1 files changed, 143 insertions, 131 deletions

diff --git a/xtask/src/codegen/rust.ungram b/xtask/src/codegen/rust.ungram
index 449b0242f..375df301f 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
-| ImplDef
+| Fn
+| Impl
 | MacroCall
 | Module
-| StaticDef
-| StructDef
-| TraitDef
-| TypeAliasDef
-| UnionDef
+| Static
+| Struct
+| Trait
+| TypeAlias
+| Union
 | Use
 
 Module =
@@ -42,78 +42,149 @@ 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 =
+  '('(
+    SelfParam
+  | (SelfParam ',')? (Param (',' Param)* ','?)?
+  )')'
+
+SelfParam =
+  Attr* (
+    ('&' 'lifetime'?)? 'mut'? 'self'
+  | 'mut'? 'self' ':' ty:TypeRef
+  )
+
+Param =
+  Attr* (
+    Pat (':' ty:TypeRef)
+  | ty:TypeRef
+  | '...'
+  )
+
 RetType =
-  '->' TypeRef
+  '->' ty:TypeRef
+
+TypeAlias =
+  Attr* Visibility? 'default'? 'type' Name GenericParamList? (':' TypeBoundList?)? WhereClause?
+  '=' ty:TypeRef ';'
 
-StructDef =
-  Attr* Visibility? 'struct' Name TypeParamList? (
-    WhereClause?  (RecordFieldDefList | ';')
-  | TupleFieldDefList WhereClause? ';'
+Struct =
+  Attr* Visibility? 'struct' Name GenericParamList? (
+    WhereClause?  (RecordFieldList | ';')
+  | TupleFieldList WhereClause? ';'
   )
 
-UnionDef =
-  Attr* Visibility? 'union' Name TypeParamList? WhereClause?
-  RecordFieldDefList
+RecordFieldList =
+ '{' fields:(RecordField (',' RecordField)* ','?)? '}'
+
+RecordField =
+  Attr* Visibility? Name ':' ty:TypeRef
 
-RecordFieldDefList =
- '{' fields:RecordFieldDef* '}'
+TupleFieldList =
+  '(' fields:(TupleField (',' TupleField)* ','?)? ')'
 
-RecordFieldDef =
-  Attr* Visibility? Name ':' ascribed_type:TypeRef
+TupleField =
+  Attr* Visibility? ty:TypeRef
 
-TupleFieldDefList =
-  '(' fields:TupleFieldDef* ')'
+FieldList =
+  RecordFieldList
+| TupleFieldList
 
-TupleFieldDef =
-  Attr* Visibility? Name TypeRef
+Enum =
+  Attr* Visibility? 'enum' Name GenericParamList? WhereClause?
+  VariantList
 
-FieldDefList =
-  RecordFieldDefList
-| TupleFieldDefList
+VariantList =
+ '{' (Variant (',' Variant)* ','?)? '}'
 
-EnumDef =
-  Attr* Visibility? 'enum' Name TypeParamList? WhereClause?
-  variant_list:EnumVariantList
+Variant =
+  Attr* Visibility? Name FieldList ('=' Expr)?
 
-EnumVariantList =
- '{' variants:EnumVariant* '}'
+Union =
+  Attr* Visibility? 'union' Name GenericParamList? WhereClause?
+  RecordFieldList
+
+Const =
+  Attr* Visibility? 'default'? 'const' (Name | '_') ':' ty:TypeRef
+  '=' body:Expr ';'
 
-EnumVariant =
-  Attr* Visibility? Name FieldDefList ('=' Expr)?
+Static =
+  Attr* Visibility? 'static'? 'mut'? Name ':' ty:TypeRef
+  '=' body:Expr ';'
 
-TraitDef =
-  Attr* Visibility? 'unsafe'? 'auto'? 'trait' Name TypeParamList
+Trait =
+  Attr* Visibility? 'unsafe'? 'auto'? 'trait' Name GenericParamList
   (':' TypeBoundList?)? WhereClause
   AssocItemList
 
