Assist> {
     let match_arm: MatchArm = ctx.find_node_at_offset::<MatchArm>()?;
-    let last_match_pat = match_arm.pats().last()?;
+    let match_pat = match_arm.pat()?;
 
     let arm_body = match_arm.expr()?;
     let if_expr: IfExpr = IfExpr::cast(arm_body.syntax().clone())?;
@@ -122,8 +122,8 @@ pub(crate) fn move_arm_cond_to_match_guard(ctx: AssistCtx) -> Option<Assist> {
                 _ => edit.replace(if_expr.syntax().text_range(), then_block.syntax().text()),
             }
 
-            edit.insert(last_match_pat.syntax().text_range().end(), buf);
-            edit.set_cursor(last_match_pat.syntax().text_range().end() + TextUnit::from(1));
+            edit.insert(match_pat.syntax().text_range().end(), buf);
+            edit.set_cursor(match_pat.syntax().text_range().end() + TextUnit::from(1));
         },
     )
 }
diff --git a/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs b/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs
index b70c88ec2..eac452413 100644
--- a/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs
+++ b/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs
@@ -431,7 +431,12 @@ fn best_action_for_target(
                 .find(|n| n.text_range().start() < anchor.text_range().start())
                 .or_else(|| Some(anchor));
 
-            ImportAction::add_new_use(anchor, false)
+            let add_after_anchor = anchor
+                .clone()
+                .and_then(ast::Attr::cast)
+                .map(|attr| attr.kind() == ast::AttrKind::Inner)
+                .unwrap_or(false);
+            ImportAction::add_new_use(anchor, add_after_anchor)
         }
     }
 }
@@ -962,4 +967,26 @@ mod foo {
     ",
         );
     }
+
+    #[test]
+    fn inserts_imports_after_inner_attributes() {
+        check_assist(
+            replace_qualified_name_with_use,
+            "
+#![allow(dead_code)]
+
+fn main() {
+    std::fmt::Debug<|>
+}
+    ",
+            "
+#![allow(dead_code)]
+use std::fmt::Debug;
+
+fn main() {
+    Debug<|>
+}
+    ",
+        );
+    }
 }
diff --git a/crates/ra_cli/Cargo.toml b/crates/ra_cli/Cargo.toml
index bcd408421..53d4876f6 100644
--- a/crates/ra_cli/Cargo.toml
+++ b/crates/ra_cli/Cargo.toml
@@ -6,8 +6,10 @@ authors = ["rust-analyzer developers"]
 publish = false
 
 [dependencies]
+itertools = "0.8.0"
 pico-args = "0.3.0"
 env_logger = { version = "0.7.1", default-features = false }
+rand = { version = "0.7.0", features = ["small_rng"] }
 
 ra_syntax = { path = "../ra_syntax" }
 ra_ide = { path = "../ra_ide" }
diff --git a/crates/ra_cli/src/analysis_bench.rs b/crates/ra_cli/src/analysis_bench.rs
index 5485a38ff..4835a68ce 100644
--- a/crates/ra_cli/src/analysis_bench.rs
+++ b/crates/ra_cli/src/analysis_bench.rs
@@ -2,6 +2,7 @@
 
 use std::{
     path::{Path, PathBuf},
+    str::FromStr,
     sync::Arc,
     time::Instant,
 };
@@ -14,12 +15,35 @@ use ra_ide::{Analysis, AnalysisChange, AnalysisHost, FilePosition, LineCol};
 
 use crate::Result;
 
+pub(crate) struct Position {
+    path: PathBuf,
+    line: u32,
+    column: u32,
+}
+
+impl FromStr for Position {
+    type Err = Box<dyn std::error::Error + Send + Sync>;
+    fn from_str(s: &str) -> Result<Self> {
+        let (path_line, column) = rsplit_at_char(s, ':')?;
+        let (path, line) = rsplit_at_char(path_line, ':')?;
+        Ok(Position { path: path.into(), line: line.parse()?, column: column.parse()? })
+    }
+}
+
+fn rsplit_at_char(s: &str, c: char) -> Result<(&str, &str)> {
+    let idx = s.rfind(':').ok_or_else(|| format!("no `{}` in {}", c, s))?;
+    Ok((&s[..idx], &s[idx + 1..]))
+}
+
 pub(crate) enum Op {
     Highlight { path: PathBuf },
-    Complete { path: PathBuf, line: u32, column: u32 },
+    Complete(Position),
+    GotoDef(Position),
 }
 
 pub(crate) fn run(verbose: bool, path: &Path, op: Op) -> Result<()> {
+    ra_prof::init();
+
     let start = Instant::now();
     eprint!("loading: ");
     let (mut host, roots) = ra_batch::load_cargo(path)?;
@@ -29,7 +53,7 @@ pub(crate) fn run(verbose: bool, path: &Path, op: Op) -> Result<()> {
     let file_id = {
         let path = match &op {
             Op::Highlight { path } => path,
-            Op::Complete { path, .. } => path,
+            Op::Complete(pos) | Op::GotoDef(pos) => &pos.path,
         };
         let path = std::env::current_dir()?.join(path).canonicalize()?;
         roots
@@ -49,7 +73,7 @@ pub(crate) fn run(verbose: bool, path: &Path, op: Op) -> Result<()> {
             .ok_or_else(|| format!("Can't find {:?}", path))?
     };
 
-    match op {
+    match &op {
         Op::Highlight { .. } => {
             let res = do_work(&mut host, file_id, |analysis| {
                 analysis.diagnostics(file_id).unwrap();
@@ -59,16 +83,30 @@ pub(crate) fn run(verbose: bool, path: &Path, op: Op) -> Result<()> {
                 println!("\n{}", res);
             }
         }
-        Op::Complete { line, column, .. } => {
+        Op::Complete(pos) | Op::GotoDef(pos) => {
+            let is_completion = match op {
+                Op::Complete(..) => true,
+                _ => false,
+            };
+
             let offset = host
                 .analysis()
                 .file_line_index(file_id)?
-                .offset(LineCol { line, col_utf16: column });
+                .offset(LineCol { line: pos.line - 1, col_utf16: pos.column });
             let file_postion = FilePosition { file_id, offset };
 
-            let res = do_work(&mut host, file_id, |analysis| analysis.completions(file_postion));
-            if verbose {
-                println!("\n{:#?}", res);
+            if is_completion {
+                let res =
+                    do_work(&mut host, file_id, |analysis| analysis.completions(file_postion));
+                if verbose {
+                    println!("\n{:#?}", res);
+                }
+            } else {
+                let res =
+                    do_work(&mut host, file_id, |analysis| analysis.goto_definition(file_postion));
+                if verbose {
+                    println!("\n{:#?}", res);
+                }
             }
         }
     }
diff --git a/crates/ra_cli/src/analysis_stats.rs b/crates/ra_cli/src/analysis_stats.rs
index 833235bff..6d2dd34c6 100644
--- a/crates/ra_cli/src/analysis_stats.rs
+++ b/crates/ra_cli/src/analysis_stats.rs
@@ -2,6 +2,9 @@
 
 use std::{collections::HashSet, fmt::Write, path::Path, time::Instant};
 
+use itertools::Itertools;
+use rand::{seq::SliceRandom, thread_rng};
+
 use hir::{
     db::{DefDatabase, HirDatabase},
     AssocItem, Crate, HasSource, HirDisplay, ModuleDef,
@@ -19,6 +22,7 @@ pub fn run(
     path: &Path,
     only: Option<&str>,
     with_deps: bool,
+    randomize: bool,
 ) -> Result<()> {
     let db_load_time = Instant::now();
     let (mut host, roots) = ra_batch::load_cargo(path)?;
@@ -41,7 +45,11 @@ pub fn run(
             })
             .collect::<HashSet<_>>();
 
-    for krate in Crate::all(db) {
+    let mut krates = Crate::all(db);
+    if randomize {
+        krates.shuffle(&mut thread_rng());
+    }
+    for krate in krates {
         let module = krate.root_module(db).expect("crate without root module");
         let file_id = module.definition_source(db).file_id;
         if members.contains(&db.file_source_root(file_id.original_file(db))) {
@@ -50,6 +58,10 @@ pub fn run(
         }
     }
 
+    if randomize {
+        visit_queue.shuffle(&mut thread_rng());
+    }
+
     println!("Crates in this dir: {}", num_crates);
     let mut num_decls = 0;
     let mut funcs = Vec::new();
@@ -79,10 +91,14 @@ pub fn run(
     println!("Total functions: {}", funcs.len());
     println!("Item Collection: {:?}, {}", analysis_time.elapsed(), ra_prof::memory_usage());
 
+    if randomize {
+        funcs.shuffle(&mut thread_rng());
+    }
+
     let inference_time = Instant::now();
     let mut bar = match verbosity {
-        Verbosity::Verbose | Verbosity::Normal => ProgressReport::new(funcs.len() as u64),
-        Verbosity::Quiet => ProgressReport::hidden(),
+        Verbosity::Quiet | Verbosity::Spammy => ProgressReport::hidden(),
+        _ => ProgressReport::new(funcs.len() as u64),
     };
 
     bar.tick();
@@ -92,7 +108,20 @@ pub fn run(
     let mut num_type_mismatches = 0;
     for f in funcs {
         let name = f.name(db);
-        let mut msg = format!("processing: {}", name);
+        let full_name = f
+            .module(db)
+            .path_to_root(db)
+            .into_iter()
+            .rev()
+            .filter_map(|it| it.name(db))
+            .chain(Some(f.name(db)))
+            .join("::");
+        if let Some(only_name) = only {
+            if name.to_string() != only_name && full_name != only_name {
+                continue;
+            }
+        }
+        let mut msg = format!("processing: {}", full_name);
         if verbosity.is_verbose() {
             let src = f.source(db);
             let original_file = src.file_id.original_file(db);
@@ -100,15 +129,15 @@ pub fn run(
             let syntax_range = src.value.syntax().text_range();
             write!(msg, " ({:?} {})", path, syntax_range).unwrap();
         }
-        bar.set_message(&msg);
-        if let Some(only_name) = only {
-            if name.to_string() != only_name {
-                continue;
-            }
+        if verbosity.is_spammy() {
+            bar.println(format!("{}", msg));
         }
+        bar.set_message(&msg);
         let f_id = FunctionId::from(f);
         let body = db.body(f_id.into());
         let inference_result = db.infer(f_id.into());
+        let (previous_exprs, previous_unknown, previous_partially_unknown) =
+            (num_exprs, num_exprs_unknown, num_exprs_partially_unknown);
         for (expr_id, _) in body.exprs.iter() {
             let ty = &inference_result[expr_id];
             num_exprs += 1;
@@ -125,6 +154,33 @@ pub fn run(
                     num_exprs_partially_unknown += 1;
                 }
             }
+            if only.is_some() && verbosity.is_spammy() {
+                // in super-verbose mode for just one function, we print every single expression
+                let (_, sm) = db.body_with_source_map(f_id.into());
+                let src = sm.expr_syntax(expr_id);
+                if let Some(src) = src {
+                    let original_file = src.file_id.original_file(db);
+                    let line_index = host.analysis().file_line_index(original_file).unwrap();
+                    let text_range = src.value.either(
+                        |it| it.syntax_node_ptr().range(),
+                        |it| it.syntax_node_ptr().range(),
+                    );
+                    let (start, end) = (
+                        line_index.line_col(text_range.start()),
+                        line_index.line_col(text_range.end()),
+                    );
+                    bar.println(format!(
+                        "{}:{}-{}:{}: {}",
+                        start.line + 1,
+                        start.col_utf16,
+                        end.line + 1,
+                        end.col_utf16,
+                        ty.display(db)
+                    ));
+                } else {
+                    bar.println(format!("unknown location: {}", ty.display(db)));
+                }
+            }
             if let Some(mismatch) = inference_result.type_mismatch_for_expr(expr_id) {
                 num_type_mismatches += 1;
                 if verbosity.is_verbose() {
@@ -164,6 +220,15 @@ pub fn run(
                 }
             }
         }
+        if verbosity.is_spammy() {
+            bar.println(format!(
+                "In {}: {} exprs, {} unknown, {} partial",
+                full_name,
+                num_exprs - previous_exprs,
+                num_exprs_unknown - previous_unknown,
+                num_exprs_partially_unknown - previous_partially_unknown
+            ));
+        }
         bar.inc(1);
     }
     bar.finish_and_clear();
diff --git a/crates/ra_cli/src/main.rs b/crates/ra_cli/src/main.rs
index 806612c2c..750cbab86 100644
--- a/crates/ra_cli/src/main.rs
+++ b/crates/ra_cli/src/main.rs
@@ -16,6 +16,7 @@ type Result<T> = std::result::Result<T, Box<dyn Error + Send + Sync>>;
 
 #[derive(Clone, Copy)]
 pub enum Verbosity {
+    Spammy,
     Verbose,
     Normal,
     Quiet,
@@ -24,7 +25,13 @@ pub enum Verbosity {
 impl Verbosity {
     fn is_verbose(self) -> bool {
         match self {
-            Verbosity::Verbose => true,
+            Verbosity::Verbose | Verbosity::Spammy => true,
+            _ => false,
+        }
+    }
+    fn is_spammy(self) -> bool {
+        match self {
+            Verbosity::Spammy => true,
             _ => false,
         }
     }
@@ -86,14 +93,18 @@ fn main() -> Result<()> {
                 return Ok(());
             }
             let verbosity = match (
+                matches.contains(["-vv", "--spammy"]),
                 matches.contains(["-v", "--verbose"]),
                 matches.contains(["-q", "--quiet"]),
             ) {
-                (false, false) => Verbosity::Normal,
-                (false, true) => Verbosity::Quiet,
-                (true, false) => Verbosity::Verbose,
-                (true, true) => Err("Invalid flags: -q conflicts with -v")?,
+                (true, _, true) => Err("Invalid flags: -q conflicts with -vv")?,
+                (true, _, false) => Verbosity::Spammy,
+                (false, false, false) => Verbosity::Normal,
+                (false, false, true) => Verbosity::Quiet,
+                (false, true, false) => Verbosity::Verbose,
+                (false, true, true) => Err("Invalid flags: -q conflicts with -v")?,
             };
+            let randomize = matches.contains("--randomize");
             let memory_usage = matches.contains("--memory-usage");
             let only: Option<String> = matches.opt_value_from_str(["-o", "--only"])?;
             let with_deps: bool = matches.contains("--with-deps");
@@ -111,6 +122,7 @@ fn main() -> Result<()> {
                 path.as_ref(),
                 only.as_ref().map(String::as_ref),
                 with_deps,
+                randomize,
             )?;
         }
         "analysis-bench" => {
@@ -120,25 +132,16 @@ fn main() -> Result<()> {
             }
             let verbose = matches.contains(["-v", "--verbose"]);
             let path: String = matches.opt_value_from_str("--path")?.unwrap_or_default();
-            let highlight_path = matches.opt_value_from_str("--highlight")?;
-            let complete_path = matches.opt_value_from_str("--complete")?;
-            if highlight_path.is_some() && complete_path.is_some() {
-                panic!("either --highlight or --complete must be set, not both")
-            }
-            let op = if let Some(path) = highlight_path {
-                let path: String = path;
-                analysis_bench::Op::Highlight { path: path.into() }
-            } else if let Some(path_line_col) = complete_path {
-                let path_line_col: String = path_line_col;
-                let (path_line, column) = rsplit_at_char(path_line_col.as_str(), ':')?;
-                let (path, line) = rsplit_at_char(path_line, ':')?;
-                analysis_bench::Op::Complete {
-                    path: path.into(),
-                    line: line.parse()?,
-                    column: column.parse()?,
-                }
-            } else {
-                panic!("either --highlight or --complete must be set")
+            let highlight_path: Option<String> = matches.opt_value_from_str("--highlight")?;
+            let complete_path: Option<String> = matches.opt_value_from_str("--complete")?;
+            let goto_def_path: Option<String> = matches.opt_value_from_str("--goto-def")?;
+            let op = match (highlight_path, complete_path, goto_def_path) {
+                (Some(path), None, None) => analysis_bench::Op::Highlight { path: path.into() },
+                (None, Some(position), None) => analysis_bench::Op::Complete(position.parse()?),
+                (None, None, Some(position)) => analysis_bench::Op::GotoDef(position.parse()?),
+                _ => panic!(
+                    "exactly one of  `--highlight`, `--complete` or `--goto-def` must be set"
+                ),
             };
             matches.finish().or_else(handle_extra_flags)?;
             analysis_bench::run(verbose, path.as_ref(), op)?;
@@ -171,8 +174,3 @@ fn read_stdin() -> Result<String> {
     std::io::stdin().read_to_string(&mut buff)?;
     Ok(buff)
 }
-
-fn rsplit_at_char(s: &str, c: char) -> Result<(&str, &str)> {
-    let idx = s.rfind(':').ok_or_else(|| format!("no `{}` in {}", c, s))?;
-    Ok((&s[..idx], &s[idx + 1..]))
-}
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 4d9641728..a56b8ab04 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -10,9 +10,9 @@ use hir_def::{
     per_ns::PerNs,
     resolver::HasResolver,
     type_ref::{Mutability, TypeRef},
-    AdtId, ConstId, DefWithBodyId, EnumId, FunctionId, GenericDefId, HasModule, ImplId,
-    LocalEnumVariantId, LocalModuleId, LocalStructFieldId, Lookup, ModuleId, StaticId, StructId,
-    TraitId, TypeAliasId, TypeParamId, UnionId,
+    AdtId, AssocContainerId, ConstId, DefWithBodyId, EnumId, FunctionId, GenericDefId, HasModule,
+    ImplId, LocalEnumVariantId, LocalModuleId, LocalStructFieldId, Lookup, ModuleId, StaticId,
+    StructId, TraitId, TypeAliasId, TypeParamId, UnionId,
 };
 use hir_expand::{
     diagnostics::DiagnosticSink,
@@ -25,7 +25,10 @@ use hir_ty::{
 };
 use ra_db::{CrateId, Edition, FileId};
 use ra_prof::profile;
-use ra_syntax::ast::{self, AttrsOwner};
+use ra_syntax::{
+    ast::{self, AttrsOwner},
+    AstNode,
+};
 
 use crate::{
     db::{DefDatabase, HirDatabase},
@@ -119,7 +122,9 @@ impl_froms!(
     BuiltinType
 );
 
-pub use hir_def::{attr::Attrs, item_scope::ItemInNs, visibility::Visibility, AssocItemId};
+pub use hir_def::{
+    attr::Attrs, item_scope::ItemInNs, visibility::Visibility, AssocItemId, AssocItemLoc,
+};
 use rustc_hash::FxHashSet;
 
 impl Module {
@@ -639,17 +644,49 @@ pub struct MacroDef {
     pub(crate) id: MacroDefId,
 }
 
+/// Invariant: `inner.as_assoc_item(db).is_some()`
+/// We do not actively enforce this invariant.
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub enum AssocItem {
     Function(Function),
     Const(Const),
     TypeAlias(TypeAlias),
 }
-// FIXME: not every function, ... is actually an assoc item. maybe we should make
-// sure that you can only turn actual assoc items into AssocItems. This would
-// require not implementing From, and instead having some checked way of
-// casting them, and somehow making the constructors private, which would be annoying.
-impl_froms!(AssocItem: Function, Const, TypeAlias);
+pub enum AssocItemContainer {
+    Trait(Trait),
+    ImplBlock(ImplBlock),
+}
+pub trait AsAssocItem {
+    fn as_assoc_item(self, db: &impl DefDatabase) -> Option<AssocItem>;
+}
+
+impl AsAssocItem for Function {
+    fn as_assoc_item(self, db: &impl DefDatabase) -> Option<AssocItem> {
+        as_assoc_item(db, AssocItem::Function, self.id)
+    }
+}
+impl AsAssocItem for Const {
+    fn as_assoc_item(self, db: &impl DefDatabase) -> Option<AssocItem> {
+        as_assoc_item(db, AssocItem::Const, self.id)
+    }
+}
+impl AsAssocItem for TypeAlias {
+    fn as_assoc_item(self, db: &impl DefDatabase) -> Option<AssocItem> {
+        as_assoc_item(db, AssocItem::TypeAlias, self.id)
+    }
+}
+fn as_assoc_item<ID, DEF, CTOR, AST>(db: &impl DefDatabase, ctor: CTOR, id: ID) -> Option<AssocItem>
+where
+    ID: Lookup<Data = AssocItemLoc<AST>>,
+    DEF: From<ID>,
+    CTOR: FnOnce(DEF) -> AssocItem,
+    AST: AstNode,
+{
+    match id.lookup(db).container {
+        AssocContainerId::TraitId(_) | AssocContainerId::ImplId(_) => Some(ctor(DEF::from(id))),
+        AssocContainerId::ContainerId(_) => None,
+    }
+}
 
 impl AssocItem {
     pub fn module(self, db: &impl DefDatabase) -> Module {
@@ -659,6 +696,18 @@ impl AssocItem {
             AssocItem::TypeAlias(t) => t.module(db),
         }
     }
+    pub fn container(self, db: &impl DefDatabase) -> AssocItemContainer {
+        let container = match self {
+            AssocItem::Function(it) => it.id.lookup(db).container,
+            AssocItem::Const(it) => it.id.lookup(db).container,
+            AssocItem::TypeAlias(it) => it.id.lookup(db).container,
+        };
+        match container {
+            AssocContainerId::TraitId(id) => AssocItemContainer::Trait(id.into()),
+            AssocContainerId::ImplId(id) => AssocItemContainer::ImplBlock(id.into()),
+            AssocContainerId::ContainerId(_) => panic!("invalid AssocItem"),
+        }
+    }
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
@@ -769,6 +818,7 @@ impl TypeParam {
     }
 }
 
