1 files changed, 86 insertions, 78 deletions

diff --git a/xtask/src/codegen/rust.ungram b/xtask/src/codegen/rust.ungram
index 449b0242f..ef7c3e50e 100644
--- a/xtask/src/codegen/rust.ungram
+++ b/xtask/src/codegen/rust.ungram
@@ -4,19 +4,19 @@ SourceFile =
   Item*
 
 Item =
-  ConstDef
-| EnumDef
+  Const
+| Enum
 | ExternBlock
 | ExternCrate
-| FnDef
+| Fn
 | ImplDef
 | MacroCall
 | Module
-| StaticDef
-| StructDef
+| Static
+| Struct
 | TraitDef
-| TypeAliasDef
-| UnionDef
+| TypeAlias
+| Union
 | Use
 
 Module =
@@ -42,73 +42,94 @@ UseTree =
 UseTreeList =
   '{' (UseTree (',' UseTree)* ','?)? '}'
 
-FnDef =
- Attr* Visibility? Abi? 'const' 'default' 'async' 'unsafe' 'fn' Name TypeParamList?
- ParamList RetType?
+Fn =
+ Attr* Visibility?
+ 'default'? ('async' | 'const')? 'unsafe'? Abi?
+ 'fn' Name GenericParamList? ParamList RetType?
  WhereClause?
  (body:BlockExpr | ';')
 
+Abi =
+  'extern' 'string'?
+
+ParamList =
+  '('(
+    (Param (',' Param)* ','?)?
+  | SelfParam ','?
+  | SelfParam ',' (Param (',' Param)* ','?)
+  )')'
+
+SelfParam =
+  Attr* (
+    ('&' 'lifetime'?)? 'mut'? 'self'
+  | 'mut'? 'self' ':' ascribed_type:TypeRef
+  )
+
+Param =
+  Attr* Pat (':' ascribed_type:TypeRef)
+| '...'
+
 RetType =
   '->' TypeRef
 
-StructDef =
-  Attr* Visibility? 'struct' Name TypeParamList? (
-    WhereClause?  (RecordFieldDefList | ';')
-  | TupleFieldDefList WhereClause? ';'
-  )
+TypeAlias =
+  Attr* Visibility? 'default'? 'type' Name GenericParamList? (':' TypeBoundList?)? WhereClause?
+  '=' TypeRef ';'
 
-UnionDef =
-  Attr* Visibility? 'union' Name TypeParamList? WhereClause?
-  RecordFieldDefList
+Struct =
+  Attr* Visibility? 'struct' Name GenericParamList? (
+    WhereClause?  (RecordFieldList | ';')
+  | TupleFieldList WhereClause? ';'
+  )
 
-RecordFieldDefList =
- '{' fields:RecordFieldDef* '}'
+RecordFieldList =
+ '{' fields:(RecordField (',' RecordField)* ','?)? '}'
 
-RecordFieldDef =
+RecordField =
   Attr* Visibility? Name ':' ascribed_type:TypeRef
 
-TupleFieldDefList =
-  '(' fields:TupleFieldDef* ')'
+TupleFieldList =
+  '(' fields:(TupleField (',' TupleField)* ','?)? ')'
+
+TupleField =
+  Attr* Visibility? TypeRef
 
-TupleFieldDef =
-  Attr* Visibility? Name TypeRef
+FieldList =
+  RecordFieldList
+| TupleFieldList
 
-FieldDefList =
-  RecordFieldDefList
-| TupleFieldDefList
+Enum =
+  Attr* Visibility? 'enum' Name GenericParamList? WhereClause?
+  VariantList
 
-EnumDef =
-  Attr* Visibility? 'enum' Name TypeParamList? WhereClause?
-  variant_list:EnumVariantList
+VariantList =
+ '{' (Variant (',' Variant)* ','?)? '}'
 
-EnumVariantList =
- '{' variants:EnumVariant* '}'
+Variant =
+  Attr* Visibility? Name FieldList ('=' Expr)?
 
