44 files changed, 598 insertions, 129 deletions
diff --git a/crates/assists/src/handlers/extract_assignment.rs b/crates/assists/src/handlers/pull_assignment_up.rs
index ae99598c0..560d93e10 100644
--- a/crates/assists/src/handlers/extract_assignment.rs
+++ b/crates/assists/src/handlers/pull_assignment_up.rs
@@ -9,9 +9,9 @@ use crate::{
    AssistId, AssistKind,
 };
-// Assist: extract_assignment
+// Assist: pull_assignment_up
 //
-// Extracts variable assigment to outside an if or match statement.
+// Extracts variable assignment to outside an if or match statement.
 //
 // ```
 // fn main() {
@@ -36,7 +36,7 @@ use crate::{
 //     };
 // }
 // ```
-pub(crate) fn extract_assigment(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+pub(crate) fn pull_assignment_up(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
    let assign_expr = ctx.find_node_at_offset::<ast::BinExpr>()?;
    let name_expr = if assign_expr.op_kind()? == ast::BinOp::Assignment {
        assign_expr.lhs()?
@@ -61,8 +61,8 @@ pub(crate) fn extract_assigment(acc: &mut Assists, ctx: &AssistContext) -> Optio
    let expr_stmt = make::expr_stmt(new_stmt);
    acc.add(
-        AssistId("extract_assignment", AssistKind::RefactorExtract),
+        AssistId("pull_assignment_up", AssistKind::RefactorExtract),
-        "Extract assignment",
+        "Pull assignment up",
        old_stmt.syntax().text_range(),
        move |edit| {
            edit.replace(old_stmt.syntax().text_range(), format!("{} = {};", name_expr, expr_stmt));
@@ -104,7 +104,7 @@ fn exprify_if(
            ast::ElseBranch::Block(exprify_block(block, sema, name)?)
        }
        ast::ElseBranch::IfExpr(expr) => {
-            mark::hit!(test_extract_assigment_chained_if);
+            mark::hit!(test_pull_assignment_up_chained_if);
            ast::ElseBranch::IfExpr(ast::IfExpr::cast(
                exprify_if(&expr, sema, name)?.syntax().to_owned(),
            )?)
@@ -144,7 +144,7 @@ fn is_equivalent(
 ) -> bool {
    match (expr0, expr1) {
        (ast::Expr::FieldExpr(field_expr0), ast::Expr::FieldExpr(field_expr1)) => {
-            mark::hit!(test_extract_assignment_field_assignment);
+            mark::hit!(test_pull_assignment_up_field_assignment);
            sema.resolve_field(field_expr0) == sema.resolve_field(field_expr1)
        }
        (ast::Expr::PathExpr(path0), ast::Expr::PathExpr(path1)) => {
@@ -167,9 +167,9 @@ mod tests {
    use crate::tests::{check_assist, check_assist_not_applicable};
    #[test]
-    fn test_extract_assignment_if() {
+    fn test_pull_assignment_up_if() {
        check_assist(
-            extract_assigment,
+            pull_assignment_up,
            r#"
 fn foo() {
    let mut a = 1;
@@ -194,9 +194,9 @@ fn foo() {
    }
    #[test]
-    fn test_extract_assignment_match() {
+    fn test_pull_assignment_up_match() {
        check_assist(
-            extract_assigment,
+            pull_assignment_up,
            r#"
 fn foo() {
    let mut a = 1;
@@ -233,9 +233,9 @@ fn foo() {
    }
    #[test]
-    fn test_extract_assignment_not_last_not_applicable() {
+    fn test_pull_assignment_up_not_last_not_applicable() {
        check_assist_not_applicable(
-            extract_assigment,
+            pull_assignment_up,
            r#"
 fn foo() {
    let mut a = 1;
@@ -251,10 +251,10 @@ fn foo() {
    }
    #[test]
-    fn test_extract_assignment_chained_if() {
+    fn test_pull_assignment_up_chained_if() {
-        mark::check!(test_extract_assigment_chained_if);
+        mark::check!(test_pull_assignment_up_chained_if);
        check_assist(
-            extract_assigment,
+            pull_assignment_up,
            r#"
 fn foo() {
    let mut a = 1;
@@ -283,9 +283,9 @@ fn foo() {
    }
    #[test]
-    fn test_extract_assigment_retains_stmts() {
+    fn test_pull_assignment_up_retains_stmts() {
        check_assist(
-            extract_assigment,
+            pull_assignment_up,
            r#"
 fn foo() {
    let mut a = 1;
@@ -314,9 +314,9 @@ fn foo() {
    }
    #[test]
-    fn extract_assignment_let_stmt_not_applicable() {
+    fn pull_assignment_up_let_stmt_not_applicable() {
        check_assist_not_applicable(
-            extract_assigment,
+            pull_assignment_up,
            r#"
 fn foo() {
    let mut a = 1;
@@ -331,9 +331,9 @@ fn foo() {
    }
    #[test]
-    fn extract_assignment_if_missing_assigment_not_applicable() {
+    fn pull_assignment_up_if_missing_assigment_not_applicable() {
        check_assist_not_applicable(
-            extract_assigment,
+            pull_assignment_up,
            r#"
 fn foo() {
    let mut a = 1;
@@ -346,9 +346,9 @@ fn foo() {
    }
    #[test]
-    fn extract_assignment_match_missing_assigment_not_applicable() {
+    fn pull_assignment_up_match_missing_assigment_not_applicable() {
        check_assist_not_applicable(
-            extract_assigment,