+// FIXME: rename from `ImplBlock` to `Impl`
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ImplBlock {
     pub(crate) id: ImplId,
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index e1c7b7a20..5cd965f7a 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -39,10 +39,10 @@ mod has_source;
 
 pub use crate::{
     code_model::{
-        Adt, AssocItem, AttrDef, Const, Crate, CrateDependency, DefWithBody, Docs, Enum,
-        EnumVariant, FieldSource, Function, GenericDef, HasAttrs, HasVisibility, ImplBlock, Local,
-        MacroDef, Module, ModuleDef, ScopeDef, Static, Struct, StructField, Trait, Type, TypeAlias,
-        TypeParam, Union, VariantDef,
+        Adt, AsAssocItem, AssocItem, AssocItemContainer, AttrDef, Const, Crate, CrateDependency,
+        DefWithBody, Docs, Enum, EnumVariant, FieldSource, Function, GenericDef, HasAttrs,
+        HasVisibility, ImplBlock, Local, MacroDef, Module, ModuleDef, ScopeDef, Static, Struct,
+        StructField, Trait, Type, TypeAlias, TypeParam, Union, VariantDef,
     },
     has_source::HasSource,
     source_analyzer::{PathResolution, ScopeEntryWithSyntax, SourceAnalyzer},
diff --git a/crates/ra_hir/src/source_analyzer.rs b/crates/ra_hir/src/source_analyzer.rs
index bb9a35c5d..94d5b4cfd 100644
--- a/crates/ra_hir/src/source_analyzer.rs
+++ b/crates/ra_hir/src/source_analyzer.rs
@@ -15,11 +15,9 @@ use hir_def::{
     },
     expr::{ExprId, PatId},
     resolver::{self, resolver_for_scope, Resolver, TypeNs, ValueNs},
-    DefWithBodyId, TraitId,
-};
-use hir_expand::{
-    hygiene::Hygiene, name::AsName, AstId, HirFileId, InFile, MacroCallId, MacroCallKind,
+    AsMacroCall, DefWithBodyId, TraitId,
 };
+use hir_expand::{hygiene::Hygiene, name::AsName, HirFileId, InFile, MacroCallId};
 use hir_ty::{InEnvironment, InferenceResult, TraitEnvironment};
 use ra_syntax::{
     ast::{self, AstNode},
@@ -363,12 +361,10 @@ impl SourceAnalyzer {
         db: &impl HirDatabase,
         macro_call: InFile<&ast::MacroCall>,
     ) -> Option<Expansion> {
-        let def = self.resolve_macro_call(db, macro_call)?.id;
-        let ast_id = AstId::new(
-            macro_call.file_id,
-            db.ast_id_map(macro_call.file_id).ast_id(macro_call.value),
-        );
-        Some(Expansion { macro_call_id: def.as_call_id(db, MacroCallKind::FnLike(ast_id)) })
+        let macro_call_id = macro_call.as_call_id(db, |path| {
+            self.resolver.resolve_path_as_macro(db, &path).map(|it| it.into())
+        })?;
+        Some(Expansion { macro_call_id })
     }
 }
 
diff --git a/crates/ra_hir_def/Cargo.toml b/crates/ra_hir_def/Cargo.toml
index 1efa00fe0..6b9be9948 100644
--- a/crates/ra_hir_def/Cargo.toml
+++ b/crates/ra_hir_def/Cargo.toml
@@ -14,6 +14,7 @@ rustc-hash = "1.0"
 either = "1.5"
 anymap = "0.12"
 drop_bomb = "0.1.4"
+itertools = "0.8.2"
 
 ra_arena = { path = "../ra_arena" }
 ra_db = { path = "../ra_db" }
diff --git a/crates/ra_hir_def/src/body.rs b/crates/ra_hir_def/src/body.rs
index 142c52d35..010d35e55 100644
--- a/crates/ra_hir_def/src/body.rs
+++ b/crates/ra_hir_def/src/body.rs
@@ -7,9 +7,7 @@ use std::{mem, ops::Index, sync::Arc};
 
 use drop_bomb::DropBomb;
 use either::Either;
-use hir_expand::{
-    ast_id_map::AstIdMap, hygiene::Hygiene, AstId, HirFileId, InFile, MacroCallKind, MacroDefId,
-};
+use hir_expand::{ast_id_map::AstIdMap, hygiene::Hygiene, AstId, HirFileId, InFile, MacroDefId};
 use ra_arena::{map::ArenaMap, Arena};
 use ra_prof::profile;
 use ra_syntax::{ast, AstNode, AstPtr};
@@ -23,7 +21,7 @@ use crate::{
     nameres::CrateDefMap,
     path::{ModPath, Path},
     src::HasSource,
-    DefWithBodyId, HasModule, Lookup, ModuleId,
+    AsMacroCall, DefWithBodyId, HasModule, Lookup, ModuleId,
 };
 
 pub(crate) struct Expander {
@@ -51,30 +49,26 @@ impl Expander {
         db: &DB,
         macro_call: ast::MacroCall,
     ) -> Option<(Mark, T)> {
-        let ast_id = AstId::new(
-            self.current_file_id,
-            db.ast_id_map(self.current_file_id).ast_id(&macro_call),
-        );
-
-        if let Some(path) = macro_call.path().and_then(|path| self.parse_mod_path(path)) {
-            if let Some(def) = self.resolve_path_as_macro(db, &path) {
-                let call_id = def.as_call_id(db, MacroCallKind::FnLike(ast_id));
-                let file_id = call_id.as_file();
-                if let Some(node) = db.parse_or_expand(file_id) {
-                    if let Some(expr) = T::cast(node) {
-                        log::debug!("macro expansion {:#?}", expr.syntax());
-
-                        let mark = Mark {
-                            file_id: self.current_file_id,
-                            ast_id_map: mem::take(&mut self.ast_id_map),
-                            bomb: DropBomb::new("expansion mark dropped"),
-                        };
-                        self.hygiene = Hygiene::new(db, file_id);
-                        self.current_file_id = file_id;
-                        self.ast_id_map = db.ast_id_map(file_id);
-
-                        return Some((mark, expr));
-                    }
+        let macro_call = InFile::new(self.current_file_id, &macro_call);
+
+        if let Some(call_id) =
+            macro_call.as_call_id(db, |path| self.resolve_path_as_macro(db, &path))
+        {
+            let file_id = call_id.as_file();
+            if let Some(node) = db.parse_or_expand(file_id) {
+                if let Some(expr) = T::cast(node) {
+                    log::debug!("macro expansion {:#?}", expr.syntax());
+
+                    let mark = Mark {
+                        file_id: self.current_file_id,
+                        ast_id_map: mem::take(&mut self.ast_id_map),
+                        bomb: DropBomb::new("expansion mark dropped"),
+                    };
+                    self.hygiene = Hygiene::new(db, file_id);
+                    self.current_file_id = file_id;
+                    self.ast_id_map = db.ast_id_map(file_id);
+
+                    return Some((mark, expr));
                 }
             }
         }
@@ -99,10 +93,6 @@ impl Expander {
         Path::from_src(path, &self.hygiene)
     }
 
-    fn parse_mod_path(&mut self, path: ast::Path) -> Option<ModPath> {
-        ModPath::from_src(path, &self.hygiene)
-    }
-
     fn resolve_path_as_macro(&self, db: &impl DefDatabase, path: &ModPath) -> Option<MacroDefId> {
         self.crate_def_map
             .resolve_path(db, self.module.local_id, path, BuiltinShadowMode::Other)
diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index e656f9a41..1fc892362 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -8,7 +8,7 @@ use ra_arena::Arena;
 use ra_syntax::{
     ast::{
         self, ArgListOwner, ArrayExprKind, LiteralKind, LoopBodyOwner, ModuleItemOwner, NameOwner,
-        TypeAscriptionOwner,
+        SlicePatComponents, TypeAscriptionOwner,
     },
     AstNode, AstPtr,
 };
@@ -164,9 +164,9 @@ where
                             let match_expr = self.collect_expr_opt(condition.expr());
                             let placeholder_pat = self.missing_pat();
                             let arms = vec![
-                                MatchArm { pats: vec![pat], expr: then_branch, guard: None },
+                                MatchArm { pat, expr: then_branch, guard: None },
                                 MatchArm {
-                                    pats: vec![placeholder_pat],
+                                    pat: placeholder_pat,
                                     expr: else_branch.unwrap_or_else(|| self.empty_block()),
                                     guard: None,
                                 },
@@ -203,8 +203,8 @@ where
                             let placeholder_pat = self.missing_pat();
                             let break_ = self.alloc_expr_desugared(Expr::Break { expr: None });
                             let arms = vec![
-                                MatchArm { pats: vec![pat], expr: body, guard: None },
-                                MatchArm { pats: vec![placeholder_pat], expr: break_, guard: None },
+                                MatchArm { pat, expr: body, guard: None },
+                                MatchArm { pat: placeholder_pat, expr: break_, guard: None },
                             ];
                             let match_expr =
                                 self.alloc_expr_desugared(Expr::Match { expr: match_expr, arms });
@@ -250,7 +250,7 @@ where
                     match_arm_list
                         .arms()
                         .map(|arm| MatchArm {
-                            pats: arm.pats().map(|p| self.collect_pat(p)).collect(),
+                            pat: self.collect_pat_opt(arm.pat()),
                             expr: self.collect_expr_opt(arm.expr()),
                             guard: arm
                                 .guard()
@@ -587,11 +587,16 @@ where
                 let path = p.path().and_then(|path| self.expander.parse_path(path));
                 path.map(Pat::Path).unwrap_or(Pat::Missing)
             }
+            ast::Pat::OrPat(p) => {
+                let pats = p.pats().map(|p| self.collect_pat(p)).collect();
+                Pat::Or(pats)
+            }
+            ast::Pat::ParenPat(p) => return self.collect_pat_opt(p.pat()),
             ast::Pat::TuplePat(p) => {
                 let args = p.args().map(|p| self.collect_pat(p)).collect();
                 Pat::Tuple(args)
             }
-            ast::Pat::PlaceholderPat(_) => Pat::Wild,
+            ast::Pat::PlaceholderPat(_) | ast::Pat::DotDotPat(_) => Pat::Wild,
             ast::Pat::RecordPat(p) => {
                 let path = p.path().and_then(|path| self.expander.parse_path(path));
                 let record_field_pat_list =
@@ -616,12 +621,20 @@ where
 
                 Pat::Record { path, args: fields }
             }
+            ast::Pat::SlicePat(p) => {
+                let SlicePatComponents { prefix, slice, suffix } = p.components();
+
+                Pat::Slice {
+                    prefix: prefix.into_iter().map(|p| self.collect_pat(p)).collect(),
+                    slice: slice.map(|p| self.collect_pat(p)),
+                    suffix: suffix.into_iter().map(|p| self.collect_pat(p)).collect(),
+                }
+            }
 
             // FIXME: implement
-            ast::Pat::DotDotPat(_) => Pat::Missing,
             ast::Pat::BoxPat(_) => Pat::Missing,
             ast::Pat::LiteralPat(_) => Pat::Missing,
-            ast::Pat::SlicePat(_) | ast::Pat::RangePat(_) => Pat::Missing,
+            ast::Pat::RangePat(_) => Pat::Missing,
         };
         let ptr = AstPtr::new(&pat);
         self.alloc_pat(pattern, Either::Left(ptr))
diff --git a/crates/ra_hir_def/src/body/scope.rs b/crates/ra_hir_def/src/body/scope.rs
index a63552327..a58a7b21f 100644
--- a/crates/ra_hir_def/src/body/scope.rs
+++ b/crates/ra_hir_def/src/body/scope.rs
@@ -158,9 +158,7 @@ fn compute_expr_scopes(expr: ExprId, body: &Body, scopes: &mut ExprScopes, scope
             compute_expr_scopes(*expr, body, scopes, scope);
             for arm in arms {
                 let scope = scopes.new_scope(scope);
-                for pat in &arm.pats {
-                    scopes.add_bindings(body, scope, *pat);
-                }
+                scopes.add_bindings(body, scope, arm.pat);
                 scopes.set_scope(arm.expr, scope);
                 compute_expr_scopes(arm.expr, body, scopes, scope);
             }
@@ -194,7 +192,7 @@ mod tests {
         let (off, code) = extract_offset(code);
         let code = {
             let mut buf = String::new();
-            let off = u32::from(off) as usize;
+            let off = off.to_usize();
             buf.push_str(&code[..off]);
             buf.push_str("marker");
             buf.push_str(&code[off..]);
diff --git a/crates/ra_hir_def/src/expr.rs b/crates/ra_hir_def/src/expr.rs
index a75ef9970..9707c5527 100644
--- a/crates/ra_hir_def/src/expr.rs
+++ b/crates/ra_hir_def/src/expr.rs
@@ -202,7 +202,7 @@ pub enum Array {
 
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct MatchArm {
-    pub pats: Vec<PatId>,
+    pub pat: PatId,
     pub guard: Option<ExprId>,
     pub expr: ExprId,
 }
@@ -382,6 +382,7 @@ pub enum Pat {
     Missing,
     Wild,
     Tuple(Vec<PatId>),
+    Or(Vec<PatId>),
     Record {
         path: Option<Path>,
         args: Vec<RecordFieldPat>,
@@ -393,7 +394,7 @@ pub enum Pat {
     },
     Slice {
         prefix: Vec<PatId>,
-        rest: Option<PatId>,
+        slice: Option<PatId>,
         suffix: Vec<PatId>,
     },
     Path(Path),
@@ -420,12 +421,12 @@ impl Pat {
             Pat::Bind { subpat, .. } => {
                 subpat.iter().copied().for_each(f);
             }
-            Pat::Tuple(args) | Pat::TupleStruct { args, .. } => {
+            Pat::Or(args) | Pat::Tuple(args) | Pat::TupleStruct { args, .. } => {
                 args.iter().copied().for_each(f);
             }
             Pat::Ref { pat, .. } => f(*pat),
-            Pat::Slice { prefix, rest, suffix } => {
-                let total_iter = prefix.iter().chain(rest.iter()).chain(suffix.iter());
+            Pat::Slice { prefix, slice, suffix } => {
+                let total_iter = prefix.iter().chain(slice.iter()).chain(suffix.iter());
                 total_iter.copied().for_each(f);
             }
             Pat::Record { args, .. } => {
diff --git a/crates/ra_hir_def/src/lib.rs b/crates/ra_hir_def/src/lib.rs
index feb3a300d..aa0b558b8 100644
--- a/crates/ra_hir_def/src/lib.rs
+++ b/crates/ra_hir_def/src/lib.rs
@@ -46,7 +46,10 @@ mod marks;
 
 use std::hash::Hash;
 
-use hir_expand::{ast_id_map::FileAstId, AstId, HirFileId, InFile, MacroDefId};
+use hir_expand::{
+    ast_id_map::FileAstId, db::AstDatabase, hygiene::Hygiene, AstId, HirFileId, InFile,
+    MacroCallId, MacroCallKind, MacroDefId,
+};
 use ra_arena::{impl_arena_id, RawId};
 use ra_db::{impl_intern_key, salsa, CrateId};
 use ra_syntax::{ast, AstNode};
@@ -413,3 +416,61 @@ impl HasModule for StaticLoc {
         self.container.module(db)
     }
 }
+
+/// A helper trait for converting to MacroCallId
+pub trait AsMacroCall {
+    fn as_call_id(
+        &self,
+        db: &(impl db::DefDatabase + AstDatabase),
+        resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
+    ) -> Option<MacroCallId>;
+}
+
+impl AsMacroCall for InFile<&ast::MacroCall> {
+    fn as_call_id(
+        &self,
+        db: &(impl db::DefDatabase + AstDatabase),
+        resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
+    ) -> Option<MacroCallId> {
+        let ast_id = AstId::new(self.file_id, db.ast_id_map(self.file_id).ast_id(self.value));
+        let h = Hygiene::new(db, self.file_id);
+        let path = path::ModPath::from_src(self.value.path()?, &h)?;
+
+        AstIdWithPath::new(ast_id.file_id, ast_id.value, path).as_call_id(db, resolver)
+    }
+}
+
+/// Helper wrapper for `AstId` with `ModPath`
+#[derive(Clone, Debug, Eq, PartialEq)]
+struct AstIdWithPath<T: ast::AstNode> {
+    pub ast_id: AstId<T>,
+    pub path: path::ModPath,
+}
+
+impl<T: ast::AstNode> AstIdWithPath<T> {
+    pub fn new(file_id: HirFileId, ast_id: FileAstId<T>, path: path::ModPath) -> AstIdWithPath<T> {
+        AstIdWithPath { ast_id: AstId::new(file_id, ast_id), path }
+    }
+}
+
+impl AsMacroCall for AstIdWithPath<ast::MacroCall> {
+    fn as_call_id(
+        &self,
+        db: &impl AstDatabase,
+        resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
+    ) -> Option<MacroCallId> {
+        let def = resolver(self.path.clone())?;
+        Some(def.as_call_id(db, MacroCallKind::FnLike(self.ast_id.clone())))
+    }
+}
+
+impl AsMacroCall for AstIdWithPath<ast::ModuleItem> {
+    fn as_call_id(
+        &self,
+        db: &impl AstDatabase,
+        resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
+    ) -> Option<MacroCallId> {
+        let def = resolver(self.path.clone())?;
+        Some(def.as_call_id(db, MacroCallKind::Attr(self.ast_id.clone())))
+    }
+}
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index 6352c71ef..51c65a5d7 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -7,7 +7,7 @@ use hir_expand::{
     builtin_derive::find_builtin_derive,
     builtin_macro::find_builtin_macro,
     name::{name, AsName, Name},
-    HirFileId, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
+    HirFileId, MacroCallId, MacroDefId, MacroDefKind,
 };
 use ra_cfg::CfgOptions;
 use ra_db::{CrateId, FileId};
@@ -25,8 +25,9 @@ use crate::{
     path::{ImportAlias, ModPath, PathKind},
     per_ns::PerNs,
     visibility::Visibility,
-    AdtId, AstId, ConstLoc, ContainerId, EnumLoc, EnumVariantId, FunctionLoc, ImplLoc, Intern,
-    LocalModuleId, ModuleDefId, ModuleId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
+    AdtId, AsMacroCall, AstId, AstIdWithPath, ConstLoc, ContainerId, EnumLoc, EnumVariantId,
+    FunctionLoc, ImplLoc, Intern, LocalModuleId, ModuleDefId, ModuleId, StaticLoc, StructLoc,
+    TraitLoc, TypeAliasLoc, UnionLoc,
 };
 
 pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> CrateDefMap {
@@ -99,11 +100,16 @@ struct ImportDirective {
 #[derive(Clone, Debug, Eq, PartialEq)]
 struct MacroDirective {
     module_id: LocalModuleId,
-    ast_id: AstId<ast::MacroCall>,
-    path: ModPath,
+    ast_id: AstIdWithPath<ast::MacroCall>,
     legacy: Option<MacroCallId>,
 }
 
+#[derive(Clone, Debug, Eq, PartialEq)]
+struct DeriveDirective {
+    module_id: LocalModuleId,
+    ast_id: AstIdWithPath<ast::ModuleItem>,
+}
+
 /// Walks the tree of module recursively
 struct DefCollector<'a, DB> {
     db: &'a DB,
@@ -112,7 +118,7 @@ struct DefCollector<'a, DB> {
     unresolved_imports: Vec<ImportDirective>,
     resolved_imports: Vec<ImportDirective>,
     unexpanded_macros: Vec<MacroDirective>,
-    unexpanded_attribute_macros: Vec<(LocalModuleId, AstId<ast::ModuleItem>, ModPath)>,
+    unexpanded_attribute_macros: Vec<DeriveDirective>,
     mod_dirs: FxHashMap<LocalModuleId, ModDir>,
     cfg_options: &'a CfgOptions,
 }
@@ -146,7 +152,7 @@ where
                 ReachedFixedPoint::Yes => break,
                 ReachedFixedPoint::No => i += 1,
             }
-            if i == 1000 {
+            if i == 10000 {
                 log::error!("name resolution is stuck");
                 break;
             }
@@ -515,16 +521,16 @@ where
                 return false;
             }
 
-            let resolved_res = self.def_map.resolve_path_fp_with_macro(
-                self.db,
-                ResolveMode::Other,
-                directive.module_id,
-                &directive.path,
-                BuiltinShadowMode::Module,
-            );
-
-            if let Some(def) = resolved_res.resolved_def.take_macros() {
-                let call_id = def.as_call_id(self.db, MacroCallKind::FnLike(directive.ast_id));
+            if let Some(call_id) = directive.ast_id.as_call_id(self.db, |path| {
+                let resolved_res = self.def_map.resolve_path_fp_with_macro(
+                    self.db,
+                    ResolveMode::Other,
+                    directive.module_id,
+                    &path,
+                    BuiltinShadowMode::Module,
+                );
+                resolved_res.resolved_def.take_macros()
+            }) {
                 resolved.push((directive.module_id, call_id));
                 res = ReachedFixedPoint::No;
                 return false;
@@ -532,12 +538,11 @@ where
 
             true
         });
-        attribute_macros.retain(|(module_id, ast_id, path)| {
-            let resolved_res = self.resolve_attribute_macro(path);
-
-            if let Some(def) = resolved_res {
-                let call_id = def.as_call_id(self.db, MacroCallKind::Attr(*ast_id));
-                resolved.push((*module_id, call_id));
+        attribute_macros.retain(|directive| {
+            if let Some(call_id) =
+                directive.ast_id.as_call_id(self.db, |path| self.resolve_attribute_macro(&path))
+            {
+                resolved.push((directive.module_id, call_id));
                 res = ReachedFixedPoint::No;
                 return false;
             }
@@ -833,20 +838,22 @@ where
                 };
                 let path = ModPath::from_tt_ident(ident);
 
