PARSE: Parse Const Generics Defaults

Author: mchernyavsky

src/main/grammars/RustParser.bnf

@@ -448,7 +448,7 @@ TypeParameter ::= OuterAttr* identifier TypeParamBounds? DefaultTypeParameterTyp
 }
 private DefaultTypeParameterType ::= '=' TypeReference { pin = 1 }
 
-ConstParameter ::= OuterAttr* const identifier TypeAscription {
+ConstParameter ::= OuterAttr* const identifier TypeAscription DefaultConstParameter? {
   pin = 2
   implements = [ "org.rust.lang.core.psi.ext.RsGenericParameter"
                  "org.rust.lang.core.psi.ext.RsOuterAttributeOwner" ]
@@ -457,6 +457,8 @@ ConstParameter ::= OuterAttr* const identifier TypeAscription {
   elementTypeFactory = "org.rust.lang.core.stubs.StubImplementationsKt.factory"
 }
 
+private DefaultConstParameter ::= '=' BlockExpr { pin = 1 }
+
 private TypeBounds ::= [ Polybound ('+' Polybound)* '+'? ]
 
 TypeParamBounds ::= ':' TypeBounds {

src/main/kotlin/org/rust/lang/core/parser/RustParserDefinition.kt

@@ -104,6 +104,6 @@ class RustParserDefinition : ParserDefinition {
         /**
          * Should be increased after any change of parser rules
          */
-        const val PARSER_VERSION: Int = LEXER_VERSION + 29
+        const val PARSER_VERSION: Int = LEXER_VERSION + 30
     }
 }

src/test/resources/org/rust/lang/core/parser/fixtures/complete/const_generics.rs

@@ -1,3 +1,3 @@
-struct S<T, const N: i32, const M: &'static str>;
-fn foo<T, const N: i32, const M: &'static str>() {}
+struct S<T, const N: i32, const M: &'static str = { "" }>;
+fn foo<T, const N: i32, const M: &'static str = { "" }>() {}
 fn main() { foo::<S<i32, 0, { x }>, -0, "">() }

src/test/resources/org/rust/lang/core/parser/fixtures/complete/const_generics.txt

@@ -34,6 +34,17 @@ FILE
           RsBaseTypeImpl(BASE_TYPE)
             RsPathImpl(PATH)
               PsiElement(identifier)('str')
+        PsiWhiteSpace(' ')
+        PsiElement(=)('=')
+        PsiWhiteSpace(' ')
+        RsBlockExprImpl(BLOCK_EXPR)
+          RsBlockImpl(BLOCK)
+            PsiElement({)('{')
+            PsiWhiteSpace(' ')
+            RsLitExprImpl(LIT_EXPR)
+              PsiElement(STRING_LITERAL)('""')
+            PsiWhiteSpace(' ')
+            PsiElement(})('}')
       PsiElement(>)('>')
     PsiElement(;)(';')
   PsiWhiteSpace('\n')
@@ -72,6 +83,17 @@ FILE
           RsBaseTypeImpl(BASE_TYPE)
             RsPathImpl(PATH)
               PsiElement(identifier)('str')
+        PsiWhiteSpace(' ')
+        PsiElement(=)('=')
+        PsiWhiteSpace(' ')
+        RsBlockExprImpl(BLOCK_EXPR)
+          RsBlockImpl(BLOCK)
+            PsiElement({)('{')
+            PsiWhiteSpace(' ')
+            RsLitExprImpl(LIT_EXPR)
+              PsiElement(STRING_LITERAL)('""')
+            PsiWhiteSpace(' ')
+            PsiElement(})('}')
       PsiElement(>)('>')
     RsValueParameterListImpl(VALUE_PARAMETER_LIST)
       PsiElement(()('(')