+            pull_assignment_up,
            r#"
 fn foo() {
    let mut a = 1;
@@ -367,10 +367,10 @@ fn foo() {
    }
    #[test]
-    fn test_extract_assignment_field_assignment() {
+    fn test_pull_assignment_up_field_assignment() {
-        mark::check!(test_extract_assignment_field_assignment);
+        mark::check!(test_pull_assignment_up_field_assignment);
        check_assist(
-            extract_assigment,
+            pull_assignment_up,
            r#"
 struct A(usize);
diff --git a/crates/assists/src/lib.rs b/crates/assists/src/lib.rs
index 212464f85..01baa65fe 100644
--- a/crates/assists/src/lib.rs
+++ b/crates/assists/src/lib.rs
@@ -116,7 +116,6 @@ mod handlers {
    mod convert_integer_literal;
    mod early_return;
    mod expand_glob_import;
-    mod extract_assignment;
    mod extract_module_to_file;
    mod extract_struct_from_enum_variant;
    mod extract_variable;
@@ -125,8 +124,8 @@ mod handlers {
    mod flip_binexpr;
    mod flip_comma;
    mod flip_trait_bound;
-    mod generate_derive;
    mod generate_default_from_enum_variant;
+    mod generate_derive;
    mod generate_from_impl_for_enum;
    mod generate_function;
    mod generate_impl;
@@ -139,6 +138,7 @@ mod handlers {
    mod merge_match_arms;
    mod move_bounds;
    mod move_guard;
+    mod pull_assignment_up;
    mod qualify_path;
    mod raw_string;
    mod remove_dbg;
@@ -168,7 +168,6 @@ mod handlers {
            convert_integer_literal::convert_integer_literal,
            early_return::convert_to_guarded_return,
            expand_glob_import::expand_glob_import,
-            extract_assignment::extract_assigment,
            extract_module_to_file::extract_module_to_file,
            extract_struct_from_enum_variant::extract_struct_from_enum_variant,
            extract_variable::extract_variable,
@@ -177,8 +176,8 @@ mod handlers {
            flip_binexpr::flip_binexpr,
            flip_comma::flip_comma,
            flip_trait_bound::flip_trait_bound,
-            generate_derive::generate_derive,
            generate_default_from_enum_variant::generate_default_from_enum_variant,
+            generate_derive::generate_derive,
            generate_from_impl_for_enum::generate_from_impl_for_enum,
            generate_function::generate_function,
            generate_impl::generate_impl,
@@ -192,6 +191,7 @@ mod handlers {
            move_bounds::move_bounds_to_where_clause,
            move_guard::move_arm_cond_to_match_guard,
            move_guard::move_guard_to_arm_body,
+            pull_assignment_up::pull_assignment_up,
            qualify_path::qualify_path,
            raw_string::add_hash,
            raw_string::make_usual_string,
diff --git a/crates/assists/src/tests/generated.rs b/crates/assists/src/tests/generated.rs
index b91a816e8..85e3c6742 100644
--- a/crates/assists/src/tests/generated.rs
+++ b/crates/assists/src/tests/generated.rs
@@ -238,35 +238,6 @@ fn qux(bar: Bar, baz: Baz) {}
 }
 #[test]
-fn doctest_extract_assignment() {
-    check_doc_test(
-        "extract_assignment",
-        r#####"
-fn main() {
-    let mut foo = 6;
-    if true {
-        <|>foo = 5;
-    } else {
-        foo = 4;
-    }
-}
-"#####,
-        r#####"
-fn main() {
-    let mut foo = 6;
-    foo = if true {
-        5
-    } else {
-        4
-    };
-}
-"#####,
-    )
-}
-#[test]
 fn doctest_extract_module_to_file() {
    check_doc_test(
        "extract_module_to_file",
@@ -767,6 +738,35 @@ fn handle(action: Action) {
 }
 #[test]
+fn doctest_pull_assignment_up() {
+    check_doc_test(
+        "pull_assignment_up",
+        r#####"
+fn main() {
+    let mut foo = 6;
+    if true {
+        <|>foo = 5;
+    } else {
+        foo = 4;
+    }
+}
+"#####,
+        r#####"
+fn main() {
+    let mut foo = 6;
+    foo = if true {
+        5
+    } else {
+        4
+    };
+}
+"#####,
+    )
+}
+#[test]
 fn doctest_qualify_path() {
    check_doc_test(
        "qualify_path",
diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
index 62eccf475..071e553a8 100644
--- a/crates/hir/src/code_model.rs
+++ b/crates/hir/src/code_model.rs
@@ -5,9 +5,7 @@ use arrayvec::ArrayVec;
 use base_db::{CrateDisplayName, CrateId, Edition, FileId};
 use either::Either;
 use hir_def::{
-    adt::ReprKind,
+    adt::{ReprKind, StructKind, VariantData},
-    adt::StructKind,
-    adt::VariantData,
    builtin_type::BuiltinType,
    expr::{BindingAnnotation, LabelId, Pat, PatId},
    import_map,
@@ -31,7 +29,7 @@ use hir_expand::{
 };
 use hir_ty::{
    autoderef,
-    display::{HirDisplayError, HirFormatter},
+    display::{write_bounds_like_dyn_trait, HirDisplayError, HirFormatter},
    method_resolution,
    traits::{FnTrait, Solution, SolutionVariables},
    ApplicationTy, BoundVar, CallableDefId, Canonical, DebruijnIndex, FnSig, GenericPredicate,
@@ -1278,6 +1276,18 @@ impl TypeParam {
        }
    }
+    pub fn trait_bounds(self, db: &dyn HirDatabase) -> Vec<Trait> {