-                let ast_id = AstId::new(self.file_id, def.kind.ast_id());
-                self.def_collector.unexpanded_attribute_macros.push((self.module_id, ast_id, path));
+                let ast_id = AstIdWithPath::new(self.file_id, def.kind.ast_id(), path);
+                self.def_collector
+                    .unexpanded_attribute_macros
+                    .push(DeriveDirective { module_id: self.module_id, ast_id });
             }
         }
     }
 
     fn collect_macro(&mut self, mac: &raw::MacroData) {
-        let ast_id = AstId::new(self.file_id, mac.ast_id);
+        let mut ast_id = AstIdWithPath::new(self.file_id, mac.ast_id, mac.path.clone());
 
         // Case 0: builtin macros
         if mac.builtin {
             if let Some(name) = &mac.name {
                 let krate = self.def_collector.def_map.krate;
-                if let Some(macro_id) = find_builtin_macro(name, krate, ast_id) {
+                if let Some(macro_id) = find_builtin_macro(name, krate, ast_id.ast_id) {
                     self.def_collector.define_macro(
                         self.module_id,
                         name.clone(),
@@ -862,7 +869,7 @@ where
         if is_macro_rules(&mac.path) {
             if let Some(name) = &mac.name {
                 let macro_id = MacroDefId {
-                    ast_id: Some(ast_id),
+                    ast_id: Some(ast_id.ast_id),
                     krate: Some(self.def_collector.def_map.krate),
                     kind: MacroDefKind::Declarative,
                 };
@@ -872,15 +879,13 @@ where
         }
 
         // Case 2: try to resolve in legacy scope and expand macro_rules
-        if let Some(macro_def) = mac.path.as_ident().and_then(|name| {
-            self.def_collector.def_map[self.module_id].scope.get_legacy_macro(&name)
+        if let Some(macro_call_id) = ast_id.as_call_id(self.def_collector.db, |path| {
+            path.as_ident().and_then(|name| {
+                self.def_collector.def_map[self.module_id].scope.get_legacy_macro(&name)
+            })
         }) {
-            let macro_call_id =
-                macro_def.as_call_id(self.def_collector.db, MacroCallKind::FnLike(ast_id));
-
             self.def_collector.unexpanded_macros.push(MacroDirective {
                 module_id: self.module_id,
-                path: mac.path.clone(),
                 ast_id,
                 legacy: Some(macro_call_id),
             });
@@ -890,14 +895,12 @@ where
 
         // Case 3: resolve in module scope, expand during name resolution.
         // We rewrite simple path `macro_name` to `self::macro_name` to force resolve in module scope only.
-        let mut path = mac.path.clone();
-        if path.is_ident() {
-            path.kind = PathKind::Super(0);
+        if ast_id.path.is_ident() {
+            ast_id.path.kind = PathKind::Super(0);
         }
 
         self.def_collector.unexpanded_macros.push(MacroDirective {
             module_id: self.module_id,
-            path,
             ast_id,
             legacy: None,
         });
diff --git a/crates/ra_hir_def/src/resolver.rs b/crates/ra_hir_def/src/resolver.rs
index 05cf4646a..e2b228e80 100644
--- a/crates/ra_hir_def/src/resolver.rs
+++ b/crates/ra_hir_def/src/resolver.rs
@@ -542,11 +542,7 @@ impl Resolver {
 
     fn push_generic_params_scope(self, db: &impl DefDatabase, def: GenericDefId) -> Resolver {
         let params = db.generic_params(def);
-        if params.types.is_empty() {
-            self
-        } else {
-            self.push_scope(Scope::GenericParams { def, params })
-        }
+        self.push_scope(Scope::GenericParams { def, params })
     }
 
     fn push_impl_block_scope(self, impl_block: ImplId) -> Resolver {
diff --git a/crates/ra_hir_expand/src/lib.rs b/crates/ra_hir_expand/src/lib.rs
index 7cf3b59a7..9506f2e1c 100644
--- a/crates/ra_hir_expand/src/lib.rs
+++ b/crates/ra_hir_expand/src/lib.rs
@@ -323,11 +323,18 @@ impl<T: Clone> InFile<&T> {
     }
 }
 
+impl<T> InFile<Option<T>> {
+    pub fn transpose(self) -> Option<InFile<T>> {
+        let value = self.value?;
+        Some(InFile::new(self.file_id, value))
+    }
+}
+
 impl InFile<SyntaxNode> {
-    pub fn ancestors_with_macros<'a>(
+    pub fn ancestors_with_macros(
         self,
-        db: &'a impl crate::db::AstDatabase,
-    ) -> impl Iterator<Item = InFile<SyntaxNode>> + 'a {
+        db: &impl crate::db::AstDatabase,
+    ) -> impl Iterator<Item = InFile<SyntaxNode>> + '_ {
         std::iter::successors(Some(self), move |node| match node.value.parent() {
             Some(parent) => Some(node.with_value(parent)),
             None => {
@@ -338,6 +345,15 @@ impl InFile<SyntaxNode> {
     }
 }
 
+impl InFile<SyntaxToken> {
+    pub fn ancestors_with_macros(
+        self,
+        db: &impl crate::db::AstDatabase,
+    ) -> impl Iterator<Item = InFile<SyntaxNode>> + '_ {
+        self.map(|it| it.parent()).ancestors_with_macros(db)
+    }
+}
+
 impl<N: AstNode> InFile<N> {
     pub fn descendants<T: AstNode>(self) -> impl Iterator<Item = InFile<T>> {
         self.value.syntax().descendants().filter_map(T::cast).map(move |n| self.with_value(n))
diff --git a/crates/ra_hir_ty/src/display.rs b/crates/ra_hir_ty/src/display.rs
index d1ff85f0f..14e089cf4 100644
--- a/crates/ra_hir_ty/src/display.rs
+++ b/crates/ra_hir_ty/src/display.rs
@@ -2,7 +2,12 @@
 
 use std::fmt;
 
-use crate::db::HirDatabase;
+use crate::{
+    db::HirDatabase, utils::generics, ApplicationTy, CallableDef, FnSig, GenericPredicate,
+    Obligation, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
+};
+use hir_def::{generics::TypeParamProvenance, AdtId, AssocContainerId, Lookup};
+use hir_expand::name::Name;
 
 pub struct HirFormatter<'a, 'b, DB> {
     pub db: &'a DB,
@@ -97,3 +102,369 @@ where
         })
     }
 }
+
+const TYPE_HINT_TRUNCATION: &str = "…";
+
+impl HirDisplay for &Ty {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        HirDisplay::hir_fmt(*self, f)
+    }
+}
+
+impl HirDisplay for ApplicationTy {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        if f.should_truncate() {
+            return write!(f, "{}", TYPE_HINT_TRUNCATION);
+        }
+
+        match self.ctor {
+            TypeCtor::Bool => write!(f, "bool")?,
+            TypeCtor::Char => write!(f, "char")?,
+            TypeCtor::Int(t) => write!(f, "{}", t)?,
+            TypeCtor::Float(t) => write!(f, "{}", t)?,
+            TypeCtor::Str => write!(f, "str")?,
+            TypeCtor::Slice => {
+                let t = self.parameters.as_single();
+                write!(f, "[{}]", t.display(f.db))?;
+            }
+            TypeCtor::Array => {
+                let t = self.parameters.as_single();
+                write!(f, "[{}; _]", t.display(f.db))?;
+            }
+            TypeCtor::RawPtr(m) => {
+                let t = self.parameters.as_single();
+                write!(f, "*{}{}", m.as_keyword_for_ptr(), t.display(f.db))?;
+            }
+            TypeCtor::Ref(m) => {
+                let t = self.parameters.as_single();
+                let ty_display = if f.omit_verbose_types() {
+                    t.display_truncated(f.db, f.max_size)
+                } else {
+                    t.display(f.db)
+                };
+                write!(f, "&{}{}", m.as_keyword_for_ref(), ty_display)?;
+            }
+            TypeCtor::Never => write!(f, "!")?,
+            TypeCtor::Tuple { .. } => {
+                let ts = &self.parameters;
+                if ts.len() == 1 {
+                    write!(f, "({},)", ts[0].display(f.db))?;
+                } else {
+                    write!(f, "(")?;
+                    f.write_joined(&*ts.0, ", ")?;
+                    write!(f, ")")?;
+                }
+            }
+            TypeCtor::FnPtr { .. } => {
+                let sig = FnSig::from_fn_ptr_substs(&self.parameters);
+                write!(f, "fn(")?;
+                f.write_joined(sig.params(), ", ")?;
+                write!(f, ") -> {}", sig.ret().display(f.db))?;
+            }
+            TypeCtor::FnDef(def) => {
+                let sig = f.db.callable_item_signature(def).subst(&self.parameters);
+                let name = match def {
+                    CallableDef::FunctionId(ff) => f.db.function_data(ff).name.clone(),
+                    CallableDef::StructId(s) => f.db.struct_data(s).name.clone(),
+                    CallableDef::EnumVariantId(e) => {
+                        let enum_data = f.db.enum_data(e.parent);
+                        enum_data.variants[e.local_id].name.clone()
+                    }
+                };
+                match def {
+                    CallableDef::FunctionId(_) => write!(f, "fn {}", name)?,
+                    CallableDef::StructId(_) | CallableDef::EnumVariantId(_) => {
+                        write!(f, "{}", name)?
+                    }
+                }
+                if self.parameters.len() > 0 {
+                    let generics = generics(f.db, def.into());
+                    let (parent_params, self_param, type_params, _impl_trait_params) =
+                        generics.provenance_split();
+                    let total_len = parent_params + self_param + type_params;
+                    // We print all params except implicit impl Trait params. Still a bit weird; should we leave out parent and self?
+                    if total_len > 0 {
+                        write!(f, "<")?;
+                        f.write_joined(&self.parameters.0[..total_len], ", ")?;
+                        write!(f, ">")?;
+                    }
+                }
+                write!(f, "(")?;
+                f.write_joined(sig.params(), ", ")?;
+                write!(f, ") -> {}", sig.ret().display(f.db))?;
+            }
+            TypeCtor::Adt(def_id) => {
+                let name = match def_id {
+                    AdtId::StructId(it) => f.db.struct_data(it).name.clone(),
+                    AdtId::UnionId(it) => f.db.union_data(it).name.clone(),
+                    AdtId::EnumId(it) => f.db.enum_data(it).name.clone(),
+                };
+                write!(f, "{}", name)?;
+                if self.parameters.len() > 0 {
+                    write!(f, "<")?;
+
+                    let mut non_default_parameters = Vec::with_capacity(self.parameters.len());
+                    let parameters_to_write = if f.omit_verbose_types() {
+                        match self
+                            .ctor
+                            .as_generic_def()
+                            .map(|generic_def_id| f.db.generic_defaults(generic_def_id))
+                            .filter(|defaults| !defaults.is_empty())
+                        {
+                            Option::None => self.parameters.0.as_ref(),
+                            Option::Some(default_parameters) => {
+                                for (i, parameter) in self.parameters.iter().enumerate() {
+                                    match (parameter, default_parameters.get(i)) {
+                                        (&Ty::Unknown, _) | (_, None) => {
+                                            non_default_parameters.push(parameter.clone())
+                                        }
+                                        (_, Some(default_parameter))
+                                            if parameter != default_parameter =>
+                                        {
+                                            non_default_parameters.push(parameter.clone())
+                                        }
+                                        _ => (),
+                                    }
+                                }
+                                &non_default_parameters
+                            }
+                        }
+                    } else {
+                        self.parameters.0.as_ref()
+                    };
+
+                    f.write_joined(parameters_to_write, ", ")?;
+                    write!(f, ">")?;
+                }
+            }
+            TypeCtor::AssociatedType(type_alias) => {
+                let trait_ = match type_alias.lookup(f.db).container {
+                    AssocContainerId::TraitId(it) => it,
+                    _ => panic!("not an associated type"),
+                };
+                let trait_name = f.db.trait_data(trait_).name.clone();
+                let name = f.db.type_alias_data(type_alias).name.clone();
+                write!(f, "{}::{}", trait_name, name)?;
+                if self.parameters.len() > 0 {
+                    write!(f, "<")?;
+                    f.write_joined(&*self.parameters.0, ", ")?;
+                    write!(f, ">")?;
+                }
+            }
+            TypeCtor::Closure { .. } => {
+                let sig = self.parameters[0]
+                    .callable_sig(f.db)
+                    .expect("first closure parameter should contain signature");
+                let return_type_hint = sig.ret().display(f.db);
+                if sig.params().is_empty() {
+                    write!(f, "|| -> {}", return_type_hint)?;
+                } else if f.omit_verbose_types() {
+                    write!(f, "|{}| -> {}", TYPE_HINT_TRUNCATION, return_type_hint)?;
+                } else {
+                    write!(f, "|")?;
+                    f.write_joined(sig.params(), ", ")?;
+                    write!(f, "| -> {}", return_type_hint)?;
+                };
+            }
+        }
+        Ok(())
+    }
+}
+
+impl HirDisplay for ProjectionTy {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        if f.should_truncate() {
+            return write!(f, "{}", TYPE_HINT_TRUNCATION);
+        }
+
+        let trait_name = f.db.trait_data(self.trait_(f.db)).name.clone();
+        write!(f, "<{} as {}", self.parameters[0].display(f.db), trait_name,)?;
+        if self.parameters.len() > 1 {
+            write!(f, "<")?;
+            f.write_joined(&self.parameters[1..], ", ")?;
+            write!(f, ">")?;
+        }
+        write!(f, ">::{}", f.db.type_alias_data(self.associated_ty).name)?;
+        Ok(())
+    }
+}
+
+impl HirDisplay for Ty {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        if f.should_truncate() {
+            return write!(f, "{}", TYPE_HINT_TRUNCATION);
+        }
+
+        match self {
+            Ty::Apply(a_ty) => a_ty.hir_fmt(f)?,
+            Ty::Projection(p_ty) => p_ty.hir_fmt(f)?,
+            Ty::Placeholder(id) => {
+                let generics = generics(f.db, id.parent);
+                let param_data = &generics.params.types[id.local_id];
+                match param_data.provenance {
+                    TypeParamProvenance::TypeParamList | TypeParamProvenance::TraitSelf => {
+                        write!(f, "{}", param_data.name.clone().unwrap_or_else(Name::missing))?
+                    }
+                    TypeParamProvenance::ArgumentImplTrait => {
+                        write!(f, "impl ")?;
+                        let bounds = f.db.generic_predicates_for_param(*id);
+                        let substs = Substs::type_params_for_generics(&generics);
+                        write_bounds_like_dyn_trait(
+                            &bounds.iter().map(|b| b.clone().subst(&substs)).collect::<Vec<_>>(),
+                            f,
+                        )?;
+                    }
+                }
+            }
+            Ty::Bound(idx) => write!(f, "?{}", idx)?,
+            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
+                match self {
+                    Ty::Dyn(_) => write!(f, "dyn ")?,
+                    Ty::Opaque(_) => write!(f, "impl ")?,
+                    _ => unreachable!(),
+                };
+                write_bounds_like_dyn_trait(&predicates, f)?;
+            }
+            Ty::Unknown => write!(f, "{{unknown}}")?,
+            Ty::Infer(..) => write!(f, "_")?,
+        }
+        Ok(())
+    }
+}
+
+fn write_bounds_like_dyn_trait(
+    predicates: &[GenericPredicate],
+    f: &mut HirFormatter<impl HirDatabase>,
+) -> fmt::Result {
+    // Note: This code is written to produce nice results (i.e.
+    // corresponding to surface Rust) for types that can occur in
+    // actual Rust. It will have weird results if the predicates
+    // aren't as expected (i.e. self types = $0, projection
+    // predicates for a certain trait come after the Implemented
+    // predicate for that trait).
+    let mut first = true;
+    let mut angle_open = false;
+    for p in predicates.iter() {
+        match p {
+            GenericPredicate::Implemented(trait_ref) => {
+                if angle_open {
+                    write!(f, ">")?;
+                }
+                if !first {
+                    write!(f, " + ")?;
+                }
+                // We assume that the self type is $0 (i.e. the
+                // existential) here, which is the only thing that's
+                // possible in actual Rust, and hence don't print it
+                write!(f, "{}", f.db.trait_data(trait_ref.trait_).name.clone())?;
+                if trait_ref.substs.len() > 1 {
+                    write!(f, "<")?;
+                    f.write_joined(&trait_ref.substs[1..], ", ")?;
+                    // there might be assoc type bindings, so we leave the angle brackets open
+                    angle_open = true;
+                }
+            }
+            GenericPredicate::Projection(projection_pred) => {
+                // in types in actual Rust, these will always come
+                // after the corresponding Implemented predicate
+                if angle_open {
+                    write!(f, ", ")?;
+                } else {
+                    write!(f, "<")?;
+                    angle_open = true;
+                }
+                let name =
+                    f.db.type_alias_data(projection_pred.projection_ty.associated_ty).name.clone();
+                write!(f, "{} = ", name)?;
+                projection_pred.ty.hir_fmt(f)?;
+            }
+            GenericPredicate::Error => {
+                if angle_open {
+                    // impl Trait<X, {error}>
+                    write!(f, ", ")?;
+                } else if !first {
+                    // impl Trait + {error}
+                    write!(f, " + ")?;
+                }
+                p.hir_fmt(f)?;
+            }
+        }
+        first = false;
+    }
+    if angle_open {
+        write!(f, ">")?;
+    }
+    Ok(())
+}
+
+impl TraitRef {
+    fn hir_fmt_ext(&self, f: &mut HirFormatter<impl HirDatabase>, use_as: bool) -> fmt::Result {
+        if f.should_truncate() {
+            return write!(f, "{}", TYPE_HINT_TRUNCATION);
+        }
+
+        self.substs[0].hir_fmt(f)?;
+        if use_as {
+            write!(f, " as ")?;
+        } else {
+            write!(f, ": ")?;
+        }
+        write!(f, "{}", f.db.trait_data(self.trait_).name.clone())?;
+        if self.substs.len() > 1 {
+            write!(f, "<")?;
+            f.write_joined(&self.substs[1..], ", ")?;
+            write!(f, ">")?;
+        }
+        Ok(())
+    }
+}
+
+impl HirDisplay for TraitRef {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        self.hir_fmt_ext(f, false)
+    }
+}
+
+impl HirDisplay for &GenericPredicate {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        HirDisplay::hir_fmt(*self, f)
+    }
+}
+
+impl HirDisplay for GenericPredicate {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        if f.should_truncate() {
+            return write!(f, "{}", TYPE_HINT_TRUNCATION);
+        }
+
+        match self {
+            GenericPredicate::Implemented(trait_ref) => trait_ref.hir_fmt(f)?,
+            GenericPredicate::Projection(projection_pred) => {
+                write!(f, "<")?;
+                projection_pred.projection_ty.trait_ref(f.db).hir_fmt_ext(f, true)?;
+                write!(
+                    f,
+                    ">::{} = {}",
+                    f.db.type_alias_data(projection_pred.projection_ty.associated_ty).name,
+                    projection_pred.ty.display(f.db)
+                )?;
+            }
+            GenericPredicate::Error => write!(f, "{{error}}")?,
+        }
+        Ok(())
+    }
+}
+
+impl HirDisplay for Obligation {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        match self {
+            Obligation::Trait(tr) => write!(f, "Implements({})", tr.display(f.db)),
+            Obligation::Projection(proj) => write!(
+                f,
+                "Normalize({} => {})",
+                proj.projection_ty.display(f.db),
+                proj.ty.display(f.db)
+            ),
+        }
+    }
+}
diff --git a/crates/ra_hir_ty/src/infer/expr.rs b/crates/ra_hir_ty/src/infer/expr.rs
index 3c9c02d03..39d8bc0ca 100644
--- a/crates/ra_hir_ty/src/infer/expr.rs
+++ b/crates/ra_hir_ty/src/infer/expr.rs
@@ -165,12 +165,14 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             Expr::Match { expr, arms } => {
                 let input_ty = self.infer_expr(*expr, &Expectation::none());
 
