9 files changed, 51 insertions, 76 deletions

diff --git a/crates/ra_cli/src/analysis_stats.rs b/crates/ra_cli/src/analysis_stats.rs
index b481ace9e..8bb524ce3 100644
--- a/crates/ra_cli/src/analysis_stats.rs
+++ b/crates/ra_cli/src/analysis_stats.rs
@@ -31,18 +31,16 @@ pub fn run(verbose: bool, path: &str, only: Option<&str>) -> Result<()> {
 
             for decl in module.declarations(&db) {
                 num_decls += 1;
-                match decl {
-                    ModuleDef::Function(f) => funcs.push(f),
-                    _ => {}
+                if let ModuleDef::Function(f) = decl {
+                    funcs.push(f);
                 }
             }
 
             for impl_block in module.impl_blocks(&db) {
                 for item in impl_block.items(&db) {
                     num_decls += 1;
-                    match item {
-                        ImplItem::Method(f) => funcs.push(f),
-                        _ => {}
+                    if let ImplItem::Method(f) = item {
+                        funcs.push(f);
                     }
                 }
             }
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 9c02b3995..6ee6bd627 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -281,9 +281,8 @@ impl Module {
 
         for impl_block in self.impl_blocks(db) {
             for item in impl_block.items(db) {
-                match item {
-                    crate::ImplItem::Method(f) => f.diagnostics(db, sink),
-                    _ => (),
+                if let crate::ImplItem::Method(f) = item {
+                    f.diagnostics(db, sink);
                 }
             }
         }
diff --git a/crates/ra_hir/src/traits.rs b/crates/ra_hir/src/traits.rs
index 2a7c2b791..967654e97 100644
--- a/crates/ra_hir/src/traits.rs
+++ b/crates/ra_hir/src/traits.rs
@@ -77,13 +77,10 @@ impl TraitItemsIndex {
     pub(crate) fn trait_items_index(db: &impl DefDatabase, module: Module) -> TraitItemsIndex {
         let mut index = TraitItemsIndex { traits_by_def: FxHashMap::default() };
         for decl in module.declarations(db) {
-            match decl {
-                crate::ModuleDef::Trait(tr) => {
-                    for item in tr.trait_data(db).items() {
-                        index.traits_by_def.insert(*item, tr);
-                    }
+            if let crate::ModuleDef::Trait(tr) = decl {
+                for item in tr.trait_data(db).items() {
+                    index.traits_by_def.insert(*item, tr);
                 }
-                _ => {}
             }
         }
         index
diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index e8ae33ead..1723921e6 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -848,28 +848,23 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     }
 
     fn register_obligations_for_call(&mut self, callable_ty: &Ty) {
-        match callable_ty {
-            Ty::Apply(a_ty) => match a_ty.ctor {
-                TypeCtor::FnDef(def) => {
-                    // add obligation for trait implementation, if this is a trait method
-                    // FIXME also register obligations from where clauses from the trait or impl and method
-                    match def {
-                        CallableDef::Function(f) => {
-                            if let Some(trait_) = f.parent_trait(self.db) {
-                                // construct a TraitDef
-                                let substs = a_ty.parameters.prefix(
-                                    trait_.generic_params(self.db).count_params_including_parent(),
-                                );
-                                self.obligations
-                                    .push(Obligation::Trait(TraitRef { trait_, substs }));
-                            }
+        if let Ty::Apply(a_ty) = callable_ty {
+            if let TypeCtor::FnDef(def) = a_ty.ctor {
+                // add obligation for trait implementation, if this is a trait method
+                // FIXME also register obligations from where clauses from the trait or impl and method
+                match def {
+                    CallableDef::Function(f) => {
+                        if let Some(trait_) = f.parent_trait(self.db) {
+                            // construct a TraitDef
+                            let substs = a_ty.parameters.prefix(
+                                trait_.generic_params(self.db).count_params_including_parent(),
+                            );
+                            self.obligations.push(Obligation::Trait(TraitRef { trait_, substs }));
                         }
-                        CallableDef::Struct(_) | CallableDef::EnumVariant(_) => {}
                     }
+                    CallableDef::Struct(_) | CallableDef::EnumVariant(_) => {}
                 }
-                _ => {}
-            },
-            _ => {}
+            }
         }
     }
 
diff --git a/crates/ra_hir/src/ty/method_resolution.rs b/crates/ra_hir/src/ty/method_resolution.rs
index 34817a5ec..646e58aa9 100644
--- a/crates/ra_hir/src/ty/method_resolution.rs
+++ b/crates/ra_hir/src/ty/method_resolution.rs
@@ -192,23 +192,20 @@ fn iterate_trait_method_candidates<T>(
         // iteration
         let mut known_implemented = false;
         for item in data.items() {
-            match item {
-                &TraitItem::Function(m) => {
-                    let sig = m.signature(db);
-                    if name.map_or(true, |name| sig.name() == name) && sig.has_self_param() {
-                        if !known_implemented {
-                            let trait_ref = canonical_trait_ref(db, t, ty.clone());
-                            if db.implements(krate, trait_ref).is_none() {
-                                continue 'traits;
-                            }
-                        }
-                        known_implemented = true;
-                        if let Some(result) = callback(&ty.value, m) {
-                            return Some(result);
+            if let TraitItem::Function(m) = *item {
+                let sig = m.signature(db);
+                if name.map_or(true, |name| sig.name() == name) && sig.has_self_param() {
+                    if !known_implemented {
+                        let trait_ref = canonical_trait_ref(db, t, ty.clone());
+                        if db.implements(krate, trait_ref).is_none() {
+                            continue 'traits;
                         }
                     }
+                    known_implemented = true;
+                    if let Some(result) = callback(&ty.value, m) {
+                        return Some(result);
+                    }
                 }
-                _ => {}
             }
         }
     }
@@ -230,16 +227,13 @@ fn iterate_inherent_methods<T>(
 