+        db.generic_predicates_for_param(self.id)
+            .into_iter()
+            .filter_map(|pred| match &pred.value {
+                hir_ty::GenericPredicate::Implemented(trait_ref) => {
+                    Some(Trait::from(trait_ref.trait_))
+                }
+                _ => None,
+            })
+            .collect()
+    }
    pub fn default(self, db: &dyn HirDatabase) -> Option<Type> {
        let params = db.generic_defaults(self.id.parent);
        let local_idx = hir_ty::param_idx(db, self.id)?;
@@ -1293,6 +1303,20 @@ impl TypeParam {
    }
 }
+impl HirDisplay for TypeParam {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write!(f, "{}", self.name(f.db))?;
+        let bounds = f.db.generic_predicates_for_param(self.id);
+        let substs = Substs::type_params(f.db, self.id.parent);
+        let predicates = bounds.iter().cloned().map(|b| b.subst(&substs)).collect::<Vec<_>>();
+        if !(predicates.is_empty() || f.omit_verbose_types()) {
+            write!(f, ": ")?;
+            write_bounds_like_dyn_trait(&predicates, f)?;
+        }
+        Ok(())
+    }
+}
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct LifetimeParam {
    pub(crate) id: LifetimeParamId,
@@ -1331,6 +1355,12 @@ impl ConstParam {
    pub fn parent(self, _db: &dyn HirDatabase) -> GenericDef {
        self.id.parent.into()
    }
+    pub fn ty(self, db: &dyn HirDatabase) -> Type {
+        let def = self.id.parent;
+        let krate = def.module(db.upcast()).krate;
+        Type::new(db, krate, def, db.const_param_ty(self.id))
+    }
 }
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
diff --git a/crates/hir_ty/Cargo.toml b/crates/hir_ty/Cargo.toml
index 3d1778590..b0a453961 100644
--- a/crates/hir_ty/Cargo.toml
+++ b/crates/hir_ty/Cargo.toml
@@ -17,9 +17,9 @@ ena = "0.14.0"
 log = "0.4.8"
 rustc-hash = "1.1.0"
 scoped-tls = "1"
-chalk-solve = { version = "0.45", default-features = false }
+chalk-solve = { version = "0.47", default-features = false }
-chalk-ir = "0.45"
+chalk-ir = "0.47"
-chalk-recursive = "0.45"
+chalk-recursive = "0.47"
 stdx = { path = "../stdx", version = "0.0.0" }
 hir_def = { path = "../hir_def", version = "0.0.0" }
diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index 0e827a29e..a54225c18 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -595,7 +595,7 @@ impl HirDisplay for FnSig {
    }
 }
-fn write_bounds_like_dyn_trait(
+pub fn write_bounds_like_dyn_trait(
    predicates: &[GenericPredicate],
    f: &mut HirFormatter,
 ) -> Result<(), HirDisplayError> {
diff --git a/crates/ide/src/display/short_label.rs b/crates/ide/src/display/short_label.rs
index ea49d9f97..990f740b8 100644
--- a/crates/ide/src/display/short_label.rs
+++ b/crates/ide/src/display/short_label.rs
@@ -87,6 +87,17 @@ impl ShortLabel for ast::Variant {
    }
 }
+impl ShortLabel for ast::ConstParam {
+    fn short_label(&self) -> Option<String> {
+        let mut buf = "const ".to_owned();
+        buf.push_str(self.name()?.text().as_str());
+        if let Some(type_ref) = self.ty() {
+            format_to!(buf, ": {}", type_ref.syntax());
+        }
+        Some(buf)
+    }
+}
 fn short_label_from_ty<T>(node: &T, ty: Option<ast::Type>, prefix: &str) -> Option<String>
 where
    T: NameOwner + VisibilityOwner,
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
index 2737c900f..f2ad95cb6 100644
--- a/crates/ide/src/hover.rs
+++ b/crates/ide/src/hover.rs
@@ -70,7 +70,7 @@ impl HoverConfig {
 #[derive(Debug, Clone)]
 pub enum HoverAction {
    Runnable(Runnable),
-    Implementaion(FilePosition),
+    Implementation(FilePosition),
    GoToType(Vec<HoverGotoTypeData>),
 }
@@ -116,12 +116,13 @@ pub(crate) fn hover(
    };
    if let Some(definition) = definition {
        if let Some(markup) = hover_for_definition(db, definition) {
+            let markup = markup.as_str();
            let markup = if !markdown {
-                remove_markdown(&markup.as_str())
+                remove_markdown(markup)
            } else if links_in_hover {
-                rewrite_links(db, &markup.as_str(), &definition)
+                rewrite_links(db, markup, &definition)
            } else {
-                remove_links(&markup.as_str())
+                remove_links(markup)
            };
            res.markup = Markup::from(markup);
            if let Some(action) = show_implementations_action(db, definition) {
@@ -175,22 +176,24 @@ pub(crate) fn hover(
 fn show_implementations_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> {
    fn to_action(nav_target: NavigationTarget) -> HoverAction {
-        HoverAction::Implementaion(FilePosition {
+        HoverAction::Implementation(FilePosition {
            file_id: nav_target.file_id,
            offset: nav_target.focus_or_full_range().start(),
        })
    }
-    match def {
+    let adt = match def {