-                let mut result_ty = self.table.new_maybe_never_type_var();
+                let mut result_ty = if arms.len() == 0 {
+                    Ty::simple(TypeCtor::Never)
+                } else {
+                    self.table.new_type_var()
+                };
 
                 for arm in arms {
-                    for &pat in &arm.pats {
-                        let _pat_ty = self.infer_pat(pat, &input_ty, BindingMode::default());
-                    }
+                    let _pat_ty = self.infer_pat(arm.pat, &input_ty, BindingMode::default());
                     if let Some(guard_expr) = arm.guard {
                         self.infer_expr(
                             guard_expr,
diff --git a/crates/ra_hir_ty/src/infer/pat.rs b/crates/ra_hir_ty/src/infer/pat.rs
index e7283f24c..a5dfdf6c4 100644
--- a/crates/ra_hir_ty/src/infer/pat.rs
+++ b/crates/ra_hir_ty/src/infer/pat.rs
@@ -82,6 +82,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
         let is_non_ref_pat = match &body[pat] {
             Pat::Tuple(..)
+            | Pat::Or(..)
             | Pat::TupleStruct { .. }
             | Pat::Record { .. }
             | Pat::Range { .. }
@@ -126,6 +127,17 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
                 Ty::apply(TypeCtor::Tuple { cardinality: args.len() as u16 }, Substs(inner_tys))
             }
+            Pat::Or(ref pats) => {
+                if let Some((first_pat, rest)) = pats.split_first() {
+                    let ty = self.infer_pat(*first_pat, expected, default_bm);
+                    for pat in rest {
+                        self.infer_pat(*pat, expected, default_bm);
+                    }
+                    ty
+                } else {
+                    Ty::Unknown
+                }
+            }
             Pat::Ref { pat, mutability } => {
                 let expectation = match expected.as_reference() {
                     Some((inner_ty, exp_mut)) => {
diff --git a/crates/ra_hir_ty/src/infer/unify.rs b/crates/ra_hir_ty/src/infer/unify.rs
index fe05642ae..1dc842f40 100644
--- a/crates/ra_hir_ty/src/infer/unify.rs
+++ b/crates/ra_hir_ty/src/infer/unify.rs
@@ -249,6 +249,8 @@ impl InferenceTable {
         match (ty1, ty2) {
             (Ty::Unknown, _) | (_, Ty::Unknown) => true,
 
+            (Ty::Placeholder(p1), Ty::Placeholder(p2)) if *p1 == *p2 => true,
+
             (Ty::Infer(InferTy::TypeVar(tv1)), Ty::Infer(InferTy::TypeVar(tv2)))
             | (Ty::Infer(InferTy::IntVar(tv1)), Ty::Infer(InferTy::IntVar(tv2)))
             | (Ty::Infer(InferTy::FloatVar(tv1)), Ty::Infer(InferTy::FloatVar(tv2)))
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index c5fe18c85..571579cc4 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -41,13 +41,12 @@ mod marks;
 
 use std::ops::Deref;
 use std::sync::Arc;
-use std::{fmt, iter, mem};
+use std::{iter, mem};
 
 use hir_def::{
-    expr::ExprId, generics::TypeParamProvenance, type_ref::Mutability, AdtId, AssocContainerId,
-    DefWithBodyId, GenericDefId, HasModule, Lookup, TraitId, TypeAliasId, TypeParamId,
+    expr::ExprId, type_ref::Mutability, AdtId, AssocContainerId, DefWithBodyId, GenericDefId,
+    HasModule, Lookup, TraitId, TypeAliasId, TypeParamId,
 };
-use hir_expand::name::Name;
 use ra_db::{impl_intern_key, salsa, CrateId};
 
 use crate::{
@@ -55,7 +54,7 @@ use crate::{
     primitive::{FloatTy, IntTy, Uncertain},
     utils::{generics, make_mut_slice, Generics},
 };
-use display::{HirDisplay, HirFormatter};
+use display::HirDisplay;
 
 pub use autoderef::autoderef;
 pub use infer::{do_infer_query, InferTy, InferenceResult};
@@ -291,7 +290,7 @@ pub enum Ty {
     /// {}` when we're type-checking the body of that function. In this
     /// situation, we know this stands for *some* type, but don't know the exact
     /// type.
-    Param(TypeParamId),
+    Placeholder(TypeParamId),
 
     /// A bound type variable. This is used in various places: when representing
     /// some polymorphic type like the type of function `fn f<T>`, the type
@@ -365,7 +364,7 @@ impl Substs {
 
     /// Return Substs that replace each parameter by itself (i.e. `Ty::Param`).
     pub(crate) fn type_params_for_generics(generic_params: &Generics) -> Substs {
-        Substs(generic_params.iter().map(|(id, _)| Ty::Param(id)).collect())
+        Substs(generic_params.iter().map(|(id, _)| Ty::Placeholder(id)).collect())
     }
 
     /// Return Substs that replace each parameter by itself (i.e. `Ty::Param`).
@@ -813,7 +812,7 @@ impl TypeWalk for Ty {
                     p.walk(f);
                 }
             }
-            Ty::Param { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
+            Ty::Placeholder { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
         }
         f(self);
     }
@@ -831,374 +830,8 @@ impl TypeWalk for Ty {
                     p.walk_mut_binders(f, binders + 1);
                 }
             }
-            Ty::Param { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
+            Ty::Placeholder { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
         }
         f(self, binders);
     }
 }
-
-const TYPE_HINT_TRUNCATION: &str = "…";
-
-impl HirDisplay for &Ty {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        HirDisplay::hir_fmt(*self, f)
-    }
-}
-
-impl HirDisplay for ApplicationTy {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        if f.should_truncate() {
-            return write!(f, "{}", TYPE_HINT_TRUNCATION);
-        }
-
-        match self.ctor {
-            TypeCtor::Bool => write!(f, "bool")?,
-            TypeCtor::Char => write!(f, "char")?,
-            TypeCtor::Int(t) => write!(f, "{}", t)?,
-            TypeCtor::Float(t) => write!(f, "{}", t)?,
-            TypeCtor::Str => write!(f, "str")?,
-            TypeCtor::Slice => {
-                let t = self.parameters.as_single();
-                write!(f, "[{}]", t.display(f.db))?;
-            }
-            TypeCtor::Array => {
-                let t = self.parameters.as_single();
-                write!(f, "[{}; _]", t.display(f.db))?;
-            }
-            TypeCtor::RawPtr(m) => {
-                let t = self.parameters.as_single();
-                write!(f, "*{}{}", m.as_keyword_for_ptr(), t.display(f.db))?;
-            }
-            TypeCtor::Ref(m) => {
-                let t = self.parameters.as_single();
-                let ty_display = if f.omit_verbose_types() {
-                    t.display_truncated(f.db, f.max_size)
-                } else {
-                    t.display(f.db)
-                };
-                write!(f, "&{}{}", m.as_keyword_for_ref(), ty_display)?;
-            }
-            TypeCtor::Never => write!(f, "!")?,
-            TypeCtor::Tuple { .. } => {
-                let ts = &self.parameters;
-                if ts.len() == 1 {
-                    write!(f, "({},)", ts[0].display(f.db))?;
-                } else {
-                    write!(f, "(")?;
-                    f.write_joined(&*ts.0, ", ")?;
-                    write!(f, ")")?;
-                }
-            }
-            TypeCtor::FnPtr { .. } => {
-                let sig = FnSig::from_fn_ptr_substs(&self.parameters);
-                write!(f, "fn(")?;
-                f.write_joined(sig.params(), ", ")?;
-                write!(f, ") -> {}", sig.ret().display(f.db))?;
-            }
-            TypeCtor::FnDef(def) => {
-                let sig = f.db.callable_item_signature(def).subst(&self.parameters);
-                let name = match def {
-                    CallableDef::FunctionId(ff) => f.db.function_data(ff).name.clone(),
-                    CallableDef::StructId(s) => f.db.struct_data(s).name.clone(),
-                    CallableDef::EnumVariantId(e) => {
-                        let enum_data = f.db.enum_data(e.parent);
-                        enum_data.variants[e.local_id].name.clone()
-                    }
-                };
-                match def {
-                    CallableDef::FunctionId(_) => write!(f, "fn {}", name)?,
-                    CallableDef::StructId(_) | CallableDef::EnumVariantId(_) => {
-                        write!(f, "{}", name)?
-                    }
-                }
-                if self.parameters.len() > 0 {
-                    let generics = generics(f.db, def.into());
-                    let (parent_params, self_param, type_params, _impl_trait_params) =
-                        generics.provenance_split();
-                    let total_len = parent_params + self_param + type_params;
-                    // We print all params except implicit impl Trait params. Still a bit weird; should we leave out parent and self?
-                    if total_len > 0 {
-                        write!(f, "<")?;
-                        f.write_joined(&self.parameters.0[..total_len], ", ")?;
-                        write!(f, ">")?;
-                    }
-                }
-                write!(f, "(")?;
-                f.write_joined(sig.params(), ", ")?;
-                write!(f, ") -> {}", sig.ret().display(f.db))?;
-            }
-            TypeCtor::Adt(def_id) => {
-                let name = match def_id {
-                    AdtId::StructId(it) => f.db.struct_data(it).name.clone(),
-                    AdtId::UnionId(it) => f.db.union_data(it).name.clone(),
-                    AdtId::EnumId(it) => f.db.enum_data(it).name.clone(),
-                };
-                write!(f, "{}", name)?;
-                if self.parameters.len() > 0 {
-                    write!(f, "<")?;
-
-                    let mut non_default_parameters = Vec::with_capacity(self.parameters.len());
-                    let parameters_to_write = if f.omit_verbose_types() {
-                        match self
-                            .ctor
-                            .as_generic_def()
-                            .map(|generic_def_id| f.db.generic_defaults(generic_def_id))
-                            .filter(|defaults| !defaults.is_empty())
-                        {
-                            Option::None => self.parameters.0.as_ref(),
-                            Option::Some(default_parameters) => {
-                                for (i, parameter) in self.parameters.iter().enumerate() {
-                                    match (parameter, default_parameters.get(i)) {
-                                        (&Ty::Unknown, _) | (_, None) => {
-                                            non_default_parameters.push(parameter.clone())
-                                        }
-                                        (_, Some(default_parameter))
-                                            if parameter != default_parameter =>
-                                        {
-                                            non_default_parameters.push(parameter.clone())
-                                        }
-                                        _ => (),
-                                    }
-                                }
-                                &non_default_parameters
-                            }
-                        }
-                    } else {
-                        self.parameters.0.as_ref()
-                    };
-
-                    f.write_joined(parameters_to_write, ", ")?;
-                    write!(f, ">")?;
-                }
-            }
-            TypeCtor::AssociatedType(type_alias) => {
-                let trait_ = match type_alias.lookup(f.db).container {
-                    AssocContainerId::TraitId(it) => it,
-                    _ => panic!("not an associated type"),
-                };
-                let trait_name = f.db.trait_data(trait_).name.clone();
-                let name = f.db.type_alias_data(type_alias).name.clone();
-                write!(f, "{}::{}", trait_name, name)?;
-                if self.parameters.len() > 0 {
-                    write!(f, "<")?;
-                    f.write_joined(&*self.parameters.0, ", ")?;
-                    write!(f, ">")?;
-                }
-            }
-            TypeCtor::Closure { .. } => {
-                let sig = self.parameters[0]
-                    .callable_sig(f.db)
-                    .expect("first closure parameter should contain signature");
-                let return_type_hint = sig.ret().display(f.db);
-                if sig.params().is_empty() {
-                    write!(f, "|| -> {}", return_type_hint)?;
-                } else if f.omit_verbose_types() {
-                    write!(f, "|{}| -> {}", TYPE_HINT_TRUNCATION, return_type_hint)?;
-                } else {
-                    write!(f, "|")?;
-                    f.write_joined(sig.params(), ", ")?;
-                    write!(f, "| -> {}", return_type_hint)?;
-                };
-            }
-        }
-        Ok(())
-    }
-}
-
-impl HirDisplay for ProjectionTy {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        if f.should_truncate() {
-            return write!(f, "{}", TYPE_HINT_TRUNCATION);
-        }
-
-        let trait_name = f.db.trait_data(self.trait_(f.db)).name.clone();
-        write!(f, "<{} as {}", self.parameters[0].display(f.db), trait_name,)?;
-        if self.parameters.len() > 1 {
-            write!(f, "<")?;
-            f.write_joined(&self.parameters[1..], ", ")?;
-            write!(f, ">")?;
-        }
-        write!(f, ">::{}", f.db.type_alias_data(self.associated_ty).name)?;
-        Ok(())
-    }
-}
-
-impl HirDisplay for Ty {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        if f.should_truncate() {
-            return write!(f, "{}", TYPE_HINT_TRUNCATION);
-        }
-
-        match self {
-            Ty::Apply(a_ty) => a_ty.hir_fmt(f)?,
-            Ty::Projection(p_ty) => p_ty.hir_fmt(f)?,
-            Ty::Param(id) => {
-                let generics = generics(f.db, id.parent);
-                let param_data = &generics.params.types[id.local_id];
-                match param_data.provenance {
-                    TypeParamProvenance::TypeParamList | TypeParamProvenance::TraitSelf => {
-                        write!(f, "{}", param_data.name.clone().unwrap_or_else(Name::missing))?
-                    }
-                    TypeParamProvenance::ArgumentImplTrait => {
-                        write!(f, "impl ")?;
-                        let bounds = f.db.generic_predicates_for_param(*id);
-                        let substs = Substs::type_params_for_generics(&generics);
-                        write_bounds_like_dyn_trait(
-                            &bounds.iter().map(|b| b.clone().subst(&substs)).collect::<Vec<_>>(),
-                            f,
-                        )?;
-                    }
-                }
-            }
-            Ty::Bound(idx) => write!(f, "?{}", idx)?,
-            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
-                match self {
-                    Ty::Dyn(_) => write!(f, "dyn ")?,
-                    Ty::Opaque(_) => write!(f, "impl ")?,
-                    _ => unreachable!(),
-                };
-                write_bounds_like_dyn_trait(&predicates, f)?;
-            }
-            Ty::Unknown => write!(f, "{{unknown}}")?,
-            Ty::Infer(..) => write!(f, "_")?,
-        }
-        Ok(())
-    }
-}
-
-fn write_bounds_like_dyn_trait(
-    predicates: &[GenericPredicate],
-    f: &mut HirFormatter<impl HirDatabase>,
-) -> fmt::Result {
-    // Note: This code is written to produce nice results (i.e.
-    // corresponding to surface Rust) for types that can occur in
-    // actual Rust. It will have weird results if the predicates
-    // aren't as expected (i.e. self types = $0, projection
-    // predicates for a certain trait come after the Implemented
-    // predicate for that trait).
-    let mut first = true;
-    let mut angle_open = false;
-    for p in predicates.iter() {
-        match p {
-            GenericPredicate::Implemented(trait_ref) => {
-                if angle_open {
-                    write!(f, ">")?;
-                }
-                if !first {
-                    write!(f, " + ")?;
-                }
-                // We assume that the self type is $0 (i.e. the
-                // existential) here, which is the only thing that's
-                // possible in actual Rust, and hence don't print it
-                write!(f, "{}", f.db.trait_data(trait_ref.trait_).name.clone())?;
-                if trait_ref.substs.len() > 1 {
-                    write!(f, "<")?;
-                    f.write_joined(&trait_ref.substs[1..], ", ")?;
-                    // there might be assoc type bindings, so we leave the angle brackets open
-                    angle_open = true;
-                }
-            }
-            GenericPredicate::Projection(projection_pred) => {
-                // in types in actual Rust, these will always come
-                // after the corresponding Implemented predicate
-                if angle_open {
-                    write!(f, ", ")?;
-                } else {
-                    write!(f, "<")?;
-                    angle_open = true;
-                }
-                let name =
-                    f.db.type_alias_data(projection_pred.projection_ty.associated_ty).name.clone();
-                write!(f, "{} = ", name)?;
-                projection_pred.ty.hir_fmt(f)?;
-            }
-            GenericPredicate::Error => {
-                if angle_open {
-                    // impl Trait<X, {error}>
-                    write!(f, ", ")?;
-                } else if !first {
-                    // impl Trait + {error}
-                    write!(f, " + ")?;
-                }
-                p.hir_fmt(f)?;
-            }
-        }
-        first = false;
-    }
-    if angle_open {
-        write!(f, ">")?;
-    }
-    Ok(())
-}
-
-impl TraitRef {
-    fn hir_fmt_ext(&self, f: &mut HirFormatter<impl HirDatabase>, use_as: bool) -> fmt::Result {
-        if f.should_truncate() {
-            return write!(f, "{}", TYPE_HINT_TRUNCATION);
-        }
-
-        self.substs[0].hir_fmt(f)?;
-        if use_as {
-            write!(f, " as ")?;
-        } else {
-            write!(f, ": ")?;
-        }
-        write!(f, "{}", f.db.trait_data(self.trait_).name.clone())?;
-        if self.substs.len() > 1 {
-            write!(f, "<")?;
-            f.write_joined(&self.substs[1..], ", ")?;
-            write!(f, ">")?;
-        }
-        Ok(())
-    }
-}
-
-impl HirDisplay for TraitRef {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        self.hir_fmt_ext(f, false)
-    }
-}
-
-impl HirDisplay for &GenericPredicate {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        HirDisplay::hir_fmt(*self, f)
-    }
-}
-
-impl HirDisplay for GenericPredicate {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        if f.should_truncate() {
-            return write!(f, "{}", TYPE_HINT_TRUNCATION);
-        }
-
-        match self {
-            GenericPredicate::Implemented(trait_ref) => trait_ref.hir_fmt(f)?,
-            GenericPredicate::Projection(projection_pred) => {
-                write!(f, "<")?;
-                projection_pred.projection_ty.trait_ref(f.db).hir_fmt_ext(f, true)?;
-                write!(
-                    f,
-                    ">::{} = {}",
-                    f.db.type_alias_data(projection_pred.projection_ty.associated_ty).name,
-                    projection_pred.ty.display(f.db)
-                )?;
-            }
-            GenericPredicate::Error => write!(f, "{{error}}")?,
-        }
-        Ok(())
-    }
-}
-
-impl HirDisplay for Obligation {
-    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
-        match self {
-            Obligation::Trait(tr) => write!(f, "Implements({})", tr.display(f.db)),
-            Obligation::Projection(proj) => write!(
-                f,
-                "Normalize({} => {})",
-                proj.projection_ty.display(f.db),
-                proj.ty.display(f.db)
-            ),
-        }
-    }
-}
diff --git a/crates/ra_hir_ty/src/lower.rs b/crates/ra_hir_ty/src/lower.rs
index c68c5852b..6a2aded02 100644
--- a/crates/ra_hir_ty/src/lower.rs
+++ b/crates/ra_hir_ty/src/lower.rs
@@ -14,9 +14,9 @@ use hir_def::{
     path::{GenericArg, Path, PathSegment, PathSegments},
     resolver::{HasResolver, Resolver, TypeNs},
     type_ref::{TypeBound, TypeRef},
-    AdtId, ConstId, EnumId, EnumVariantId, FunctionId, GenericDefId, HasModule, ImplId,
-    LocalStructFieldId, Lookup, StaticId, StructId, TraitId, TypeAliasId, TypeParamId, UnionId,
-    VariantId,
+    AdtId, AssocContainerId, ConstId, EnumId, EnumVariantId, FunctionId, GenericDefId, HasModule,
+    ImplId, LocalStructFieldId, Lookup, StaticId, StructId, TraitId, TypeAliasId, TypeParamId,
+    UnionId, VariantId,
 };
 use ra_arena::map::ArenaMap;
 use ra_db::CrateId;
@@ -152,7 +152,7 @@ impl Ty {
                                     data.provenance == TypeParamProvenance::ArgumentImplTrait
                                 })
                                 .nth(idx as usize)
-                                .map_or(Ty::Unknown, |(id, _)| Ty::Param(id));
+                                .map_or(Ty::Unknown, |(id, _)| Ty::Placeholder(id));
                             param
                         } else {
                             Ty::Unknown
@@ -270,7 +270,7 @@ impl Ty {
                 let generics =
                     generics(ctx.db, ctx.resolver.generic_def().expect("generics in scope"));
                 match ctx.type_param_mode {
-                    TypeParamLoweringMode::Placeholder => Ty::Param(param_id),
+                    TypeParamLoweringMode::Placeholder => Ty::Placeholder(param_id),
                     TypeParamLoweringMode::Variable => {
                         let idx = generics.param_idx(param_id).expect("matching generics");
                         Ty::Bound(idx)
@@ -339,7 +339,7 @@ impl Ty {
             None => return Ty::Unknown, // this can't actually happen
         };
         let param_id = match self_ty {
-            Ty::Param(id) if ctx.type_param_mode == TypeParamLoweringMode::Placeholder => id,
+            Ty::Placeholder(id) if ctx.type_param_mode == TypeParamLoweringMode::Placeholder => id,
             Ty::Bound(idx) if ctx.type_param_mode == TypeParamLoweringMode::Variable => {
                 let generics = generics(ctx.db, def);
                 let param_id = if let Some((id, _)) = generics.iter().nth(idx as usize) {
@@ -544,7 +544,7 @@ impl GenericPredicate {
                 let generics = generics(ctx.db, generic_def);
                 let param_id = hir_def::TypeParamId { parent: generic_def, local_id: *param_id };
                 match ctx.type_param_mode {
-                    TypeParamLoweringMode::Placeholder => Ty::Param(param_id),
+                    TypeParamLoweringMode::Placeholder => Ty::Placeholder(param_id),
                     TypeParamLoweringMode::Variable => {
                         let idx = generics.param_idx(param_id).expect("matching generics");
                         Ty::Bound(idx)
@@ -672,11 +672,35 @@ impl TraitEnvironment {
     pub fn lower(db: &impl HirDatabase, resolver: &Resolver) -> Arc<TraitEnvironment> {
         let ctx = TyLoweringContext::new(db, &resolver)
             .with_type_param_mode(TypeParamLoweringMode::Placeholder);
-        let predicates = resolver
+        let mut predicates = resolver
             .where_predicates_in_scope()
             .flat_map(|pred| GenericPredicate::from_where_predicate(&ctx, pred))
             .collect::<Vec<_>>();
 