-EnumVariant =
-  Attr* Visibility? Name FieldDefList ('=' Expr)?
+Union =
+  Attr* Visibility? 'union' Name GenericParamList? WhereClause?
+  RecordFieldList
+
+Const =
+  Attr* Visibility? 'default'? 'const' (Name | '_') ':' ascribed_type:TypeRef
+  '=' body:Expr ';'
+
+Static =
+  Attr* Visibility? 'static'? 'mut'? Name ':' ascribed_type:TypeRef
+  '=' body:Expr ';'
 
 TraitDef =
-  Attr* Visibility? 'unsafe'? 'auto'? 'trait' Name TypeParamList
+  Attr* Visibility? 'unsafe'? 'auto'? 'trait' Name GenericParamList
   (':' TypeBoundList?)? WhereClause
   AssocItemList
 
 AssocItemList =
   '{' AssocItem* '}'
 
-ConstDef =
-  Attr* Visibility? 'default'? 'const' Name ':' ascribed_type:TypeRef
-  '=' body:Expr ';'
-
-StaticDef =
-  Attr* Visibility? 'static'? 'mut'? 'static' Name ':' ascribed_type:TypeRef
-  '=' body:Expr ';'
-
-TypeAliasDef =
-  Attr* Visibility? 'default'? 'type' Name TypeParamList? WhereClause? (':' TypeBoundList?)?
-  '=' TypeRef ';'
-
 ImplDef =
- Attr* Visibility? 'const'? 'default'? 'unsafe'? 'impl' TypeParamList? '!'? 'for'
+ Attr* Visibility? 'const'? 'default'? 'unsafe'? 'impl' GenericParamList? '!'? 'for'
  WhereClause?
  AssocItemList
 
@@ -143,7 +164,7 @@ FnPointerType =
    Abi 'unsafe'? 'fn' ParamList RetType?
 
 ForType =
-   'for' TypeParamList TypeRef
+   'for' GenericParamList TypeRef
 
 ImplTraitType =
   'impl' TypeBoundList
@@ -263,16 +284,16 @@ MatchArm =
 MatchGuard =
   'if' Expr
 
-RecordLit =
- Path RecordFieldList
+RecordExpr =
+ Path RecordExprFieldList
 
-RecordFieldList =
+RecordExprFieldList =
   '{'
-    fields:RecordField*
+    fields:RecordExprField*
     ('..' spread:Expr)?
   '}'
 
-RecordField =
+RecordExprField =
   Attr* NameRef (':' Expr)?
 
 OrPat =
@@ -358,7 +379,7 @@ MacroStmts =
 Attr =
   '#' '!'? '[' Path ('=' input:AttrInput)? ']'
 
-TypeParamList =
+GenericParamList =
   '<'
     TypeParam*
     LifetimeParam*
@@ -383,14 +404,11 @@ TypeBoundList =
    bounds:TypeBound*
 
 WherePred =
-  ('for' TypeParamList)?  ('lifetime' | TypeRef) ':' TypeBoundList
+  ('for' GenericParamList)?  ('lifetime' | TypeRef) ':' TypeBoundList
 
 WhereClause =
   'where' predicates:WherePred*
 
-Abi =
-  'string'
-
 ExprStmt =
   Attr* Expr ';'
 
@@ -398,16 +416,6 @@ LetStmt =
   Attr* 'let' Pat (':' ascribed_type:TypeRef)
   '=' initializer:Expr ';'
 
-ParamList =
-  '(' SelfParam Param* ')'
-
-SelfParam =
-  Attr* ('&' 'lifetime'?)? 'mut'? 'self' (':' ascribed_type:TypeRef)
-
-Param =
-  Attr* Pat (':' ascribed_type:TypeRef)
-| '...'
-
 Path =
   (qualifier:Path '::')? segment:PathSegment
 
@@ -445,9 +453,9 @@ MetaItem =
   Path '=' AttrInput nested_meta_items:MetaItem*
 
 AdtDef =
-  StructDef
-| EnumDef
-| UnionDef
+  Struct
+| Enum
+| Union
 
 TypeRef =
   ParenType
@@ -465,13 +473,13 @@ TypeRef =
 | DynTraitType
 
 AssocItem =
-  FnDef
-| TypeAliasDef
-| ConstDef
+  Fn
+| TypeAlias
+| Const
 | MacroCall
 
 ExternItem =
-  FnDef | StaticDef
+  Fn | Static
 
 AttrInput =
   Literal
@@ -514,7 +522,7 @@ Expr =
 | BlockExpr
 | ReturnExpr
 | MatchExpr
-| RecordLit
+| RecordExpr
 | CallExpr
 | IndexExpr
 | MethodCallExpr