-        Definition::ModuleDef(it) => match it {
+        Definition::ModuleDef(ModuleDef::Trait(it)) => return it.try_to_nav(db).map(to_action),
-            ModuleDef::Adt(Adt::Struct(it)) => Some(to_action(it.try_to_nav(db)?)),
+        Definition::ModuleDef(ModuleDef::Adt(it)) => Some(it),
-            ModuleDef::Adt(Adt::Union(it)) => Some(to_action(it.try_to_nav(db)?)),
+        Definition::SelfType(it) => it.target_ty(db).as_adt(),
-            ModuleDef::Adt(Adt::Enum(it)) => Some(to_action(it.try_to_nav(db)?)),
-            ModuleDef::Trait(it) => Some(to_action(it.try_to_nav(db)?)),
-            _ => None,
-        },
        _ => None,
+    }?;
+    match adt {
+        Adt::Struct(it) => it.try_to_nav(db),
+        Adt::Union(it) => it.try_to_nav(db),
+        Adt::Enum(it) => it.try_to_nav(db),
    }
+    .map(to_action)
 }
 fn runnable_action(
@@ -225,45 +228,46 @@ fn runnable_action(
 }
 fn goto_type_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> {
-    match def {
+    let mut targets: Vec<ModuleDef> = Vec::new();
-        Definition::Local(it) => {
+    let mut push_new_def = |item: ModuleDef| {
-            let mut targets: Vec<ModuleDef> = Vec::new();
+        if !targets.contains(&item) {
-            let mut push_new_def = |item: ModuleDef| {
+            targets.push(item);
-                if !targets.contains(&item) {
-                    targets.push(item);
-                }
-            };
-            it.ty(db).walk(db, |t| {
-                if let Some(adt) = t.as_adt() {
-                    push_new_def(adt.into());
-                } else if let Some(trait_) = t.as_dyn_trait() {
-                    push_new_def(trait_.into());
-                } else if let Some(traits) = t.as_impl_traits(db) {
-                    traits.into_iter().for_each(|it| push_new_def(it.into()));
-                } else if let Some(trait_) = t.as_associated_type_parent_trait(db) {
-                    push_new_def(trait_.into());
-                }
-            });
-            let targets = targets
-                .into_iter()
-                .filter_map(|it| {
-                    Some(HoverGotoTypeData {
-                        mod_path: render_path(
-                            db,
-                            it.module(db)?,
-                            it.name(db).map(|name| name.to_string()),
-                        ),
-                        nav: it.try_to_nav(db)?,
-                    })
-                })
-                .collect();
-            Some(HoverAction::GoToType(targets))
        }
-        _ => None,
+    };
+    if let Definition::TypeParam(it) = def {
+        it.trait_bounds(db).into_iter().for_each(|it| push_new_def(it.into()));
+    } else {
+        let ty = match def {
+            Definition::Local(it) => it.ty(db),
+            Definition::ConstParam(it) => it.ty(db),
+            _ => return None,
+        };
+        ty.walk(db, |t| {
+            if let Some(adt) = t.as_adt() {
+                push_new_def(adt.into());
+            } else if let Some(trait_) = t.as_dyn_trait() {
+                push_new_def(trait_.into());
+            } else if let Some(traits) = t.as_impl_traits(db) {
+                traits.into_iter().for_each(|it| push_new_def(it.into()));
+            } else if let Some(trait_) = t.as_associated_type_parent_trait(db) {
+                push_new_def(trait_.into());
+            }
+        });
    }
+    let targets = targets
+        .into_iter()
+        .filter_map(|it| {
+            Some(HoverGotoTypeData {
+                mod_path: render_path(db, it.module(db)?, it.name(db).map(|name| name.to_string())),
+                nav: it.try_to_nav(db)?,
+            })
+        })
+        .collect();
+    Some(HoverAction::GoToType(targets))
 }
 fn hover_markup(
@@ -370,10 +374,8 @@ fn hover_for_definition(db: &RootDatabase, def: Definition) -> Option<Markup> {
        }
        Definition::Label(it) => Some(Markup::fenced_block(&it.name(db))),
        Definition::LifetimeParam(it) => Some(Markup::fenced_block(&it.name(db))),
-        Definition::TypeParam(_) | Definition::ConstParam(_) => {
+        Definition::TypeParam(type_param) => Some(Markup::fenced_block(&type_param.display(db))),
-            // FIXME: Hover for generic param
+        Definition::ConstParam(it) => from_def_source(db, it, None),
-            None
-        }
    };
    fn from_def_source<A, D>(db: &RootDatabase, def: D, mod_path: Option<String>) -> Option<Markup>
@@ -1393,7 +1395,7 @@ fn bar() { fo<|>o(); }
            r"unsafe trait foo<|>() {}",
            expect![[r#"
                [
-                    Implementaion(
+                    Implementation(
                        FilePosition {
                            file_id: FileId(
                                0,
@@ -2105,7 +2107,7 @@ fn foo() { let bar = Bar; bar.fo<|>o(); }