+        if let Some(def) = resolver.generic_def() {
+            let container: Option<AssocContainerId> = match def {
+                // FIXME: is there a function for this?
+                GenericDefId::FunctionId(f) => Some(f.lookup(db).container),
+                GenericDefId::AdtId(_) => None,
+                GenericDefId::TraitId(_) => None,
+                GenericDefId::TypeAliasId(t) => Some(t.lookup(db).container),
+                GenericDefId::ImplId(_) => None,
+                GenericDefId::EnumVariantId(_) => None,
+                GenericDefId::ConstId(c) => Some(c.lookup(db).container),
+            };
+            if let Some(AssocContainerId::TraitId(trait_id)) = container {
+                // add `Self: Trait<T1, T2, ...>` to the environment in trait
+                // function default implementations (and hypothetical code
+                // inside consts or type aliases)
+                test_utils::tested_by!(trait_self_implements_self);
+                let substs = Substs::type_params(db, trait_id);
+                let trait_ref = TraitRef { trait_: trait_id, substs };
+                let pred = GenericPredicate::Implemented(trait_ref);
+
+                predicates.push(pred);
+            }
+        }
+
         Arc::new(TraitEnvironment { predicates })
     }
 }
diff --git a/crates/ra_hir_ty/src/marks.rs b/crates/ra_hir_ty/src/marks.rs
index 0f754eb9c..de5cb1d6b 100644
--- a/crates/ra_hir_ty/src/marks.rs
+++ b/crates/ra_hir_ty/src/marks.rs
@@ -4,6 +4,8 @@ test_utils::marks!(
     type_var_cycles_resolve_completely
     type_var_cycles_resolve_as_possible
     type_var_resolves_to_int_var
+    impl_self_type_match_without_receiver
     match_ergonomics_ref
     coerce_merge_fail_fallback
+    trait_self_implements_self
 );
diff --git a/crates/ra_hir_ty/src/method_resolution.rs b/crates/ra_hir_ty/src/method_resolution.rs
index 5283bff28..4f8c52433 100644
--- a/crates/ra_hir_ty/src/method_resolution.rs
+++ b/crates/ra_hir_ty/src/method_resolution.rs
@@ -425,6 +425,15 @@ fn iterate_inherent_methods<T>(
                 if !is_valid_candidate(db, name, receiver_ty, item, self_ty) {
                     continue;
                 }
+                // we have to check whether the self type unifies with the type
+                // that the impl is for. If we have a receiver type, this
+                // already happens in `is_valid_candidate` above; if not, we
+                // check it here
+                if receiver_ty.is_none() && inherent_impl_substs(db, impl_block, self_ty).is_none()
+                {
+                    test_utils::tested_by!(impl_self_type_match_without_receiver);
+                    continue;
+                }
                 if let Some(result) = callback(&self_ty.value, item) {
                     return Some(result);
                 }
diff --git a/crates/ra_hir_ty/src/tests/coercion.rs b/crates/ra_hir_ty/src/tests/coercion.rs
index fc5ef36a5..42330b269 100644
--- a/crates/ra_hir_ty/src/tests/coercion.rs
+++ b/crates/ra_hir_ty/src/tests/coercion.rs
@@ -526,3 +526,25 @@ fn test() {
     "###
     );
 }
+
+#[test]
+fn coerce_placeholder_ref() {
+    // placeholders should unify, even behind references
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+struct S<T> { t: T }
+impl<TT> S<TT> {
+    fn get(&self) -> &TT {
+        &self.t
+    }
+}
+"#, true),
+        @r###"
+    [51; 55) 'self': &S<TT>
+    [64; 87) '{     ...     }': &TT
+    [74; 81) '&self.t': &TT
+    [75; 79) 'self': &S<TT>
+    [75; 81) 'self.t': TT
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/method_resolution.rs b/crates/ra_hir_ty/src/tests/method_resolution.rs
index 1722563aa..1f767d324 100644
--- a/crates/ra_hir_ty/src/tests/method_resolution.rs
+++ b/crates/ra_hir_ty/src/tests/method_resolution.rs
@@ -964,6 +964,38 @@ fn test() { S2.into()<|>; }
 }
 
 #[test]
+fn method_resolution_overloaded_method() {
+    test_utils::covers!(impl_self_type_match_without_receiver);
+    let t = type_at(
+        r#"
+//- main.rs
+struct Wrapper<T>(T);
+struct Foo<T>(T);
+struct Bar<T>(T);
+
+impl<T> Wrapper<Foo<T>> {
+    pub fn new(foo_: T) -> Self {
+        Wrapper(Foo(foo_))
+    }
+}
+
+impl<T> Wrapper<Bar<T>> {
+    pub fn new(bar_: T) -> Self {
+        Wrapper(Bar(bar_))
+    }
+}
+
+fn main() {
+    let a = Wrapper::<Foo<f32>>::new(1.0);
+    let b = Wrapper::<Bar<f32>>::new(1.0);
+    (a, b)<|>;
+}
+"#,
+    );
+    assert_eq!(t, "(Wrapper<Foo<f32>>, Wrapper<Bar<f32>>)")
+}
+
+#[test]
 fn method_resolution_encountering_fn_type() {
     type_at(
         r#"
diff --git a/crates/ra_hir_ty/src/tests/never_type.rs b/crates/ra_hir_ty/src/tests/never_type.rs
index c202f545a..a77209480 100644
--- a/crates/ra_hir_ty/src/tests/never_type.rs
+++ b/crates/ra_hir_ty/src/tests/never_type.rs
@@ -101,6 +101,7 @@ fn test() {
     );
     assert_eq!(t, "Option<i32>");
 }
+
 #[test]
 fn never_type_can_be_reinferred3() {
     let t = type_at(
@@ -138,6 +139,22 @@ fn test(a: Void) {
 }
 
 #[test]
+fn match_unknown_arm() {
+    let t = type_at(
+        r#"
+//- /main.rs
+fn test(a: Option) {
+    let t = match 0 {
+        _ => unknown,
+    };
+    t<|>;
+}
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
 fn if_never() {
     let t = type_at(
         r#"
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index 17611ddbf..aa2018944 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -300,6 +300,54 @@ fn test() {
 }
 
 #[test]
+fn trait_default_method_self_bound_implements_trait() {
+    test_utils::covers!(trait_self_implements_self);
+    assert_snapshot!(
+        infer(r#"
+trait Trait {
+    fn foo(&self) -> i64;
+    fn bar(&self) -> {
+        let x = self.foo();
+    }
+}
+"#),
+        @r###"
+    [27; 31) 'self': &Self
+    [53; 57) 'self': &Self
+    [62; 97) '{     ...     }': ()
+    [76; 77) 'x': i64
+    [80; 84) 'self': &Self
+    [80; 90) 'self.foo()': i64
+    "###
+    );
+}
+
+#[test]
+fn trait_default_method_self_bound_implements_super_trait() {
+    test_utils::covers!(trait_self_implements_self);
+    assert_snapshot!(
+        infer(r#"
+trait SuperTrait {
+    fn foo(&self) -> i64;
+}
+trait Trait: SuperTrait {
+    fn bar(&self) -> {
+        let x = self.foo();
+    }
+}
+"#),
+        @r###"
+    [32; 36) 'self': &Self
+    [86; 90) 'self': &Self
+    [95; 130) '{     ...     }': ()
+    [109; 110) 'x': i64
+    [113; 117) 'self': &Self
+    [113; 123) 'self.foo()': i64
+    "###
+    );
+}
+
+#[test]
 fn infer_project_associated_type() {
     // y, z, a don't yet work because of https://github.com/rust-lang/chalk/issues/234
     assert_snapshot!(
diff --git a/crates/ra_hir_ty/src/traits.rs b/crates/ra_hir_ty/src/traits.rs
index 88af61e87..ff8e75b48 100644
--- a/crates/ra_hir_ty/src/traits.rs
+++ b/crates/ra_hir_ty/src/traits.rs
@@ -60,6 +60,9 @@ impl TraitSolver {
                     context.0.db.check_canceled();
                     let remaining = fuel.get();
                     fuel.set(remaining - 1);
+                    if remaining == 0 {
+                        log::debug!("fuel exhausted");
+                    }
                     remaining > 0
                 })
             }
diff --git a/crates/ra_hir_ty/src/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index 4974c565b..882160fa8 100644
--- a/crates/ra_hir_ty/src/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -142,7 +142,7 @@ impl ToChalk for Ty {
                 let substitution = proj_ty.parameters.to_chalk(db);
                 chalk_ir::AliasTy { associated_ty_id, substitution }.cast().intern()
             }
-            Ty::Param(id) => {
+            Ty::Placeholder(id) => {
                 let interned_id = db.intern_type_param_id(id);
                 PlaceholderIndex {
                     ui: UniverseIndex::ROOT,
@@ -184,7 +184,7 @@ impl ToChalk for Ty {
                 let interned_id = crate::db::GlobalTypeParamId::from_intern_id(
                     crate::salsa::InternId::from(idx.idx),
                 );
-                Ty::Param(db.lookup_intern_type_param_id(interned_id))
+                Ty::Placeholder(db.lookup_intern_type_param_id(interned_id))
             }
             chalk_ir::TyData::Alias(proj) => {
                 let associated_ty = from_chalk(db, proj.associated_ty_id);
diff --git a/crates/ra_ide/src/goto_type_definition.rs b/crates/ra_ide/src/goto_type_definition.rs
index 11ad6d137..69940fc36 100644
--- a/crates/ra_ide/src/goto_type_definition.rs
+++ b/crates/ra_ide/src/goto_type_definition.rs
@@ -16,24 +16,16 @@ pub(crate) fn goto_type_definition(
     let token = pick_best(file.token_at_offset(position.offset))?;
     let token = descend_into_macros(db, position.file_id, token);
 
-    let node = token.value.ancestors().find_map(|token| {
-        token
-            .ancestors()
-            .find(|n| ast::Expr::cast(n.clone()).is_some() || ast::Pat::cast(n.clone()).is_some())
-    })?;
+    let node = token
+        .value
+        .ancestors()
+        .find(|n| ast::Expr::cast(n.clone()).is_some() || ast::Pat::cast(n.clone()).is_some())?;
 
     let analyzer = hir::SourceAnalyzer::new(db, token.with_value(&node), None);
 
-    let ty: hir::Type = if let Some(ty) =
-        ast::Expr::cast(node.clone()).and_then(|e| analyzer.type_of(db, &e))
-    {
-        ty
-    } else if let Some(ty) = ast::Pat::cast(node.clone()).and_then(|p| analyzer.type_of_pat(db, &p))
-    {
-        ty
-    } else {
-        return None;
-    };
+    let ty: hir::Type = ast::Expr::cast(node.clone())
+        .and_then(|e| analyzer.type_of(db, &e))
+        .or_else(|| ast::Pat::cast(node.clone()).and_then(|p| analyzer.type_of_pat(db, &p)))?;
 
     let adt_def = ty.autoderef(db).find_map(|ty| ty.as_adt())?;
 
diff --git a/crates/ra_ide/src/inlay_hints.rs b/crates/ra_ide/src/inlay_hints.rs
index 6b0d3d996..2ae97e65f 100644
--- a/crates/ra_ide/src/inlay_hints.rs
+++ b/crates/ra_ide/src/inlay_hints.rs
@@ -80,8 +80,7 @@ fn get_inlay_hints(
             },
             ast::MatchArmList(it) => {
                 it.arms()
-                    .map(|match_arm| match_arm.pats())
-                    .flatten()
+                    .filter_map(|match_arm| match_arm.pat())
                     .for_each(|root_pat| get_pat_type_hints(acc, db, &analyzer, root_pat, true, max_inlay_hint_length));
             },
             ast::CallExpr(it) => {
@@ -202,6 +201,7 @@ fn get_leaf_pats(root_pat: ast::Pat) -> Vec<ast::Pat> {
                 Some(pat) => pats_to_process.push_back(pat),
                 _ => leaf_pats.push(maybe_leaf_pat),
             },
+            ast::Pat::OrPat(ref_pat) => pats_to_process.extend(ref_pat.pats()),
             ast::Pat::TuplePat(tuple_pat) => pats_to_process.extend(tuple_pat.args()),
             ast::Pat::RecordPat(record_pat) => {
                 if let Some(pat_list) = record_pat.record_field_pat_list() {
@@ -222,6 +222,7 @@ fn get_leaf_pats(root_pat: ast::Pat) -> Vec<ast::Pat> {
             ast::Pat::TupleStructPat(tuple_struct_pat) => {
                 pats_to_process.extend(tuple_struct_pat.args())
             }
+            ast::Pat::ParenPat(inner_pat) => pats_to_process.extend(inner_pat.pat()),
             ast::Pat::RefPat(ref_pat) => pats_to_process.extend(ref_pat.pat()),
             _ => (),
         }
diff --git a/crates/ra_ide/src/join_lines.rs b/crates/ra_ide/src/join_lines.rs
index 7deeb3494..01fb32b3d 100644
--- a/crates/ra_ide/src/join_lines.rs
+++ b/crates/ra_ide/src/join_lines.rs
@@ -60,36 +60,15 @@ fn remove_newline(edit: &mut TextEditBuilder, token: &SyntaxToken, offset: TextU
         return;
     }
 
-    // Special case that turns something like:
-    //
-    // ```
-    // my_function({<|>
-    //    <some-expr>
-    // })
-    // ```
-    //
-    // into `my_function(<some-expr>)`
-    if join_single_expr_block(edit, token).is_some() {
-        return;
-    }
-    // ditto for
-    //
-    // ```
-    // use foo::{<|>
-    //    bar
-    // };
-    // ```
-    if join_single_use_tree(edit, token).is_some() {
-        return;
-    }
-
     // The node is between two other nodes
     let prev = token.prev_sibling_or_token().unwrap();
     let next = token.next_sibling_or_token().unwrap();
     if is_trailing_comma(prev.kind(), next.kind()) {
         // Removes: trailing comma, newline (incl. surrounding whitespace)
         edit.delete(TextRange::from_to(prev.text_range().start(), token.text_range().end()));
-    } else if prev.kind() == T![,] && next.kind() == T!['}'] {
+        return;
+    }
+    if prev.kind() == T![,] && next.kind() == T!['}'] {
         // Removes: comma, newline (incl. surrounding whitespace)
         let space = if let Some(left) = prev.prev_sibling_or_token() {
             compute_ws(left.kind(), next.kind())
@@ -100,7 +79,10 @@ fn remove_newline(edit: &mut TextEditBuilder, token: &SyntaxToken, offset: TextU
             TextRange::from_to(prev.text_range().start(), token.text_range().end()),
             space.to_string(),
         );
-    } else if let (Some(_), Some(next)) = (
+        return;
+    }
+
+    if let (Some(_), Some(next)) = (
         prev.as_token().cloned().and_then(ast::Comment::cast),
         next.as_token().cloned().and_then(ast::Comment::cast),
     ) {
@@ -109,10 +91,34 @@ fn remove_newline(edit: &mut TextEditBuilder, token: &SyntaxToken, offset: TextU
             token.text_range().start(),
             next.syntax().text_range().start() + TextUnit::of_str(next.prefix()),
         ));
-    } else {
-        // Remove newline but add a computed amount of whitespace characters
-        edit.replace(token.text_range(), compute_ws(prev.kind(), next.kind()).to_string());
+        return;
+    }
+
+    // Special case that turns something like:
+    //
+    // ```
+    // my_function({<|>
+    //    <some-expr>
+    // })
+    // ```
+    //
+    // into `my_function(<some-expr>)`
+    if join_single_expr_block(edit, token).is_some() {
+        return;
     }
+    // ditto for
+    //
+    // ```
+    // use foo::{<|>
+    //    bar
+    // };
+    // ```
+    if join_single_use_tree(edit, token).is_some() {
+        return;
+    }
+
+    // Remove newline but add a computed amount of whitespace characters
+    edit.replace(token.text_range(), compute_ws(prev.kind(), next.kind()).to_string());
 }
 
 fn has_comma_after(node: &SyntaxNode) -> bool {
@@ -608,4 +614,27 @@ pub fn handle_find_matching_brace() {
 }",
         );
     }
+
+    #[test]
+    fn test_join_lines_commented_block() {
+        check_join_lines(
+            r"
+fn main() {
+    let _ = {
+        // <|>foo
+        // bar
+        92
+    };
+}
+        ",
+            r"
+fn main() {
+    let _ = {
+        // <|>foo bar
+        92
+    };
+}
+        ",
+        )
+    }
 }
diff --git a/crates/ra_ide/src/lib.rs b/crates/ra_ide/src/lib.rs
index 689921f3f..9d66c365b 100644
--- a/crates/ra_ide/src/lib.rs
+++ b/crates/ra_ide/src/lib.rs
@@ -71,7 +71,7 @@ pub use crate::{
     references::{
         Declaration, Reference, ReferenceAccess, ReferenceKind, ReferenceSearchResult, SearchScope,
     },
-    runnables::{Runnable, RunnableKind},
+    runnables::{Runnable, RunnableKind, TestId},
     source_change::{FileSystemEdit, SourceChange, SourceFileEdit},
     syntax_highlighting::HighlightedRange,
 };
diff --git a/crates/ra_ide/src/references.rs b/crates/ra_ide/src/references.rs
index a6320bd2f..de924fad2 100644
--- a/crates/ra_ide/src/references.rs
+++ b/crates/ra_ide/src/references.rs
@@ -13,6 +13,7 @@ mod classify;
 mod rename;
 mod search_scope;
 
+use crate::expand::descend_into_macros_with_analyzer;
 use hir::{InFile, SourceBinder};
 use once_cell::unsync::Lazy;
 use ra_db::{SourceDatabase, SourceDatabaseExt};
@@ -192,39 +193,62 @@ fn process_definition(
 
         let parse = Lazy::new(|| SourceFile::parse(&text));
         let mut sb = Lazy::new(|| SourceBinder::new(db));
+        let mut analyzer = None;
 
         for (idx, _) in text.match_indices(pat) {
             let offset = TextUnit::from_usize(idx);
 
-            if let Some(name_ref) =
+            let (name_ref, range) = if let Some(name_ref) =
                 find_node_at_offset::<ast::NameRef>(parse.tree().syntax(), offset)
             {
                 let range = name_ref.syntax().text_range();
-                if let Some(search_range) = search_range {
-                    if !range.is_subrange(&search_range) {
-                        continue;
-                    }
+                (InFile::new(file_id.into(), name_ref), range)
+            } else {
+                // Handle macro token cases
+                let t = match parse.tree().syntax().token_at_offset(offset) {
+                    TokenAtOffset::None => continue,
+                    TokenAtOffset::Single(t) => t,
+                    TokenAtOffset::Between(_, t) => t,
+                };
+                let range = t.text_range();
+                let analyzer = analyzer.get_or_insert_with(|| {
+                    sb.analyze(InFile::new(file_id.into(), parse.tree().syntax()), None)
+                });
+                let expanded = descend_into_macros_with_analyzer(
+                    db,
+                    &analyzer,
+                    InFile::new(file_id.into(), t),
+                );
+                if let Some(token) = ast::NameRef::cast(expanded.value.parent()) {
+                    (expanded.with_value(token), range)
+                } else {
+                    continue;
                 }
-                // FIXME: reuse sb
-                // See https://github.com/rust-lang/rust/pull/68198#issuecomment-574269098
-
-                if let Some(d) = classify_name_ref(&mut sb, InFile::new(file_id.into(), &name_ref))
-                {
-                    if d == def {
-                        let kind = if is_record_lit_name_ref(&name_ref)
-                            || is_call_expr_name_ref(&name_ref)
-                        {
-                            ReferenceKind::StructLiteral
-                        } else {
-                            ReferenceKind::Other
-                        };
-
-                        refs.push(Reference {
-                            file_range: FileRange { file_id, range },
-                            kind,
-                            access: reference_access(&d.kind, &name_ref),
-                        });
-                    }
+            };
+
+            if let Some(search_range) = search_range {
+                if !range.is_subrange(&search_range) {
+                    continue;
+                }
+            }
+            // FIXME: reuse sb
+            // See https://github.com/rust-lang/rust/pull/68198#issuecomment-574269098
+
+            if let Some(d) = classify_name_ref(&mut sb, name_ref.as_ref()) {
+                if d == def {
+                    let kind = if is_record_lit_name_ref(&name_ref.value)
+                        || is_call_expr_name_ref(&name_ref.value)
+                    {
+                        ReferenceKind::StructLiteral
+                    } else {
+                        ReferenceKind::Other
+                    };
+
+                    refs.push(Reference {
+                        file_range: FileRange { file_id, range },
+                        kind,
+                        access: reference_access(&d.kind, &name_ref.value),
+                    });
                 }
             }
         }
diff --git a/crates/ra_ide/src/references/rename.rs b/crates/ra_ide/src/references/rename.rs
index 08e77c01f..c46b78cb6 100644
--- a/crates/ra_ide/src/references/rename.rs
+++ b/crates/ra_ide/src/references/rename.rs
@@ -211,6 +211,25 @@ mod tests {
     }
 
     #[test]
+    fn test_rename_for_macro_args() {
+        test_rename(
+            r#"
+    macro_rules! foo {($i:ident) => {$i} }
+    fn main() {
+        let a<|> = "test";
+        foo!(a);
+    }"#,
+            "b",
+            r#"
+    macro_rules! foo {($i:ident) => {$i} }
+    fn main() {
+        let b = "test";
+        foo!(b);
+    }"#,
+        );
+    }
+
+    #[test]
     fn test_rename_for_param_inside() {
         test_rename(
             r#"
diff --git a/crates/ra_ide/src/runnables.rs b/crates/ra_ide/src/runnables.rs
index b6b0c70f9..be2a67d0a 100644
--- a/crates/ra_ide/src/runnables.rs
+++ b/crates/ra_ide/src/runnables.rs
@@ -1,6 +1,6 @@
 //! FIXME: write short doc here
 
