Merge #8853

8853: Tag Self in impls as a TypeAlias r=matklad a=Veykril

bors r+
Fixes #4398

Co-authored-by: Lukas Wirth <[email protected]>

Author: bors[bot]

crates/ide/src/syntax_highlighting/test_data/highlighting.html

@@ -66,11 +66,11 @@
     <span class="keyword">pub</span> <span class="field declaration">y</span><span class="colon">:</span> <span class="builtin_type">i32</span><span class="comma">,</span>
 <span class="brace">}</span>
 
-<span class="keyword">trait</span> <span class="trait declaration">Bar</span> <span class="brace">{</span>
+<span class="keyword">trait</span> <span class="trait declaration">Bar</span> <span class="keyword">where</span> <span class="type_param">Self</span><span class="colon">:</span> <span class="brace">{</span>
     <span class="keyword">fn</span> <span class="function associated declaration trait">bar</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">i32</span><span class="semicolon">;</span>
 <span class="brace">}</span>
 
-<span class="keyword">impl</span> <span class="trait">Bar</span> <span class="keyword">for</span> <span class="struct">Foo</span> <span class="brace">{</span>
+<span class="keyword">impl</span> <span class="trait">Bar</span> <span class="keyword">for</span> <span class="struct">Foo</span> <span class="keyword">where</span> <span class="self_type">Self</span><span class="colon">:</span> <span class="brace">{</span>
     <span class="keyword">fn</span> <span class="function associated declaration trait">bar</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">i32</span> <span class="brace">{</span>
         <span class="self_keyword">self</span><span class="operator">.</span><span class="field">x</span>
     <span class="brace">}</span>

crates/ide/src/syntax_highlighting/tests.rs

@@ -39,11 +39,11 @@ struct Foo {
     pub y: i32,
 }
 
-trait Bar {
+trait Bar where Self: {
     fn bar(&self) -> i32;
 }
 
-impl Bar for Foo {
+impl Bar for Foo where Self: {
     fn bar(&self) -> i32 {
         self.x
     }

crates/rust-analyzer/src/to_proto.rs

@@ -422,7 +422,7 @@ fn semantic_token_type_and_modifiers(
     let type_ = match highlight.tag {
         HlTag::Symbol(symbol) => match symbol {
             SymbolKind::Module => lsp_types::SemanticTokenType::NAMESPACE,
-            SymbolKind::Impl => lsp_types::SemanticTokenType::TYPE,
+            SymbolKind::Impl => semantic_tokens::TYPE_ALIAS,
             SymbolKind::Field => lsp_types::SemanticTokenType::PROPERTY,
             SymbolKind::TypeParam => lsp_types::SemanticTokenType::TYPE_PARAMETER,
             SymbolKind::ConstParam => semantic_tokens::CONST_PARAMETER,