            r#"trait foo<|>() {}"#,
            expect![[r#"
                [
-                    Implementaion(
+                    Implementation(
                        FilePosition {
                            file_id: FileId(
                                0,
@@ -2124,7 +2126,7 @@ fn foo() { let bar = Bar; bar.fo<|>o(); }
            r"struct foo<|>() {}",
            expect![[r#"
                [
-                    Implementaion(
+                    Implementation(
                        FilePosition {
                            file_id: FileId(
                                0,
@@ -2143,7 +2145,7 @@ fn foo() { let bar = Bar; bar.fo<|>o(); }
            r#"union foo<|>() {}"#,
            expect![[r#"
                [
-                    Implementaion(
+                    Implementation(
                        FilePosition {
                            file_id: FileId(
                                0,
@@ -2162,7 +2164,7 @@ fn foo() { let bar = Bar; bar.fo<|>o(); }
            r"enum foo<|>() { A, B }",
            expect![[r#"
                [
-                    Implementaion(
+                    Implementation(
                        FilePosition {
                            file_id: FileId(
                                0,
@@ -2176,6 +2178,25 @@ fn foo() { let bar = Bar; bar.fo<|>o(); }
    }
    #[test]
+    fn test_hover_self_has_impl_action() {
+        check_actions(
+            r#"struct foo where Self<|>:;"#,
+            expect![[r#"
+                [
+                    Implementation(
+                        FilePosition {
+                            file_id: FileId(
+                                0,
+                            ),
+                            offset: 7,
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+    #[test]
    fn test_hover_test_has_action() {
        check_actions(
            r#"
@@ -3064,6 +3085,71 @@ fn main() { let s<|>t = test().get(); }
    }
    #[test]
+    fn test_hover_const_param_has_goto_type_action() {
+        check_actions(
+            r#"
+struct Bar;
+struct Foo<const BAR: Bar>;
+impl<const BAR: Bar> Foo<BAR<|>> {}
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "test::Bar",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        0,
+                                    ),
+                                    full_range: 0..11,
+                                    focus_range: 7..10,
+                                    name: "Bar",
+                                    kind: Struct,
+                                    description: "struct Bar",
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+    #[test]
+    fn test_hover_type_param_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+fn foo<T: Foo>(t: T<|>){}
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "test::Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        0,
+                                    ),
+                                    full_range: 0..12,
+                                    focus_range: 6..9,
+                                    name: "Foo",
+                                    kind: Trait,
+                                    description: "trait Foo",
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+    #[test]
    fn hover_displays_normalized_crate_names() {
        check(
            r#"
@@ -3257,4 +3343,68 @@ fn foo() {
            "#]],
        );
    }
+    #[test]
+    fn hover_type_param() {
+        check(
+            r#"
+struct Foo<T>(T);
+trait Copy {}
+trait Clone {}
+trait Sized {}
+impl<T: Copy + Clone> Foo<T<|>> where T: Sized {}
+"#,
+            expect![[r#"
+                *T*
+                ```rust
+                T: Copy + Clone + Sized
+                ```
+            "#]],
+        );
+        check(
+            r#"
+struct Foo<T>(T);
+impl<T> Foo<T<|>> {}
+"#,
+            expect![[r#"
+                *T*
+                ```rust
+                T
+                ```
+                "#]],
+        );
+        // lifetimes aren't being substituted yet
+        check(
+            r#"
+struct Foo<T>(T);
+impl<T: 'static> Foo<T<|>> {}
+"#,
+            expect![[r#"
+                *T*
+                ```rust
+                T: {error}
+                ```
+                "#]],
+        );
+    }
+    #[test]
+    fn hover_const_param() {
+        check(
+            r#"
+struct Foo<const LEN: usize>;
+impl<const LEN: usize> Foo<LEN<|>> {}
+"#,
+            expect![[r#"
+                *LEN*
+                ```rust
+                const LEN: usize
+                ```
+            "#]],
+        );
+    }
 }
diff --git a/crates/parser/src/grammar.rs b/crates/parser/src/grammar.rs
index 63cc90027..bb9ffea8b 100644
--- a/crates/parser/src/grammar.rs
+++ b/crates/parser/src/grammar.rs
@@ -66,6 +66,10 @@ pub(crate) mod fragments {
        expressions::stmt(p, expressions::StmtWithSemi::No)