-use hir::InFile;
+use hir::{InFile, SourceBinder};
 use itertools::Itertools;
 use ra_db::SourceDatabase;
 use ra_ide_db::RootDatabase;
@@ -10,6 +10,7 @@ use ra_syntax::{
 };
 
 use crate::FileId;
+use std::fmt::Display;
 
 #[derive(Debug)]
 pub struct Runnable {
@@ -18,38 +19,84 @@ pub struct Runnable {
 }
 
 #[derive(Debug)]
+pub enum TestId {
+    Name(String),
+    Path(String),
+}
+
+impl Display for TestId {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            TestId::Name(name) => write!(f, "{}", name),
+            TestId::Path(path) => write!(f, "{}", path),
+        }
+    }
+}
+
+#[derive(Debug)]
 pub enum RunnableKind {
-    Test { name: String },
+    Test { test_id: TestId },
     TestMod { path: String },
-    Bench { name: String },
+    Bench { test_id: TestId },
     Bin,
 }
 
 pub(crate) fn runnables(db: &RootDatabase, file_id: FileId) -> Vec<Runnable> {
     let parse = db.parse(file_id);
-    parse.tree().syntax().descendants().filter_map(|i| runnable(db, file_id, i)).collect()
+    let mut sb = SourceBinder::new(db);
+    parse.tree().syntax().descendants().filter_map(|i| runnable(db, &mut sb, file_id, i)).collect()
 }
 
-fn runnable(db: &RootDatabase, file_id: FileId, item: SyntaxNode) -> Option<Runnable> {
+fn runnable(
+    db: &RootDatabase,
+    source_binder: &mut SourceBinder<RootDatabase>,
+    file_id: FileId,
+    item: SyntaxNode,
+) -> Option<Runnable> {
     match_ast! {
         match item {
-            ast::FnDef(it) => { runnable_fn(it) },
-            ast::Module(it) => { runnable_mod(db, file_id, it) },
+            ast::FnDef(it) => { runnable_fn(db, source_binder, file_id, it) },
+            ast::Module(it) => { runnable_mod(db, source_binder, file_id, it) },
             _ => { None },
         }
     }
 }
 
-fn runnable_fn(fn_def: ast::FnDef) -> Option<Runnable> {
-    let name = fn_def.name()?.text().clone();
-    let kind = if name == "main" {
+fn runnable_fn(
+    db: &RootDatabase,
+    source_binder: &mut SourceBinder<RootDatabase>,
+    file_id: FileId,
+    fn_def: ast::FnDef,
+) -> Option<Runnable> {
+    let name_string = fn_def.name()?.text().to_string();
+
+    let kind = if name_string == "main" {
         RunnableKind::Bin
-    } else if has_test_related_attribute(&fn_def) {
-        RunnableKind::Test { name: name.to_string() }
-    } else if fn_def.has_atom_attr("bench") {
-        RunnableKind::Bench { name: name.to_string() }
     } else {
-        return None;
+        let test_id = if let Some(module) = source_binder
+            .to_def(InFile::new(file_id.into(), fn_def.clone()))
+            .map(|def| def.module(db))
+        {
+            let path = module
+                .path_to_root(db)
+                .into_iter()
+                .rev()
+                .filter_map(|it| it.name(db))
+                .map(|name| name.to_string())
+                .chain(std::iter::once(name_string))
+                .join("::");
+            TestId::Path(path)
+        } else {
+            TestId::Name(name_string)
+        };
+
+        if has_test_related_attribute(&fn_def) {
+            RunnableKind::Test { test_id }
+        } else if fn_def.has_atom_attr("bench") {
+            RunnableKind::Bench { test_id }
+        } else {
+            return None;
+        }
     };
     Some(Runnable { range: fn_def.syntax().text_range(), kind })
 }
@@ -68,7 +115,12 @@ fn has_test_related_attribute(fn_def: &ast::FnDef) -> bool {
         .any(|attribute_text| attribute_text.contains("test"))
 }
 
-fn runnable_mod(db: &RootDatabase, file_id: FileId, module: ast::Module) -> Option<Runnable> {
+fn runnable_mod(
+    db: &RootDatabase,
+    source_binder: &mut SourceBinder<RootDatabase>,
+    file_id: FileId,
+    module: ast::Module,
+) -> Option<Runnable> {
     let has_test_function = module
         .item_list()?
         .items()
@@ -76,13 +128,12 @@ fn runnable_mod(db: &RootDatabase, file_id: FileId, module: ast::Module) -> Opti
             ast::ModuleItem::FnDef(it) => Some(it),
             _ => None,
         })
-        .any(|f| f.has_atom_attr("test"));
+        .any(|f| has_test_related_attribute(&f));
     if !has_test_function {
         return None;
     }
     let range = module.syntax().text_range();
-    let mut sb = hir::SourceBinder::new(db);
-    let module = sb.to_def(InFile::new(file_id.into(), module))?;
+    let module = source_binder.to_def(InFile::new(file_id.into(), module))?;
 
     let path = module.path_to_root(db).into_iter().rev().filter_map(|it| it.name(db)).join("::");
     Some(Runnable { range, kind: RunnableKind::TestMod { path } })
@@ -121,13 +172,17 @@ mod tests {
             Runnable {
                 range: [22; 46),
                 kind: Test {
-                    name: "test_foo",
+                    test_id: Path(
+                        "test_foo",
+                    ),
                 },
             },
             Runnable {
                 range: [47; 81),
                 kind: Test {
-                    name: "test_foo",
+                    test_id: Path(
+                        "test_foo",
+                    ),
                 },
             },
         ]
@@ -160,7 +215,9 @@ mod tests {
             Runnable {
                 range: [28; 57),
                 kind: Test {
-                    name: "test_foo1",
+                    test_id: Path(
+                        "test_mod::test_foo1",
+                    ),
                 },
             },
         ]
@@ -195,7 +252,9 @@ mod tests {
             Runnable {
                 range: [46; 79),
                 kind: Test {
-                    name: "test_foo1",
+                    test_id: Path(
+                        "foo::test_mod::test_foo1",
+                    ),
                 },
             },
         ]
@@ -232,7 +291,9 @@ mod tests {
             Runnable {
                 range: [68; 105),
                 kind: Test {
-                    name: "test_foo1",
+                    test_id: Path(
+                        "foo::bar::test_mod::test_foo1",
+                    ),
                 },
             },
         ]
diff --git a/crates/ra_ide/src/snapshots/highlighting.html b/crates/ra_ide/src/snapshots/highlighting.html
index 1cc55e78b..a02dbaf2f 100644
--- a/crates/ra_ide/src/snapshots/highlighting.html
+++ b/crates/ra_ide/src/snapshots/highlighting.html
@@ -16,6 +16,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .literal            { color: #BFEBBF; }
 .literal\.numeric  { color: #6A8759; }
 .macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
 .variable           { color: #DCDCCC; }
 .variable\.mut     { color: #DCDCCC; text-decoration: underline; }
 
diff --git a/crates/ra_ide/src/snapshots/rainbow_highlighting.html b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
index 918fd4b97..95f038f00 100644
--- a/crates/ra_ide/src/snapshots/rainbow_highlighting.html
+++ b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
@@ -16,6 +16,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .literal            { color: #BFEBBF; }
 .literal\.numeric  { color: #6A8759; }
 .macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
 .variable           { color: #DCDCCC; }
 .variable\.mut     { color: #DCDCCC; text-decoration: underline; }
 
diff --git a/crates/ra_ide/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index 174e13595..20c414ca1 100644
--- a/crates/ra_ide/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -365,6 +365,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .literal            { color: #BFEBBF; }
 .literal\\.numeric  { color: #6A8759; }
 .macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
 .variable           { color: #DCDCCC; }
 .variable\\.mut     { color: #DCDCCC; text-decoration: underline; }
 
diff --git a/crates/ra_ide_db/Cargo.toml b/crates/ra_ide_db/Cargo.toml
index 716e88bc1..495fffb5a 100644
--- a/crates/ra_ide_db/Cargo.toml
+++ b/crates/ra_ide_db/Cargo.toml
@@ -22,7 +22,6 @@ fst = { version = "0.3.1", default-features = false }
 rustc-hash = "1.0"
 unicase = "2.2.0"
 superslice = "1.0.0"
-rand = { version = "0.7.0", features = ["small_rng"] }
 once_cell = "1.2.0"
 
 ra_syntax = { path = "../ra_syntax" }
diff --git a/crates/ra_lsp_server/src/cargo_target_spec.rs b/crates/ra_lsp_server/src/cargo_target_spec.rs
index 594caffe2..5fd1e7b6b 100644
--- a/crates/ra_lsp_server/src/cargo_target_spec.rs
+++ b/crates/ra_lsp_server/src/cargo_target_spec.rs
@@ -1,6 +1,6 @@
 //! FIXME: write short doc here
 
-use ra_ide::{FileId, RunnableKind};
+use ra_ide::{FileId, RunnableKind, TestId};
 use ra_project_model::{self, ProjectWorkspace, TargetKind};
 
 use crate::{world::WorldSnapshot, Result};
@@ -13,13 +13,16 @@ pub(crate) fn runnable_args(
     let spec = CargoTargetSpec::for_file(world, file_id)?;
     let mut res = Vec::new();
     match kind {
-        RunnableKind::Test { name } => {
+        RunnableKind::Test { test_id } => {
             res.push("test".to_string());
             if let Some(spec) = spec {
                 spec.push_to(&mut res);
             }
             res.push("--".to_string());
-            res.push(name.to_string());
+            res.push(test_id.to_string());
+            if let TestId::Path(_) = test_id {
+                res.push("--exact".to_string());
+            }
             res.push("--nocapture".to_string());
         }
         RunnableKind::TestMod { path } => {
@@ -31,13 +34,16 @@ pub(crate) fn runnable_args(
             res.push(path.to_string());
             res.push("--nocapture".to_string());
         }
-        RunnableKind::Bench { name } => {
+        RunnableKind::Bench { test_id } => {
             res.push("bench".to_string());
             if let Some(spec) = spec {
                 spec.push_to(&mut res);
             }
             res.push("--".to_string());
-            res.push(name.to_string());
+            res.push(test_id.to_string());
+            if let TestId::Path(_) = test_id {
+                res.push("--exact".to_string());
+            }
             res.push("--nocapture".to_string());
         }
         RunnableKind::Bin => {
diff --git a/crates/ra_lsp_server/src/config.rs b/crates/ra_lsp_server/src/config.rs
index 2d7948d74..3314269ec 100644
--- a/crates/ra_lsp_server/src/config.rs
+++ b/crates/ra_lsp_server/src/config.rs
@@ -44,6 +44,8 @@ pub struct ServerConfig {
     /// Fine grained feature flags to disable specific features.
     pub feature_flags: FxHashMap<String, bool>,
 
+    pub rustfmt_args: Vec<String>,
+
     /// Cargo feature configurations.
     pub cargo_features: CargoFeatures,
 }
@@ -63,6 +65,7 @@ impl Default for ServerConfig {
             with_sysroot: true,
             feature_flags: FxHashMap::default(),
             cargo_features: Default::default(),
+            rustfmt_args: Vec::new(),
         }
     }
 }
diff --git a/crates/ra_lsp_server/src/lib.rs b/crates/ra_lsp_server/src/lib.rs
index 1208c1343..a3464a5a3 100644
--- a/crates/ra_lsp_server/src/lib.rs
+++ b/crates/ra_lsp_server/src/lib.rs
@@ -31,6 +31,8 @@ mod config;
 mod world;
 mod diagnostics;
 
+use serde::de::DeserializeOwned;
+
 pub type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;
 pub use crate::{
     caps::server_capabilities,
@@ -38,3 +40,9 @@ pub use crate::{
     main_loop::LspError,
     main_loop::{main_loop, show_message},
 };
+
+pub fn from_json<T: DeserializeOwned>(what: &'static str, json: serde_json::Value) -> Result<T> {
+    let res = T::deserialize(&json)
+        .map_err(|e| format!("Failed to deserialize {}: {}; {}", what, e, json))?;
+    Ok(res)
+}
diff --git a/crates/ra_lsp_server/src/main.rs b/crates/ra_lsp_server/src/main.rs
index 3879eeff2..ed2eaabd4 100644
--- a/crates/ra_lsp_server/src/main.rs
+++ b/crates/ra_lsp_server/src/main.rs
@@ -1,7 +1,7 @@
 //! `ra_lsp_server` binary
 
 use lsp_server::Connection;
-use ra_lsp_server::{show_message, Result, ServerConfig};
+use ra_lsp_server::{from_json, show_message, Result, ServerConfig};
 use ra_prof;
 
 fn main() -> Result<()> {
@@ -15,13 +15,8 @@ fn main() -> Result<()> {
 
 fn setup_logging() -> Result<()> {
     std::env::set_var("RUST_BACKTRACE", "short");
-
     env_logger::try_init()?;
-
-    ra_prof::set_filter(match std::env::var("RA_PROFILE") {
-        Ok(spec) => ra_prof::Filter::from_spec(&spec),
-        Err(_) => ra_prof::Filter::disabled(),
-    });
+    ra_prof::init();
     Ok(())
 }
 
@@ -45,7 +40,8 @@ fn run_server() -> Result<()> {
     let server_capabilities = serde_json::to_value(ra_lsp_server::server_capabilities()).unwrap();
 
     let initialize_params = connection.initialize(server_capabilities)?;
-    let initialize_params: lsp_types::InitializeParams = serde_json::from_value(initialize_params)?;
+    let initialize_params =
+        from_json::<lsp_types::InitializeParams>("InitializeParams", initialize_params)?;
 
     if let Some(client_info) = initialize_params.client_info {
         log::info!("Client '{}' {}", client_info.name, client_info.version.unwrap_or_default());
@@ -62,17 +58,13 @@ fn run_server() -> Result<()> {
         .filter(|workspaces| !workspaces.is_empty())
         .unwrap_or_else(|| vec![root]);
 
-    let server_config: ServerConfig = initialize_params
+    let server_config = initialize_params
         .initialization_options
         .and_then(|v| {
-            serde_json::from_value(v)
+            from_json::<ServerConfig>("config", v)
                 .map_err(|e| {
-                    log::error!("failed to deserialize config: {}", e);
-                    show_message(
-                        lsp_types::MessageType::Error,
-                        format!("failed to deserialize config: {}", e),
-                        &connection.sender,
-                    );
+                    log::error!("{}", e);
+                    show_message(lsp_types::MessageType::Error, e.to_string(), &connection.sender);
                 })
                 .ok()
         })
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index ceff82fda..1e70cea13 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -178,6 +178,7 @@ pub fn main_loop(
                     command: config.cargo_watch_command,
                     all_targets: config.cargo_watch_all_targets,
                 },
+                rustfmt_args: config.rustfmt_args,
             }
         };
 
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index 65e8bc856..3893430c0 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -35,6 +35,7 @@ use crate::{
         TryConvWithToVec,
     },
     diagnostics::DiagnosticTask,
+    from_json,
     req::{self, Decoration, InlayHint, InlayHintsParams, InlayKind},
     world::WorldSnapshot,
     LspError, Result,
@@ -589,6 +590,7 @@ pub fn handle_formatting(
     let end_position = TextUnit::of_str(&file).conv_with(&file_line_index);
 
     let mut rustfmt = process::Command::new("rustfmt");
+    rustfmt.args(&world.options.rustfmt_args);
     if let Some(&crate_id) = crate_ids.first() {
         // Assume all crates are in the same edition
         let edition = world.analysis().crate_edition(crate_id)?;
@@ -757,7 +759,7 @@ pub fn handle_code_lens(
     // Gather runnables
     for runnable in world.analysis().runnables(file_id)? {
         let title = match &runnable.kind {
-            RunnableKind::Test { .. } | RunnableKind::TestMod { .. } => "▶️Run Test",
+            RunnableKind::Test { .. } | RunnableKind::TestMod { .. } => "▶️\u{fe0e}Run Test",
             RunnableKind::Bench { .. } => "Run Bench",
             RunnableKind::Bin => "Run",
         }
@@ -811,7 +813,7 @@ enum CodeLensResolveData {
 pub fn handle_code_lens_resolve(world: WorldSnapshot, code_lens: CodeLens) -> Result<CodeLens> {
     let _p = profile("handle_code_lens_resolve");
     let data = code_lens.data.unwrap();
-    let resolve = serde_json::from_value(data)?;
+    let resolve = from_json::<Option<CodeLensResolveData>>("CodeLensResolveData", data)?;
     match resolve {
         Some(CodeLensResolveData::Impls(lens_params)) => {
             let locations: Vec<Location> =
@@ -917,9 +919,9 @@ fn to_lsp_runnable(
     let args = runnable_args(world, file_id, &runnable.kind)?;
     let line_index = world.analysis().file_line_index(file_id)?;
     let label = match &runnable.kind {
-        RunnableKind::Test { name } => format!("test {}", name),
+        RunnableKind::Test { test_id } => format!("test {}", test_id),
         RunnableKind::TestMod { path } => format!("test-mod {}", path),
-        RunnableKind::Bench { name } => format!("bench {}", name),
+        RunnableKind::Bench { test_id } => format!("bench {}", test_id),
         RunnableKind::Bin => "run binary".to_string(),
     };
     Ok(req::Runnable {
diff --git a/crates/ra_lsp_server/src/world.rs b/crates/ra_lsp_server/src/world.rs
index 1ee02b47c..d993c5fc4 100644
--- a/crates/ra_lsp_server/src/world.rs
+++ b/crates/ra_lsp_server/src/world.rs
@@ -34,6 +34,7 @@ pub struct Options {
     pub supports_location_link: bool,
     pub line_folding_only: bool,
     pub max_inlay_hint_length: Option<usize>,
+    pub rustfmt_args: Vec<String>,
     pub cargo_watch: CheckOptions,
 }
 
diff --git a/crates/ra_lsp_server/tests/heavy_tests/main.rs b/crates/ra_lsp_server/tests/heavy_tests/main.rs
index dff63a12d..9ca31cbcc 100644
--- a/crates/ra_lsp_server/tests/heavy_tests/main.rs
+++ b/crates/ra_lsp_server/tests/heavy_tests/main.rs
@@ -147,7 +147,7 @@ fn main() {}
         },
         json!([
           {
-            "args": [ "test", "--package", "foo", "--test", "spam", "--", "test_eggs", "--nocapture" ],
+            "args": [ "test", "--package", "foo", "--test", "spam", "--", "test_eggs", "--exact", "--nocapture" ],
             "bin": "cargo",
             "env": { "RUST_BACKTRACE": "short" },
             "label": "test test_eggs",
diff --git a/crates/ra_parser/src/grammar/expressions/atom.rs b/crates/ra_parser/src/grammar/expressions/atom.rs
index f154077a8..b72d2e9e6 100644
--- a/crates/ra_parser/src/grammar/expressions/atom.rs
+++ b/crates/ra_parser/src/grammar/expressions/atom.rs
@@ -336,7 +336,7 @@ fn for_expr(p: &mut Parser, m: Option<Marker>) -> CompletedMarker {
 fn cond(p: &mut Parser) {
     let m = p.start();
     if p.eat(T![let]) {
-        patterns::pattern_list(p);
+        patterns::pattern_top(p);
         p.expect(T![=]);
     }
     expr_no_struct(p);
@@ -430,7 +430,7 @@ fn match_arm(p: &mut Parser) -> BlockLike {
     // }
     attributes::outer_attributes(p);
 
-    patterns::pattern_list_r(p, TokenSet::EMPTY);
+    patterns::pattern_top_r(p, TokenSet::EMPTY);
     if p.at(T![if]) {
         match_guard(p);
     }
diff --git a/crates/ra_parser/src/grammar/params.rs b/crates/ra_parser/src/grammar/params.rs
index 94edc7f35..272661b1d 100644
--- a/crates/ra_parser/src/grammar/params.rs
+++ b/crates/ra_parser/src/grammar/params.rs
@@ -114,9 +114,12 @@ fn value_parameter(p: &mut Parser, flavor: Flavor) {
         // test fn_pointer_param_ident_path
         // type Foo = fn(Bar::Baz);
         // type Qux = fn(baz: Bar::Baz);
+
+        // test fn_pointer_unnamed_arg
+        // type Foo = fn(_: bar);
         Flavor::FnPointer => {
-            if p.at(IDENT) && p.nth(1) == T![:] && !p.nth_at(1, T![::]) {
-                patterns::pattern(p);
+            if (p.at(IDENT) || p.at(UNDERSCORE)) && p.nth(1) == T![:] && !p.nth_at(1, T![::]) {
+                patterns::pattern_single(p);
                 types::ascription(p);
             } else {
                 types::type_(p);
@@ -127,7 +130,7 @@ fn value_parameter(p: &mut Parser, flavor: Flavor) {
         //    let foo = |bar, baz: Baz, qux: Qux::Quux| ();
         // }
         Flavor::Closure => {
-            patterns::pattern(p);
+            patterns::pattern_single(p);
             if p.at(T![:]) && !p.at(T![::]) {
                 types::ascription(p);
             }
diff --git a/crates/ra_parser/src/grammar/patterns.rs b/crates/ra_parser/src/grammar/patterns.rs
index 422a4e3dc..3afbaa82b 100644
--- a/crates/ra_parser/src/grammar/patterns.rs
+++ b/crates/ra_parser/src/grammar/patterns.rs
@@ -11,22 +11,47 @@ pub(crate) fn pattern(p: &mut Parser) {
 }
 