     for impl_block in impls.lookup_impl_blocks(&ty.value) {
         for item in impl_block.items(db) {
-            match item {
-                ImplItem::Method(f) => {
-                    let sig = f.signature(db);
-                    if name.map_or(true, |name| sig.name() == name) && sig.has_self_param() {
-                        if let Some(result) = callback(&ty.value, f) {
-                            return Some(result);
-                        }
+            if let ImplItem::Method(f) = item {
+                let sig = f.signature(db);
+                if name.map_or(true, |name| sig.name() == name) && sig.has_self_param() {
+                    if let Some(result) = callback(&ty.value, f) {
+                        return Some(result);
                     }
                 }
-                _ => {}
             }
         }
     }
diff --git a/crates/ra_hir/src/ty/traits/chalk.rs b/crates/ra_hir/src/ty/traits/chalk.rs
index 78440b258..1e4806db0 100644
--- a/crates/ra_hir/src/ty/traits/chalk.rs
+++ b/crates/ra_hir/src/ty/traits/chalk.rs
@@ -211,13 +211,10 @@ fn convert_where_clauses(
             // anyway), otherwise Chalk can easily get into slow situations
             return vec![pred.clone().subst(substs).to_chalk(db)];
         }
-        match pred {
-            GenericPredicate::Implemented(trait_ref) => {
-                if blacklisted_trait(db, trait_ref.trait_) {
-                    continue;
-                }
+        if let GenericPredicate::Implemented(trait_ref) = pred {
+            if blacklisted_trait(db, trait_ref.trait_) {
+                continue;
             }
-            _ => {}
         }
         result.push(pred.clone().subst(substs).to_chalk(db));
     }
diff --git a/crates/ra_ide_api/src/completion/complete_dot.rs b/crates/ra_ide_api/src/completion/complete_dot.rs
index 5bf289c63..0822a0e7e 100644
--- a/crates/ra_ide_api/src/completion/complete_dot.rs
+++ b/crates/ra_ide_api/src/completion/complete_dot.rs
@@ -16,8 +16,8 @@ pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
 
 fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: Ty) {
     for receiver in receiver.autoderef(ctx.db) {
-        match receiver {
-            Ty::Apply(a_ty) => match a_ty.ctor {
+        if let Ty::Apply(a_ty) = receiver {
+            match a_ty.ctor {
                 TypeCtor::Adt(AdtDef::Struct(s)) => {
                     for field in s.fields(ctx.db) {
                         acc.add_field(ctx, field, &a_ty.parameters);
@@ -30,8 +30,7 @@ fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: Ty)
                     }
                 }
                 _ => {}
-            },
-            _ => {}
+            }
         };
     }
 }
diff --git a/crates/ra_lsp_server/tests/heavy_tests/support.rs b/crates/ra_lsp_server/tests/heavy_tests/support.rs
index f952a03a3..955d283dd 100644
--- a/crates/ra_lsp_server/tests/heavy_tests/support.rs
+++ b/crates/ra_lsp_server/tests/heavy_tests/support.rs
@@ -141,15 +141,14 @@ impl Server {
         R::Params: Serialize,
     {
         let actual = self.send_request::<R>(params);
-        match find_mismatch(&expected_resp, &actual) {
-            Some((expected_part, actual_part)) => panic!(
+        if let Some((expected_part, actual_part)) = find_mismatch(&expected_resp, &actual) {
+            panic!(
                 "JSON mismatch\nExpected:\n{}\nWas:\n{}\nExpected part:\n{}\nActual part:\n{}\n",
                 to_string_pretty(&expected_resp).unwrap(),
                 to_string_pretty(&actual).unwrap(),
                 to_string_pretty(expected_part).unwrap(),
                 to_string_pretty(actual_part).unwrap(),
-            ),
-            None => {}
+            );
         }
     }
 
diff --git a/crates/thread_worker/src/lib.rs b/crates/thread_worker/src/lib.rs
index d67e44e38..d8d0d9bf2 100644
--- a/crates/thread_worker/src/lib.rs
+++ b/crates/thread_worker/src/lib.rs
@@ -19,13 +19,10 @@ impl Drop for ScopedThread {
         log::info!(".. {} terminated with {}", name, if res.is_ok() { "ok" } else { "err" });
 
         // escalate panic, but avoid aborting the process
-        match res {
-            Err(e) => {
-                if !thread::panicking() {
-                    panic!(e)
-                }
+        if let Err(e) = res {
+            if !thread::panicking() {
+                panic!(e)
             }
-            _ => (),
         }
     }
 }