    }
+    pub(crate) fn stmt_optional_semi(p: &mut Parser) {
+        expressions::stmt(p, expressions::StmtWithSemi::Optional)
+    }
    pub(crate) fn opt_visibility(p: &mut Parser) {
        let _ = super::opt_visibility(p);
    }
diff --git a/crates/parser/src/lib.rs b/crates/parser/src/lib.rs
index 811e740f9..9dfe63028 100644
--- a/crates/parser/src/lib.rs
+++ b/crates/parser/src/lib.rs
@@ -88,6 +88,7 @@ pub enum FragmentKind {
    Path,
    Expr,
    Statement,
+    StatementOptionalSemi,
    Type,
    Pattern,
    Item,
@@ -118,6 +119,7 @@ pub fn parse_fragment(
        FragmentKind::Visibility => grammar::fragments::opt_visibility,
        FragmentKind::MetaItem => grammar::fragments::meta_item,
        FragmentKind::Statement => grammar::fragments::stmt,
+        FragmentKind::StatementOptionalSemi => grammar::fragments::stmt_optional_semi,
        FragmentKind::Items => grammar::fragments::macro_items,
        FragmentKind::Statements => grammar::fragments::macro_stmts,
        FragmentKind::Attr => grammar::fragments::attr,
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index dd486070b..c21ca044a 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -1648,7 +1648,7 @@ fn prepare_hover_actions(
    actions
        .iter()
        .filter_map(|it| match it {
-            HoverAction::Implementaion(position) => show_impl_command_link(snap, position),
+            HoverAction::Implementation(position) => show_impl_command_link(snap, position),
            HoverAction::Runnable(r) => runnable_action_links(snap, file_id, r.clone()),
            HoverAction::GoToType(targets) => goto_type_action_links(snap, targets),
        })
diff --git a/crates/ssr/src/parsing.rs b/crates/ssr/src/parsing.rs
index f3b084baf..289affe90 100644
--- a/crates/ssr/src/parsing.rs
+++ b/crates/ssr/src/parsing.rs
@@ -78,6 +78,7 @@ impl ParsedRule {
        builder.try_add(ast::Item::parse(&raw_pattern), raw_template.map(ast::Item::parse));
        builder.try_add(ast::Path::parse(&raw_pattern), raw_template.map(ast::Path::parse));
        builder.try_add(ast::Pat::parse(&raw_pattern), raw_template.map(ast::Pat::parse));
+        builder.try_add(ast::Stmt::parse(&raw_pattern), raw_template.map(ast::Stmt::parse));
        builder.build()
    }
 }
diff --git a/crates/ssr/src/tests.rs b/crates/ssr/src/tests.rs
index 63131f6ca..c4149a849 100644
--- a/crates/ssr/src/tests.rs
+++ b/crates/ssr/src/tests.rs
@@ -160,6 +160,50 @@ fn assert_match_failure_reason(pattern: &str, code: &str, snippet: &str, expecte
 }
 #[test]
+fn ssr_let_stmt_in_macro_match() {
+    assert_matches(
+        "let a = 0",
+        r#"
+            macro_rules! m1 { ($a:stmt) => {$a}; }
+            fn f() {m1!{ let a = 0 };}"#,
+        // FIXME: Whitespace is not part of the matched block
+        &["leta=0"],
+    );
+}
+#[test]
+fn ssr_let_stmt_in_fn_match() {
+    assert_matches("let $a = 10;", "fn main() { let x = 10; x }", &["let x = 10;"]);
+    assert_matches("let $a = $b;", "fn main() { let x = 10; x }", &["let x = 10;"]);
+}
+#[test]
+fn ssr_block_expr_match() {
+    assert_matches("{ let $a = $b; }", "fn main() { let x = 10; }", &["{ let x = 10; }"]);
+    assert_matches("{ let $a = $b; $c }", "fn main() { let x = 10; x }", &["{ let x = 10; x }"]);
+}
+#[test]
+fn ssr_let_stmt_replace() {
+    // Pattern and template with trailing semicolon
+    assert_ssr_transform(
+        "let $a = $b; ==>> let $a = 11;",
+        "fn main() { let x = 10; x }",
+        expect![["fn main() { let x = 11; x }"]],
+    );
+}
+#[test]
+fn ssr_let_stmt_replace_expr() {
+    // Trailing semicolon should be dropped from the new expression
+    assert_ssr_transform(
+        "let $a = $b; ==>> $b",
+        "fn main() { let x = 10; }",
+        expect![["fn main() { 10 }"]],
+    );
+}
+#[test]
 fn ssr_function_to_method() {
    assert_ssr_transform(
        "my_function($a, $b) ==>> ($a).my_method($b)",
diff --git a/crates/syntax/Cargo.toml b/crates/syntax/Cargo.toml
index 181077944..cfeaed9e6 100644
--- a/crates/syntax/Cargo.toml
+++ b/crates/syntax/Cargo.toml
@@ -13,7 +13,7 @@ doctest = false
 [dependencies]
 itertools = "0.10.0"
 rowan = "0.10.0"
-rustc_lexer = { version = "695.0.0", package = "rustc-ap-rustc_lexer" }
+rustc_lexer = { version = "697.0.0", package = "rustc-ap-rustc_lexer" }
 rustc-hash = "1.1.0"
 arrayvec = "0.5.1"
 once_cell = "1.3.1"
diff --git a/crates/syntax/src/lib.rs b/crates/syntax/src/lib.rs
index 4d272f367..da151e328 100644
--- a/crates/syntax/src/lib.rs
+++ b/crates/syntax/src/lib.rs
@@ -212,6 +212,13 @@ impl ast::Attr {
    }
 }
+impl ast::Stmt {
+    /// Returns `text`, parsed as statement, but only if it has no errors.
+    pub fn parse(text: &str) -> Result<Self, ()> {
+        parsing::parse_text_fragment(text, parser::FragmentKind::StatementOptionalSemi)
+    }
+}
 /// Matches a `SyntaxNode` against an `ast` type.