 /// Parses a pattern list separated by pipes `|`
-pub(super) fn pattern_list(p: &mut Parser) {
-    pattern_list_r(p, PAT_RECOVERY_SET)
+pub(super) fn pattern_top(p: &mut Parser) {
+    pattern_top_r(p, PAT_RECOVERY_SET)
+}
+
+pub(crate) fn pattern_single(p: &mut Parser) {
+    pattern_single_r(p, PAT_RECOVERY_SET);
 }
 
 /// Parses a pattern list separated by pipes `|`
 /// using the given `recovery_set`
-pub(super) fn pattern_list_r(p: &mut Parser, recovery_set: TokenSet) {
+pub(super) fn pattern_top_r(p: &mut Parser, recovery_set: TokenSet) {
     p.eat(T![|]);
     pattern_r(p, recovery_set);
+}
 
+/// Parses a pattern list separated by pipes `|`, with no leading `|`,using the
+/// given `recovery_set`
+// test or_pattern
+// fn main() {
+//     match () {
+//         (_ | _) => (),
+//         &(_ | _) => (),
+//         (_ | _,) => (),
+//         [_ | _,] => (),
+//     }
+// }
+fn pattern_r(p: &mut Parser, recovery_set: TokenSet) {
+    let m = p.start();
+    pattern_single_r(p, recovery_set);
+
+    if !p.at(T![|]) {
+        m.abandon(p);
+        return;
+    }
     while p.eat(T![|]) {
-        pattern_r(p, recovery_set);
+        pattern_single_r(p, recovery_set);
     }
+    m.complete(p, OR_PAT);
 }
 
-pub(super) fn pattern_r(p: &mut Parser, recovery_set: TokenSet) {
+fn pattern_single_r(p: &mut Parser, recovery_set: TokenSet) {
     if let Some(lhs) = atom_pat(p, recovery_set) {
         // test range_pat
         // fn main() {
@@ -258,19 +283,41 @@ fn ref_pat(p: &mut Parser) -> CompletedMarker {
     let m = p.start();
     p.bump(T![&]);
     p.eat(T![mut]);
-    pattern(p);
+    pattern_single(p);
     m.complete(p, REF_PAT)
 }
 
 // test tuple_pat
 // fn main() {
 //     let (a, b, ..) = ();
+//     let (a,) = ();
+//     let (..) = ();
+//     let () = ();
 // }
 fn tuple_pat(p: &mut Parser) -> CompletedMarker {
     assert!(p.at(T!['(']));
     let m = p.start();
-    tuple_pat_fields(p);
-    m.complete(p, TUPLE_PAT)
+    p.bump(T!['(']);
+    let mut has_comma = false;
+    let mut has_pat = false;
+    let mut has_rest = false;
+    while !p.at(EOF) && !p.at(T![')']) {
+        has_pat = true;
+        if !p.at_ts(PATTERN_FIRST) {
+            p.error("expected a pattern");
+            break;
+        }
+        has_rest |= p.at(T![..]);
+
+        pattern(p);
+        if !p.at(T![')']) {
+            has_comma = true;
+            p.expect(T![,]);
+        }
+    }
+    p.expect(T![')']);
+
+    m.complete(p, if !has_comma && !has_rest && has_pat { PAREN_PAT } else { TUPLE_PAT })
 }
 
 // test slice_pat
@@ -315,7 +362,7 @@ fn bind_pat(p: &mut Parser, with_at: bool) -> CompletedMarker {
     p.eat(T![mut]);
     name(p);
     if with_at && p.eat(T![@]) {
-        pattern(p);
+        pattern_single(p);
     }
     m.complete(p, BIND_PAT)
 }
@@ -330,6 +377,6 @@ fn box_pat(p: &mut Parser) -> CompletedMarker {
     assert!(p.at(T![box]));
     let m = p.start();
     p.bump(T![box]);
-    pattern(p);
+    pattern_single(p);
     m.complete(p, BOX_PAT)
 }
diff --git a/crates/ra_parser/src/syntax_kind/generated.rs b/crates/ra_parser/src/syntax_kind/generated.rs
index e27b27ffa..1068da0a0 100644
--- a/crates/ra_parser/src/syntax_kind/generated.rs
+++ b/crates/ra_parser/src/syntax_kind/generated.rs
@@ -151,6 +151,8 @@ pub enum SyntaxKind {
     FOR_TYPE,
     IMPL_TRAIT_TYPE,
     DYN_TRAIT_TYPE,
+    OR_PAT,
+    PAREN_PAT,
     REF_PAT,
     BOX_PAT,
     BIND_PAT,
diff --git a/crates/ra_prof/src/lib.rs b/crates/ra_prof/src/lib.rs
index d38ff397e..c0bfbc2ee 100644
--- a/crates/ra_prof/src/lib.rs
+++ b/crates/ra_prof/src/lib.rs
@@ -26,6 +26,13 @@ pub use crate::memory_usage::{Bytes, MemoryUsage};
 #[global_allocator]
 static ALLOC: jemallocator::Jemalloc = jemallocator::Jemalloc;
 
+pub fn init() {
+    set_filter(match std::env::var("RA_PROFILE") {
+        Ok(spec) => Filter::from_spec(&spec),
+        Err(_) => Filter::disabled(),
+    });
+}
+
 /// Set profiling filter. It specifies descriptions allowed to profile.
 /// This is helpful when call stack has too many nested profiling scopes.
 /// Additionally filter can specify maximum depth of profiling scopes nesting.
diff --git a/crates/ra_project_model/Cargo.toml b/crates/ra_project_model/Cargo.toml
index 69edc3c66..653d5bd14 100644
--- a/crates/ra_project_model/Cargo.toml
+++ b/crates/ra_project_model/Cargo.toml
@@ -19,3 +19,5 @@ ra_cfg = { path = "../ra_cfg" }
 
 serde = { version = "1.0.89", features = ["derive"] }
 serde_json = "1.0.39"
+
+anyhow = "1.0.26"
diff --git a/crates/ra_project_model/src/cargo_workspace.rs b/crates/ra_project_model/src/cargo_workspace.rs
index 60cb8c1eb..22d226a74 100644
--- a/crates/ra_project_model/src/cargo_workspace.rs
+++ b/crates/ra_project_model/src/cargo_workspace.rs
@@ -2,14 +2,13 @@
 
 use std::path::{Path, PathBuf};
 
+use anyhow::{Context, Result};
 use cargo_metadata::{CargoOpt, MetadataCommand};
 use ra_arena::{impl_arena_id, Arena, RawId};
 use ra_db::Edition;
 use rustc_hash::FxHashMap;
 use serde::Deserialize;
 
-use crate::Result;
-
 /// `CargoWorkspace` represents the logical structure of, well, a Cargo
 /// workspace. It pretty closely mirrors `cargo metadata` output.
 ///
@@ -171,7 +170,9 @@ impl CargoWorkspace {
         if let Some(parent) = cargo_toml.parent() {
             meta.current_dir(parent);
         }
-        let meta = meta.exec().map_err(|e| format!("cargo metadata failed: {}", e))?;
+        let meta = meta.exec().with_context(|| {
+            format!("Failed to run `cargo metadata --manifest-path {}`", cargo_toml.display())
+        })?;
         let mut pkg_by_id = FxHashMap::default();
         let mut packages = Arena::default();
         let mut targets = Arena::default();
@@ -181,7 +182,9 @@ impl CargoWorkspace {
         for meta_pkg in meta.packages {
             let cargo_metadata::Package { id, edition, name, manifest_path, .. } = meta_pkg;
             let is_member = ws_members.contains(&id);
-            let edition = edition.parse::<Edition>()?;
+            let edition = edition
+                .parse::<Edition>()
+                .with_context(|| format!("Failed to parse edition {}", edition))?;
             let pkg = packages.alloc(PackageData {
                 name,
                 manifest: manifest_path,
diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index bc1d15406..250255813 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -12,6 +12,7 @@ use std::{
     process::Command,
 };
 
+use anyhow::{bail, Context, Result};
 use ra_cfg::CfgOptions;
 use ra_db::{CrateGraph, CrateId, CrateName, Edition, Env, FileId};
 use rustc_hash::FxHashMap;
@@ -23,8 +24,6 @@ pub use crate::{
     sysroot::Sysroot,
 };
 
-pub type Result<T> = ::std::result::Result<T, Box<dyn Error + Send + Sync>>;
-
 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub struct CargoTomlNotFoundError(pub PathBuf);
 
@@ -81,15 +80,36 @@ impl ProjectWorkspace {
     ) -> Result<ProjectWorkspace> {
         match find_rust_project_json(path) {
             Some(json_path) => {
-                let file = File::open(json_path)?;
+                let file = File::open(&json_path)
+                    .with_context(|| format!("Failed to open json file {}", json_path.display()))?;
                 let reader = BufReader::new(file);
-                Ok(ProjectWorkspace::Json { project: from_reader(reader)? })
+                Ok(ProjectWorkspace::Json {
+                    project: from_reader(reader).with_context(|| {
+                        format!("Failed to deserialize json file {}", json_path.display())
+                    })?,
+                })
             }
             None => {
-                let cargo_toml = find_cargo_toml(path)?;
-                let cargo = CargoWorkspace::from_cargo_metadata(&cargo_toml, cargo_features)?;
-                let sysroot =
-                    if with_sysroot { Sysroot::discover(&cargo_toml)? } else { Sysroot::default() };
+                let cargo_toml = find_cargo_toml(path).with_context(|| {
+                    format!("Failed to find Cargo.toml for path {}", path.display())
+                })?;
+                let cargo = CargoWorkspace::from_cargo_metadata(&cargo_toml, cargo_features)
+                    .with_context(|| {
+                        format!(
+                            "Failed to read Cargo metadata from Cargo.toml file {}",
+                            cargo_toml.display()
+                        )
+                    })?;
+                let sysroot = if with_sysroot {
+                    Sysroot::discover(&cargo_toml).with_context(|| {
+                        format!(
+                            "Failed to find sysroot for Cargo.toml file {}",
+                            cargo_toml.display()
+                        )
+                    })?
+                } else {
+                    Sysroot::default()
+                };
                 Ok(ProjectWorkspace::Cargo { cargo, sysroot })
             }
         }
@@ -398,16 +418,27 @@ pub fn get_rustc_cfg_options() -> CfgOptions {
     // Some nightly-only cfgs, which are required for stdlib
     {
         cfg_options.insert_atom("target_thread_local".into());
-        for &target_has_atomic in ["16", "32", "64", "8", "cas", "ptr"].iter() {
-            cfg_options.insert_key_value("target_has_atomic".into(), target_has_atomic.into())
+        for &target_has_atomic in ["8", "16", "32", "64", "cas", "ptr"].iter() {
+            cfg_options.insert_key_value("target_has_atomic".into(), target_has_atomic.into());
+            cfg_options
+                .insert_key_value("target_has_atomic_load_store".into(), target_has_atomic.into());
         }
     }
 
-    match (|| -> Result<_> {
+    match (|| -> Result<String> {
         // `cfg(test)` and `cfg(debug_assertion)` are handled outside, so we suppress them here.
-        let output = Command::new("rustc").args(&["--print", "cfg", "-O"]).output()?;
+        let output = Command::new("rustc")
+            .args(&["--print", "cfg", "-O"])
+            .output()
+            .context("Failed to get output from rustc --print cfg -O")?;
         if !output.status.success() {
-            Err("failed to get rustc cfgs")?;
+            bail!(
+                "rustc --print cfg -O exited with exit code ({})",
+                output
+                    .status
+                    .code()
+                    .map_or(String::from("no exit code"), |code| format!("{}", code))
+            );
         }
         Ok(String::from_utf8(output.stdout)?)
     })() {
diff --git a/crates/ra_project_model/src/sysroot.rs b/crates/ra_project_model/src/sysroot.rs
index 34d066b1e..7b9cc899c 100644
--- a/crates/ra_project_model/src/sysroot.rs
+++ b/crates/ra_project_model/src/sysroot.rs
@@ -1,5 +1,6 @@
 //! FIXME: write short doc here
 
+use anyhow::{anyhow, bail, Context, Result};
 use std::{
     env,
     path::{Path, PathBuf},
@@ -8,8 +9,6 @@ use std::{
 
 use ra_arena::{impl_arena_id, Arena, RawId};
 
-use crate::Result;
-
 #[derive(Default, Debug, Clone)]
 pub struct Sysroot {
     crates: Arena<SysrootCrate, SysrootCrateData>,
@@ -51,7 +50,7 @@ impl Sysroot {
         let src = try_find_src_path(cargo_toml)?;
 
         if !src.exists() {
-            Err(format!(
+            Err(anyhow!(
                 "can't load standard library from sysroot\n\
                  {}\n\
                  (discovered via `rustc --print sysroot`)\n\
@@ -99,9 +98,15 @@ fn try_find_src_path(cargo_toml: &Path) -> Result<PathBuf> {
     let rustc_output = Command::new("rustc")
         .current_dir(cargo_toml.parent().unwrap())
         .args(&["--print", "sysroot"])
-        .output()?;
+        .output()
+        .context("rustc --print sysroot failed")?;
     if !rustc_output.status.success() {
-        Err("failed to locate sysroot")?;
+        match rustc_output.status.code() {
+            Some(code) => {
+                bail!("failed to locate sysroot: rustc --print sysroot exited with code {}", code)
+            }
+            None => bail!("failed to locate sysroot: rustc --print sysroot terminated by signal"),
+        };
     }
     let stdout = String::from_utf8(rustc_output.stdout)?;
     let sysroot_path = Path::new(stdout.trim());
diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index 89cb9a9f3..9cc7930f7 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -18,7 +18,8 @@ use crate::{
 pub use self::{
     expr_extensions::{ArrayExprKind, BinOp, ElseBranch, LiteralKind, PrefixOp, RangeOp},
     extensions::{
-        FieldKind, PathSegmentKind, SelfParamKind, StructKind, TypeBoundKind, VisibilityKind,
+        AttrKind, FieldKind, PathSegmentKind, SelfParamKind, SlicePatComponents, StructKind,
+        TypeBoundKind, VisibilityKind,
     },
     generated::*,
     tokens::*,
@@ -216,10 +217,7 @@ fn test_doc_comment_multi_line_block_strips_suffix() {
 #[test]
 fn test_comments_preserve_trailing_whitespace() {
     let file = SourceFile::parse(
-        r#"
-/// Representation of a Realm.   
-/// In the specification these are called Realm Records.
-struct Realm {}"#,
+        "\n/// Representation of a Realm.   \n/// In the specification these are called Realm Records.\nstruct Realm {}",
     )
     .ok()
     .unwrap();
diff --git a/crates/ra_syntax/src/ast/extensions.rs b/crates/ra_syntax/src/ast/extensions.rs
index cb0aee422..44de4af89 100644
--- a/crates/ra_syntax/src/ast/extensions.rs
+++ b/crates/ra_syntax/src/ast/extensions.rs
@@ -1,6 +1,8 @@
 //! Various extension methods to ast Nodes, which are hard to code-generate.
 //! Extensions for various expressions live in a sibling `expr_extensions` module.
 
+use itertools::Itertools;
+
 use crate::{
     ast::{self, child_opt, children, AstNode, AttrInput, SyntaxNode},
     SmolStr, SyntaxElement,
@@ -35,6 +37,12 @@ fn text_of_first_token(node: &SyntaxNode) -> &SmolStr {
     node.green().children().next().and_then(|it| it.into_token()).unwrap().text()
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum AttrKind {
+    Inner,
+    Outer,
+}
+
 impl ast::Attr {
     pub fn as_simple_atom(&self) -> Option<SmolStr> {
         match self.input() {
@@ -69,6 +77,18 @@ impl ast::Attr {
             _ => None,
         }
     }
+
+    pub fn kind(&self) -> AttrKind {
+        let first_token = self.syntax().first_token();
+        let first_token_kind = first_token.as_ref().map(SyntaxToken::kind);
+        let second_token_kind =
+            first_token.and_then(|token| token.next_token()).as_ref().map(SyntaxToken::kind);
+
+        match (first_token_kind, second_token_kind) {
+            (Some(SyntaxKind::POUND), Some(SyntaxKind::EXCL)) => AttrKind::Inner,
+            _ => AttrKind::Outer,
+        }
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -293,6 +313,40 @@ impl ast::BindPat {
     }
 }
 