 ///
 /// # Example:
diff --git a/crates/syntax/src/tests.rs b/crates/syntax/src/tests.rs
index 8c217dfe0..9d3433c9d 100644
--- a/crates/syntax/src/tests.rs
+++ b/crates/syntax/src/tests.rs
@@ -103,6 +103,15 @@ fn type_parser_tests() {
 }
 #[test]
+fn stmt_parser_tests() {
+    fragment_parser_dir_test(
+        &["parser/fragments/stmt/ok"],
+        &["parser/fragments/stmt/err"],
+        crate::ast::Stmt::parse,
+    );
+}
+#[test]
 fn parser_fuzz_tests() {
    for (_, text) in collect_rust_files(&test_data_dir(), &["parser/fuzz-failures"]) {
        fuzz::check_parser(&text)
diff --git a/crates/syntax/test_data/parser/fragments/stmt/err/0000_attr.rast b/crates/syntax/test_data/parser/fragments/stmt/err/0000_attr.rast
new file mode 100644
index 000000000..5df7507e2
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/err/0000_attr.rast
@@ -0,0 +1 @@
+ERROR
diff --git a/crates/syntax/test_data/parser/fragments/stmt/err/0000_attr.rs b/crates/syntax/test_data/parser/fragments/stmt/err/0000_attr.rs
new file mode 100644
index 000000000..988df0705
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/err/0000_attr.rs
@@ -0,0 +1 @@
+#[foo]
diff --git a/crates/syntax/test_data/parser/fragments/stmt/err/0000_multiple_stmts.rast b/crates/syntax/test_data/parser/fragments/stmt/err/0000_multiple_stmts.rast
new file mode 100644
index 000000000..5df7507e2
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/err/0000_multiple_stmts.rast
@@ -0,0 +1 @@
+ERROR
diff --git a/crates/syntax/test_data/parser/fragments/stmt/err/0000_multiple_stmts.rs b/crates/syntax/test_data/parser/fragments/stmt/err/0000_multiple_stmts.rs
new file mode 100644
index 000000000..7e3b2fd49
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/err/0000_multiple_stmts.rs
@@ -0,0 +1 @@
+a(); b(); c()
diff --git a/crates/syntax/test_data/parser/fragments/stmt/err/0000_open_parenthesis.rast b/crates/syntax/test_data/parser/fragments/stmt/err/0000_open_parenthesis.rast
new file mode 100644
index 000000000..5df7507e2
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/err/0000_open_parenthesis.rast
@@ -0,0 +1 @@
+ERROR
diff --git a/crates/syntax/test_data/parser/fragments/stmt/err/0000_open_parenthesis.rs b/crates/syntax/test_data/parser/fragments/stmt/err/0000_open_parenthesis.rs
new file mode 100644
index 000000000..2d06f3766
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/err/0000_open_parenthesis.rs
@@ -0,0 +1 @@
+(
diff --git a/crates/syntax/test_data/parser/fragments/stmt/err/0000_semicolon.rast b/crates/syntax/test_data/parser/fragments/stmt/err/0000_semicolon.rast
new file mode 100644
index 000000000..5df7507e2
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/err/0000_semicolon.rast
@@ -0,0 +1 @@
+ERROR
diff --git a/crates/syntax/test_data/parser/fragments/stmt/err/0000_semicolon.rs b/crates/syntax/test_data/parser/fragments/stmt/err/0000_semicolon.rs
new file mode 100644
index 000000000..092bc2b04
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/err/0000_semicolon.rs
@@ -0,0 +1 @@
+;
diff --git a/crates/syntax/test_data/parser/fragments/stmt/err/0000_unterminated_expr.rast b/crates/syntax/test_data/parser/fragments/stmt/err/0000_unterminated_expr.rast
new file mode 100644
index 000000000..5df7507e2
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/err/0000_unterminated_expr.rast
@@ -0,0 +1 @@
+ERROR
diff --git a/crates/syntax/test_data/parser/fragments/stmt/err/0000_unterminated_expr.rs b/crates/syntax/test_data/parser/fragments/stmt/err/0000_unterminated_expr.rs
new file mode 100644
index 000000000..ca49acb07
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/err/0000_unterminated_expr.rs
@@ -0,0 +1 @@
+1 +
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_expr.rast b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_expr.rast
new file mode 100644
index 000000000..274fdf16d
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_expr.rast
@@ -0,0 +1,9 @@
+[email protected]
+  [email protected]
+    [email protected]
+      [email protected] "1"
+    [email protected] " "
+    [email protected] "+"
+    [email protected] " "
+    [email protected]
+      [email protected] "1"
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_expr.rs b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_expr.rs
new file mode 100644
index 000000000..8d2f0971e
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_expr.rs
@@ -0,0 +1 @@
+1 + 1
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_expr_block.rast b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_expr_block.rast
new file mode 100644
index 000000000..6c946091f
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_expr_block.rast
@@ -0,0 +1,69 @@
+[email protected]
+  [email protected]
+    [email protected] "{"
+    [email protected] "\n    "
+    [email protected]
+      [email protected] "let"
+      [email protected] " "
+      [email protected]
+        [email protected]
+          [email protected] "x"
+      [email protected] " "
+      [email protected] "="
+      [email protected] " "
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "foo"
+        [email protected]
+          [email protected] "("
+          [email protected] ")"
+      [email protected] ";"
+    [email protected] "\n    "
+    [email protected]
+      [email protected] "let"
+      [email protected] " "
+      [email protected]
+        [email protected]
+          [email protected] "y"
+      [email protected] " "
+      [email protected] "="
+      [email protected] " "
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "bar"
+        [email protected]
+          [email protected] "("
+          [email protected] ")"
+      [email protected] ";"
+    [email protected] "\n    "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected] "Ok"
+      [email protected]
+        [email protected] "("
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected] "x"
+          [email protected] " "
+          [email protected] "+"
+          [email protected] " "
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected] "y"
+        [email protected] ")"
+    [email protected] "\n"
+    [email protected] "}"
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_expr_block.rs b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_expr_block.rs
new file mode 100644
index 000000000..ffa5c1e66
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_expr_block.rs
@@ -0,0 +1,5 @@
+{
+    let x = foo();
+    let y = bar();
+    Ok(x + y)
+}
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_fn_call.rast b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_fn_call.rast
new file mode 100644
index 000000000..8c186da93
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_fn_call.rast
@@ -0,0 +1,11 @@
+[email protected]
+  [email protected]
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "foo"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+  [email protected] ";"
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_fn_call.rs b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_fn_call.rs
new file mode 100644
index 000000000..a280f9a5c
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_fn_call.rs
@@ -0,0 +1 @@
+foo();
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_let_stmt.rast b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_let_stmt.rast
new file mode 100644
index 000000000..8ab38da21
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_let_stmt.rast
@@ -0,0 +1,12 @@
+[email protected]
+  [email protected] "let"
+  [email protected] " "
+  [email protected]
+    [email protected]
+      [email protected] "x"
+  [email protected] " "
+  [email protected] "="
+  [email protected] " "
+  [email protected]
+    [email protected] "10"
+  [email protected] ";"
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_let_stmt.rs b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_let_stmt.rs
new file mode 100644
index 000000000..de8a7f1fc
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_let_stmt.rs
@@ -0,0 +1 @@
+let x = 10;
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_macro_let_stmt.rast b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_macro_let_stmt.rast
new file mode 100644
index 000000000..81d6df29a
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_macro_let_stmt.rast
@@ -0,0 +1,21 @@
+[email protected]
+  [email protected]
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected] "m1"
+    [email protected] "!"
+    [email protected]
+      [email protected] "{"
+      [email protected] " "
+      [email protected] "let"
+      [email protected] " "
+      [email protected] "a"
+      [email protected] " "
+      [email protected] "="
+      [email protected] " "
+      [email protected] "0"
+      [email protected] ";"
+      [email protected] " "
+      [email protected] "}"
+  [email protected] ";"
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_macro_let_stmt.rs b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_macro_let_stmt.rs
new file mode 100644
index 000000000..075f30159
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_macro_let_stmt.rs
@@ -0,0 +1 @@
+m1!{ let a = 0; };
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_macro_unterminated_let_stmt.rast b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_macro_unterminated_let_stmt.rast
new file mode 100644
index 000000000..81d6df29a
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_macro_unterminated_let_stmt.rast
@@ -0,0 +1,21 @@
+[email protected]
+  [email protected]
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected] "m1"
+    [email protected] "!"
+    [email protected]
+      [email protected] "{"
+      [email protected] " "
+      [email protected] "let"
+      [email protected] " "
+      [email protected] "a"
+      [email protected] " "
+      [email protected] "="
+      [email protected] " "
+      [email protected] "0"
+      [email protected] ";"
+      [email protected] " "
+      [email protected] "}"
+  [email protected] ";"
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_macro_unterminated_let_stmt.rs b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_macro_unterminated_let_stmt.rs
new file mode 100644
index 000000000..075f30159
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_macro_unterminated_let_stmt.rs
@@ -0,0 +1 @@
+m1!{ let a = 0; };
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_struct_item.rast b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_struct_item.rast
new file mode 100644
index 000000000..64c5d2969
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_struct_item.rast
@@ -0,0 +1,22 @@
+[email protected]
+  [email protected] "struct"
+  [email protected] " "
+  [email protected]
+    [email protected] "Foo"
+  [email protected] " "
+  [email protected]
+    [email protected] "{"
+    [email protected] "\n    "
+    [email protected]
+      [email protected]
+        [email protected] "bar"
+      [email protected] ":"
+      [email protected] " "
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected] "u32"
+    [email protected] ","
+    [email protected] "\n"
+    [email protected] "}"
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_struct_item.rs b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_struct_item.rs
new file mode 100644
index 000000000..e5473e3ac
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_struct_item.rs
@@ -0,0 +1,3 @@
+struct Foo {
+    bar: u32,
+}
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_unterminated_fn_call.rast b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_unterminated_fn_call.rast
new file mode 100644
index 000000000..9089906bc
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_unterminated_fn_call.rast
@@ -0,0 +1,10 @@
+[email protected]
+  [email protected]
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "foo"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_unterminated_fn_call.rs b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_unterminated_fn_call.rs
new file mode 100644
index 000000000..eb28ef440
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_unterminated_fn_call.rs
@@ -0,0 +1 @@
+foo()
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_unterminated_let_stmt.rast b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_unterminated_let_stmt.rast
new file mode 100644
index 000000000..37663671f
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_unterminated_let_stmt.rast
@@ -0,0 +1,11 @@
+[email protected]
+  [email protected] "let"
+  [email protected] " "
+  [email protected]
+    [email protected]
+      [email protected] "x"
+  [email protected] " "
+  [email protected] "="
+  [email protected] " "
+  [email protected]
+    [email protected] "10"
diff --git a/crates/syntax/test_data/parser/fragments/stmt/ok/0000_unterminated_let_stmt.rs b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_unterminated_let_stmt.rs
new file mode 100644
index 000000000..78364b2a9
--- /dev/null
+++ b/crates/syntax/test_data/parser/fragments/stmt/ok/0000_unterminated_let_stmt.rs
@@ -0,0 +1 @@
+let x = 10