+pub struct SlicePatComponents {
+    pub prefix: Vec<ast::Pat>,
+    pub slice: Option<ast::Pat>,
+    pub suffix: Vec<ast::Pat>,
+}
+
+impl ast::SlicePat {
+    pub fn components(&self) -> SlicePatComponents {
+        let mut args = self.args().peekable();
+        let prefix = args
+            .peeking_take_while(|p| match p {
+                ast::Pat::DotDotPat(_) => false,
+                ast::Pat::BindPat(bp) => match bp.pat() {
+                    Some(ast::Pat::DotDotPat(_)) => false,
+                    _ => true,
+                },
+                ast::Pat::RefPat(rp) => match rp.pat() {
+                    Some(ast::Pat::DotDotPat(_)) => false,
+                    Some(ast::Pat::BindPat(bp)) => match bp.pat() {
+                        Some(ast::Pat::DotDotPat(_)) => false,
+                        _ => true,
+                    },
+                    _ => true,
+                },
+                _ => true,
+            })
+            .collect();
+        let slice = args.next();
+        let suffix = args.collect();
+
+        SlicePatComponents { prefix, slice, suffix }
+    }
+}
+
 impl ast::PointerType {
     pub fn is_mut(&self) -> bool {
         self.syntax().children_with_tokens().any(|n| n.kind() == T![mut])
diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index 435135f92..8eb240801 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -1759,8 +1759,8 @@ impl AstNode for MatchArm {
 }
 impl ast::AttrsOwner for MatchArm {}
 impl MatchArm {
-    pub fn pats(&self) -> AstChildren<Pat> {
-        AstChildren::new(&self.syntax)
+    pub fn pat(&self) -> Option<Pat> {
+        AstChildren::new(&self.syntax).next()
     }
     pub fn guard(&self) -> Option<MatchGuard> {
         AstChildren::new(&self.syntax).next()
@@ -1887,6 +1887,60 @@ impl RecordField {
     }
 }
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct OrPat {
+    pub(crate) syntax: SyntaxNode,
+}
+impl AstNode for OrPat {
+    fn can_cast(kind: SyntaxKind) -> bool {
+        match kind {
+            OR_PAT => true,
+            _ => false,
+        }
+    }
+    fn cast(syntax: SyntaxNode) -> Option<Self> {
+        if Self::can_cast(syntax.kind()) {
+            Some(Self { syntax })
+        } else {
+            None
+        }
+    }
+    fn syntax(&self) -> &SyntaxNode {
+        &self.syntax
+    }
+}
+impl OrPat {
+    pub fn pats(&self) -> AstChildren<Pat> {
+        AstChildren::new(&self.syntax)
+    }
+}
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct ParenPat {
+    pub(crate) syntax: SyntaxNode,
+}
+impl AstNode for ParenPat {
+    fn can_cast(kind: SyntaxKind) -> bool {
+        match kind {
+            PAREN_PAT => true,
+            _ => false,
+        }
+    }
+    fn cast(syntax: SyntaxNode) -> Option<Self> {
+        if Self::can_cast(syntax.kind()) {
+            Some(Self { syntax })
+        } else {
+            None
+        }
+    }
+    fn syntax(&self) -> &SyntaxNode {
+        &self.syntax
+    }
+}
+impl ParenPat {
+    pub fn pat(&self) -> Option<Pat> {
+        AstChildren::new(&self.syntax).next()
+    }
+}
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct RefPat {
     pub(crate) syntax: SyntaxNode,
 }
@@ -2063,7 +2117,11 @@ impl AstNode for SlicePat {
         &self.syntax
     }
 }
-impl SlicePat {}
+impl SlicePat {
+    pub fn args(&self) -> AstChildren<Pat> {
+        AstChildren::new(&self.syntax)
+    }
+}
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct RangePat {
     pub(crate) syntax: SyntaxNode,
@@ -3900,6 +3958,8 @@ impl AstNode for Expr {
 }
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum Pat {
+    OrPat(OrPat),
+    ParenPat(ParenPat),
     RefPat(RefPat),
     BoxPat(BoxPat),
     BindPat(BindPat),
@@ -3913,6 +3973,16 @@ pub enum Pat {
     RangePat(RangePat),
     LiteralPat(LiteralPat),
 }
+impl From<OrPat> for Pat {
+    fn from(node: OrPat) -> Pat {
+        Pat::OrPat(node)
+    }
+}
+impl From<ParenPat> for Pat {
+    fn from(node: ParenPat) -> Pat {
+        Pat::ParenPat(node)
+    }
+}
 impl From<RefPat> for Pat {
     fn from(node: RefPat) -> Pat {
         Pat::RefPat(node)
@@ -3976,15 +4046,16 @@ impl From<LiteralPat> for Pat {
 impl AstNode for Pat {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
-            REF_PAT | BOX_PAT | BIND_PAT | PLACEHOLDER_PAT | DOT_DOT_PAT | PATH_PAT
-            | RECORD_PAT | TUPLE_STRUCT_PAT | TUPLE_PAT | SLICE_PAT | RANGE_PAT | LITERAL_PAT => {
-                true
-            }
+            OR_PAT | PAREN_PAT | REF_PAT | BOX_PAT | BIND_PAT | PLACEHOLDER_PAT | DOT_DOT_PAT
+            | PATH_PAT | RECORD_PAT | TUPLE_STRUCT_PAT | TUPLE_PAT | SLICE_PAT | RANGE_PAT
+            | LITERAL_PAT => true,
             _ => false,
         }
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
+            OR_PAT => Pat::OrPat(OrPat { syntax }),
+            PAREN_PAT => Pat::ParenPat(ParenPat { syntax }),
             REF_PAT => Pat::RefPat(RefPat { syntax }),
             BOX_PAT => Pat::BoxPat(BoxPat { syntax }),
             BIND_PAT => Pat::BindPat(BindPat { syntax }),
@@ -4003,6 +4074,8 @@ impl AstNode for Pat {
     }
     fn syntax(&self) -> &SyntaxNode {
         match self {
+            Pat::OrPat(it) => &it.syntax,
+            Pat::ParenPat(it) => &it.syntax,
             Pat::RefPat(it) => &it.syntax,
             Pat::BoxPat(it) => &it.syntax,
             Pat::BindPat(it) => &it.syntax,
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0030_cond.txt b/crates/ra_syntax/test_data/parser/inline/ok/0030_cond.txt
index 4028ca243..6fd49c7bc 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0030_cond.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0030_cond.txt
@@ -63,27 +63,28 @@ SOURCE_FILE@[0; 197)
             CONDITION@[56; 84)
               LET_KW@[56; 59) "let"
               WHITESPACE@[59; 60) " "
-              TUPLE_STRUCT_PAT@[60; 67)
-                PATH@[60; 64)
-                  PATH_SEGMENT@[60; 64)
-                    NAME_REF@[60; 64)
-                      IDENT@[60; 64) "Some"
-                L_PAREN@[64; 65) "("
-                PLACEHOLDER_PAT@[65; 66)
-                  UNDERSCORE@[65; 66) "_"
-                R_PAREN@[66; 67) ")"
-              WHITESPACE@[67; 68) " "
-              PIPE@[68; 69) "|"
-              WHITESPACE@[69; 70) " "
-              TUPLE_STRUCT_PAT@[70; 77)
-                PATH@[70; 74)
-                  PATH_SEGMENT@[70; 74)
-                    NAME_REF@[70; 74)
-                      IDENT@[70; 74) "Some"
-                L_PAREN@[74; 75) "("
-                PLACEHOLDER_PAT@[75; 76)
-                  UNDERSCORE@[75; 76) "_"
-                R_PAREN@[76; 77) ")"
+              OR_PAT@[60; 77)
+                TUPLE_STRUCT_PAT@[60; 67)
+                  PATH@[60; 64)
+                    PATH_SEGMENT@[60; 64)
+                      NAME_REF@[60; 64)
+                        IDENT@[60; 64) "Some"
+                  L_PAREN@[64; 65) "("
+                  PLACEHOLDER_PAT@[65; 66)
+                    UNDERSCORE@[65; 66) "_"
+                  R_PAREN@[66; 67) ")"
+                WHITESPACE@[67; 68) " "
+                PIPE@[68; 69) "|"
+                WHITESPACE@[69; 70) " "
+                TUPLE_STRUCT_PAT@[70; 77)
+                  PATH@[70; 74)
+                    PATH_SEGMENT@[70; 74)
+                      NAME_REF@[70; 74)
+                        IDENT@[70; 74) "Some"
+                  L_PAREN@[74; 75) "("
+                  PLACEHOLDER_PAT@[75; 76)
+                    UNDERSCORE@[75; 76) "_"
+                  R_PAREN@[76; 77) ")"
               WHITESPACE@[77; 78) " "
               EQ@[78; 79) "="
               WHITESPACE@[79; 80) " "
@@ -137,27 +138,28 @@ SOURCE_FILE@[0; 197)
             CONDITION@[129; 157)
               LET_KW@[129; 132) "let"
               WHITESPACE@[132; 133) " "
-              TUPLE_STRUCT_PAT@[133; 140)
-                PATH@[133; 137)
-                  PATH_SEGMENT@[133; 137)
-                    NAME_REF@[133; 137)
-                      IDENT@[133; 137) "Some"
-                L_PAREN@[137; 138) "("
-                PLACEHOLDER_PAT@[138; 139)
-                  UNDERSCORE@[138; 139) "_"
-                R_PAREN@[139; 140) ")"
-              WHITESPACE@[140; 141) " "
-              PIPE@[141; 142) "|"
-              WHITESPACE@[142; 143) " "
-              TUPLE_STRUCT_PAT@[143; 150)
-                PATH@[143; 147)
-                  PATH_SEGMENT@[143; 147)
-                    NAME_REF@[143; 147)
-                      IDENT@[143; 147) "Some"
-                L_PAREN@[147; 148) "("
-                PLACEHOLDER_PAT@[148; 149)
-                  UNDERSCORE@[148; 149) "_"
-                R_PAREN@[149; 150) ")"
+              OR_PAT@[133; 150)
+                TUPLE_STRUCT_PAT@[133; 140)
+                  PATH@[133; 137)
+                    PATH_SEGMENT@[133; 137)
+                      NAME_REF@[133; 137)
+                        IDENT@[133; 137) "Some"
+                  L_PAREN@[137; 138) "("
+                  PLACEHOLDER_PAT@[138; 139)
+                    UNDERSCORE@[138; 139) "_"
+                  R_PAREN@[139; 140) ")"
+                WHITESPACE@[140; 141) " "
+                PIPE@[141; 142) "|"
+                WHITESPACE@[142; 143) " "
+                TUPLE_STRUCT_PAT@[143; 150)
+                  PATH@[143; 147)
+                    PATH_SEGMENT@[143; 147)
+                      NAME_REF@[143; 147)
+                        IDENT@[143; 147) "Some"
+                  L_PAREN@[147; 148) "("
+                  PLACEHOLDER_PAT@[148; 149)
+                    UNDERSCORE@[148; 149) "_"
+                  R_PAREN@[149; 150) ")"
               WHITESPACE@[150; 151) " "
               EQ@[151; 152) "="
               WHITESPACE@[152; 153) " "
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0066_match_arm.txt b/crates/ra_syntax/test_data/parser/inline/ok/0066_match_arm.txt
index 87272917b..2f07af4e1 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0066_match_arm.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0066_match_arm.txt
@@ -74,15 +74,16 @@ SOURCE_FILE@[0; 167)
               COMMA@[83; 84) ","
               WHITESPACE@[84; 93) "\n        "
               MATCH_ARM@[93; 109)
-                BIND_PAT@[93; 94)
-                  NAME@[93; 94)
-                    IDENT@[93; 94) "X"
-                WHITESPACE@[94; 95) " "
-                PIPE@[95; 96) "|"
-                WHITESPACE@[96; 97) " "
-                BIND_PAT@[97; 98)
-                  NAME@[97; 98)
-                    IDENT@[97; 98) "Y"
+                OR_PAT@[93; 98)
+                  BIND_PAT@[93; 94)
+                    NAME@[93; 94)
+                      IDENT@[93; 94) "X"
+                  WHITESPACE@[94; 95) " "
+                  PIPE@[95; 96) "|"
+                  WHITESPACE@[96; 97) " "
+                  BIND_PAT@[97; 98)
+                    NAME@[97; 98)
+                      IDENT@[97; 98) "Y"
                 WHITESPACE@[98; 99) " "
                 MATCH_GUARD@[99; 103)
                   IF_KW@[99; 101) "if"
@@ -103,15 +104,16 @@ SOURCE_FILE@[0; 167)
               MATCH_ARM@[119; 137)
                 PIPE@[119; 120) "|"
                 WHITESPACE@[120; 121) " "
-                BIND_PAT@[121; 122)
-                  NAME@[121; 122)
-                    IDENT@[121; 122) "X"
-                WHITESPACE@[122; 123) " "
-                PIPE@[123; 124) "|"
-                WHITESPACE@[124; 125) " "
-                BIND_PAT@[125; 126)
-                  NAME@[125; 126)
-                    IDENT@[125; 126) "Y"
+                OR_PAT@[121; 126)
+                  BIND_PAT@[121; 122)
+                    NAME@[121; 122)
+                      IDENT@[121; 122) "X"
+                  WHITESPACE@[122; 123) " "
+                  PIPE@[123; 124) "|"
+                  WHITESPACE@[124; 125) " "
+                  BIND_PAT@[125; 126)
+                    NAME@[125; 126)
+                      IDENT@[125; 126) "Y"
                 WHITESPACE@[126; 127) " "
                 MATCH_GUARD@[127; 131)
                   IF_KW@[127; 129) "if"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0111_tuple_pat.rs b/crates/ra_syntax/test_data/parser/inline/ok/0111_tuple_pat.rs
index f785acd36..ba719879d 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0111_tuple_pat.rs
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0111_tuple_pat.rs
@@ -1,3 +1,6 @@
 fn main() {
     let (a, b, ..) = ();
+    let (a,) = ();
+    let (..) = ();
+    let () = ();
 }
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0111_tuple_pat.txt b/crates/ra_syntax/test_data/parser/inline/ok/0111_tuple_pat.txt
index 674dec493..4680c267e 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0111_tuple_pat.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0111_tuple_pat.txt
@@ -1,5 +1,5 @@
-SOURCE_FILE@[0; 39)
-  FN_DEF@[0; 38)
+SOURCE_FILE@[0; 94)
+  FN_DEF@[0; 93)
     FN_KW@[0; 2) "fn"
     WHITESPACE@[2; 3) " "
     NAME@[3; 7)
@@ -8,8 +8,8 @@ SOURCE_FILE@[0; 39)
       L_PAREN@[7; 8) "("
       R_PAREN@[8; 9) ")"
     WHITESPACE@[9; 10) " "
-    BLOCK_EXPR@[10; 38)
-      BLOCK@[10; 38)
+    BLOCK_EXPR@[10; 93)
+      BLOCK@[10; 93)
         L_CURLY@[10; 11) "{"
         WHITESPACE@[11; 16) "\n    "
         LET_STMT@[16; 36)
@@ -37,6 +37,54 @@ SOURCE_FILE@[0; 39)
             L_PAREN@[33; 34) "("
             R_PAREN@[34; 35) ")"
           SEMI@[35; 36) ";"
-        WHITESPACE@[36; 37) "\n"
-        R_CURLY@[37; 38) "}"
-  WHITESPACE@[38; 39) "\n"
+        WHITESPACE@[36; 41) "\n    "
+        LET_STMT@[41; 55)
+          LET_KW@[41; 44) "let"
+          WHITESPACE@[44; 45) " "
+          TUPLE_PAT@[45; 49)
+            L_PAREN@[45; 46) "("
+            BIND_PAT@[46; 47)
+              NAME@[46; 47)
+                IDENT@[46; 47) "a"
+            COMMA@[47; 48) ","
+            R_PAREN@[48; 49) ")"
+          WHITESPACE@[49; 50) " "
+          EQ@[50; 51) "="
+          WHITESPACE@[51; 52) " "
+          TUPLE_EXPR@[52; 54)
+            L_PAREN@[52; 53) "("
+            R_PAREN@[53; 54) ")"
+          SEMI@[54; 55) ";"
+        WHITESPACE@[55; 60) "\n    "
+        LET_STMT@[60; 74)
+          LET_KW@[60; 63) "let"
+          WHITESPACE@[63; 64) " "
+          TUPLE_PAT@[64; 68)
+            L_PAREN@[64; 65) "("
+            DOT_DOT_PAT@[65; 67)
+              DOTDOT@[65; 67) ".."
+            R_PAREN@[67; 68) ")"
+          WHITESPACE@[68; 69) " "
+          EQ@[69; 70) "="
+          WHITESPACE@[70; 71) " "
+          TUPLE_EXPR@[71; 73)
+            L_PAREN@[71; 72) "("
+            R_PAREN@[72; 73) ")"
+          SEMI@[73; 74) ";"
+        WHITESPACE@[74; 79) "\n    "
+        LET_STMT@[79; 91)
+          LET_KW@[79; 82) "let"
+          WHITESPACE@[82; 83) " "
+          TUPLE_PAT@[83; 85)
+            L_PAREN@[83; 84) "("
+            R_PAREN@[84; 85) ")"
+          WHITESPACE@[85; 86) " "
+          EQ@[86; 87) "="
+          WHITESPACE@[87; 88) " "
+          TUPLE_EXPR@[88; 90)
+            L_PAREN@[88; 89) "("
+            R_PAREN@[89; 90) ")"
+          SEMI@[90; 91) ";"
+        WHITESPACE@[91; 92) "\n"
+        R_CURLY@[92; 93) "}"
+  WHITESPACE@[93; 94) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0156_or_pattern.rs b/crates/ra_syntax/test_data/parser/inline/ok/0156_or_pattern.rs
new file mode 100644
index 000000000..a26316605
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0156_or_pattern.rs
@@ -0,0 +1,8 @@
+fn main() {
+    match () {
+        (_ | _) => (),
+        &(_ | _) => (),
+        (_ | _,) => (),
+        [_ | _,] => (),
+    }
+}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0156_or_pattern.txt b/crates/ra_syntax/test_data/parser/inline/ok/0156_or_pattern.txt
new file mode 100644
index 000000000..3a196d3c0
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0156_or_pattern.txt
@@ -0,0 +1,112 @@
+SOURCE_FILE@[0; 130)
+  FN_DEF@[0; 129)
+    FN_KW@[0; 2) "fn"
+    WHITESPACE@[2; 3) " "
+    NAME@[3; 7)
+      IDENT@[3; 7) "main"
+    PARAM_LIST@[7; 9)
+      L_PAREN@[7; 8) "("
+      R_PAREN@[8; 9) ")"
+    WHITESPACE@[9; 10) " "
+    BLOCK_EXPR@[10; 129)
+      BLOCK@[10; 129)
+        L_CURLY@[10; 11) "{"
+        WHITESPACE@[11; 16) "\n    "
+        MATCH_EXPR@[16; 127)
+          MATCH_KW@[16; 21) "match"
+          WHITESPACE@[21; 22) " "
+          TUPLE_EXPR@[22; 24)
+            L_PAREN@[22; 23) "("
+            R_PAREN@[23; 24) ")"
+          WHITESPACE@[24; 25) " "
+          MATCH_ARM_LIST@[25; 127)
+            L_CURLY@[25; 26) "{"
+            WHITESPACE@[26; 35) "\n        "
+            MATCH_ARM@[35; 48)
+              PAREN_PAT@[35; 42)
+                L_PAREN@[35; 36) "("
+                OR_PAT@[36; 41)
+                  PLACEHOLDER_PAT@[36; 37)
+                    UNDERSCORE@[36; 37) "_"
+                  WHITESPACE@[37; 38) " "
+                  PIPE@[38; 39) "|"
+                  WHITESPACE@[39; 40) " "
+                  PLACEHOLDER_PAT@[40; 41)
+                    UNDERSCORE@[40; 41) "_"
+                R_PAREN@[41; 42) ")"
+              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; 58) "\n        "
+            MATCH_ARM@[58; 72)
+              REF_PAT@[58; 66)
+                AMP@[58; 59) "&"
+                PAREN_PAT@[59; 66)
+                  L_PAREN@[59; 60) "("
+                  OR_PAT@[60; 65)
+                    PLACEHOLDER_PAT@[60; 61)
+                      UNDERSCORE@[60; 61) "_"
+                    WHITESPACE@[61; 62) " "
+                    PIPE@[62; 63) "|"
+                    WHITESPACE@[63; 64) " "
+                    PLACEHOLDER_PAT@[64; 65)
+                      UNDERSCORE@[64; 65) "_"
+                  R_PAREN@[65; 66) ")"
+              WHITESPACE@[66; 67) " "
+              FAT_ARROW@[67; 69) "=>"
+              WHITESPACE@[69; 70) " "
+              TUPLE_EXPR@[70; 72)
+                L_PAREN@[70; 71) "("
+                R_PAREN@[71; 72) ")"
+            COMMA@[72; 73) ","
+            WHITESPACE@[73; 82) "\n        "
+            MATCH_ARM@[82; 96)
+              TUPLE_PAT@[82; 90)
+                L_PAREN@[82; 83) "("
+                OR_PAT@[83; 88)
+                  PLACEHOLDER_PAT@[83; 84)
+                    UNDERSCORE@[83; 84) "_"
+                  WHITESPACE@[84; 85) " "
+                  PIPE@[85; 86) "|"
+                  WHITESPACE@[86; 87) " "
+                  PLACEHOLDER_PAT@[87; 88)
+                    UNDERSCORE@[87; 88) "_"
+                COMMA@[88; 89) ","
+                R_PAREN@[89; 90) ")"
+              WHITESPACE@[90; 91) " "
+              FAT_ARROW@[91; 93) "=>"
+              WHITESPACE@[93; 94) " "
+              TUPLE_EXPR@[94; 96)
+                L_PAREN@[94; 95) "("
+                R_PAREN@[95; 96) ")"
+            COMMA@[96; 97) ","
+            WHITESPACE@[97; 106) "\n        "
+            MATCH_ARM@[106; 120)
+              SLICE_PAT@[106; 114)
+                L_BRACK@[106; 107) "["
+                OR_PAT@[107; 112)
+                  PLACEHOLDER_PAT@[107; 108)
+                    UNDERSCORE@[107; 108) "_"
+                  WHITESPACE@[108; 109) " "
+                  PIPE@[109; 110) "|"
+                  WHITESPACE@[110; 111) " "
+                  PLACEHOLDER_PAT@[111; 112)
+                    UNDERSCORE@[111; 112) "_"
+                COMMA@[112; 113) ","
+                R_BRACK@[113; 114) "]"
+              WHITESPACE@[114; 115) " "
+              FAT_ARROW@[115; 117) "=>"
+              WHITESPACE@[117; 118) " "
+              TUPLE_EXPR@[118; 120)
+                L_PAREN@[118; 119) "("
+                R_PAREN@[119; 120) ")"
+            COMMA@[120; 121) ","
+            WHITESPACE@[121; 126) "\n    "
+            R_CURLY@[126; 127) "}"
+        WHITESPACE@[127; 128) "\n"
+        R_CURLY@[128; 129) "}"
+  WHITESPACE@[129; 130) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0157_fn_pointer_unnamed_arg.rs b/crates/ra_syntax/test_data/parser/inline/ok/0157_fn_pointer_unnamed_arg.rs
new file mode 100644
index 000000000..1ebbe5b03
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0157_fn_pointer_unnamed_arg.rs
@@ -0,0 +1 @@
+type Foo = fn(_: bar);
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0157_fn_pointer_unnamed_arg.txt b/crates/ra_syntax/test_data/parser/inline/ok/0157_fn_pointer_unnamed_arg.txt
new file mode 100644
index 000000000..52d8f21a4
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0157_fn_pointer_unnamed_arg.txt
@@ -0,0 +1,26 @@
+SOURCE_FILE@[0; 23)
+  TYPE_ALIAS_DEF@[0; 22)
+    TYPE_KW@[0; 4) "type"
+    WHITESPACE@[4; 5) " "
+    NAME@[5; 8)
+      IDENT@[5; 8) "Foo"
+    WHITESPACE@[8; 9) " "
+    EQ@[9; 10) "="
+    WHITESPACE@[10; 11) " "
+    FN_POINTER_TYPE@[11; 21)
+      FN_KW@[11; 13) "fn"
+      PARAM_LIST@[13; 21)
+        L_PAREN@[13; 14) "("
+        PARAM@[14; 20)
+          PLACEHOLDER_PAT@[14; 15)
+            UNDERSCORE@[14; 15) "_"
+          COLON@[15; 16) ":"
+          WHITESPACE@[16; 17) " "
+          PATH_TYPE@[17; 20)
+            PATH@[17; 20)
+              PATH_SEGMENT@[17; 20)
+                NAME_REF@[17; 20)
+                  IDENT@[17; 20) "bar"
+        R_PAREN@[20; 21) ")"
+    SEMI@[21; 22) ";"
+  WHITESPACE@[22; 23) "\n"
diff --git a/crates/ra_text_edit/src/lib.rs b/crates/ra_text_edit/src/lib.rs
index 5f1b12222..37f23d043 100644
--- a/crates/ra_text_edit/src/lib.rs
+++ b/crates/ra_text_edit/src/lib.rs
@@ -29,8 +29,8 @@ impl AtomTextEdit {
     }
 
     pub fn apply(&self, mut text: String) -> String {
-        let start = u32::from(self.delete.start()) as usize;
-        let end = u32::from(self.delete.end()) as usize;
+        let start = self.delete.start().to_usize();
+        let end = self.delete.end().to_usize();
         text.replace_range(start..end, &self.insert);
         text
     }
diff --git a/crates/ra_text_edit/src/text_edit.rs b/crates/ra_text_edit/src/text_edit.rs
index 413c7d782..3291ada42 100644
--- a/crates/ra_text_edit/src/text_edit.rs
+++ b/crates/ra_text_edit/src/text_edit.rs
@@ -66,13 +66,13 @@ impl TextEdit {
         let mut total_len = text.len();
         for atom in self.atoms.iter() {
             total_len += atom.insert.len();
-            total_len -= u32::from(atom.delete.end() - atom.delete.start()) as usize;
+            total_len -= (atom.delete.end() - atom.delete.start()).to_usize();
         }
         let mut buf = String::with_capacity(total_len);
         let mut prev = 0;
         for atom in self.atoms.iter() {
-            let start = u32::from(atom.delete.start()) as usize;
-            let end = u32::from(atom.delete.end()) as usize;
+            let start = atom.delete.start().to_usize();
+            let end = atom.delete.end().to_usize();
             if start > prev {
                 buf.push_str(&text[prev..start]);
             }