 AssocItemList =
-  '{' AssocItem* '}'
+  '{' Attr* AssocItem* '}'
 
-ConstDef =
-  Attr* Visibility? 'default'? 'const' Name ':' ascribed_type:TypeRef
-  '=' body:Expr ';'
+AssocItem =
+  Fn
+| TypeAlias
+| Const
+| MacroCall
 
-StaticDef =
-  Attr* Visibility? 'static'? 'mut'? 'static' Name ':' ascribed_type:TypeRef
-  '=' body:Expr ';'
+Impl =
+ Attr* Visibility?
+ 'default'? 'unsafe'? 'impl' 'const'? GenericParamList? (
+   TypeRef
+ | '!'? TypeRef 'for' TypeRef
+ ) WhereClause?
+ AssocItemList
 
-TypeAliasDef =
-  Attr* Visibility? 'default'? 'type' Name TypeParamList? WhereClause? (':' TypeBoundList?)?
-  '=' TypeRef ';'
+ExternBlock =
+  Attr* Abi ExternItemList
 
-ImplDef =
- Attr* Visibility? 'const'? 'default'? 'unsafe'? 'impl' TypeParamList? '!'? 'for'
- WhereClause?
- AssocItemList
+ExternItemList =
+  '{' Attr* ExternItem* '}'
+
+ExternItem =
+  Fn | Static | MacroCall
+
+GenericParamList =
+  '<' (GenericParam (',' GenericParam)* ','?)? '>'
+
+GenericParam =
+  LifetimeParam
+| TypeParam
+| ConstParam
+
+TypeParam =
+  Attr* Name (':' TypeBoundList?)?
+  ('=' default_type:TypeRef)?
+
+ConstParam =
+  Attr* 'const' Name ':' ty:TypeRef
+  ('=' default_val:Expr)?
+
+LifetimeParam =
+  Attr* 'lifetime'
+
+Visibility =
+  'pub' ('('
+    'super'
+  | 'self'
+  | 'crate'
+  | 'in' Path
+  ')')?
+
+Attr =
+  '#' '!'? '[' Path ('=' Literal | TokenTree)? ']'
 
 ParenType =
-  '(' TypeRef ')'
+  '(' ty:TypeRef ')'
 
 TupleType =
   '(' fields:TypeRef* ')'
@@ -125,16 +196,16 @@ PathType =
   Path
 
 PointerType =
-  '*' ('const' | 'mut') TypeRef
+  '*' ('const' | 'mut') ty:TypeRef
 
 ArrayType =
-  '[' TypeRef ';' Expr ']'
+  '[' ty:TypeRef ';' Expr ']'
 
 SliceType =
-  '[' TypeRef ']'
+  '[' ty:TypeRef ']'
 
 ReferenceType =
-  '&' 'lifetime'? 'mut'? TypeRef
+  '&' 'lifetime'? 'mut'? ty:TypeRef
 
 PlaceholderType =
    '_'
@@ -143,7 +214,7 @@ FnPointerType =
    Abi 'unsafe'? 'fn' ParamList RetType?
 
 ForType =
-   'for' TypeParamList TypeRef
+   'for' GenericParamList ty:TypeRef
 
 ImplTraitType =
   'impl' TypeBoundList
@@ -231,7 +302,7 @@ TryExpr =
   Attr* Expr '?'
 
 CastExpr =
-  Attr* Expr 'as' TypeRef
+  Attr* Expr 'as' ty:TypeRef
 
 RefExpr =
   Attr* '&' ('raw' | 'mut' | 'const') Expr
@@ -263,16 +334,16 @@ MatchArm =
 MatchGuard =
   'if' Expr
 
-RecordLit =
- Path RecordFieldList
+RecordExpr =
+ Path RecordExprFieldList
 
-RecordFieldList =
+RecordExprFieldList =
   '{'
-    fields:RecordField*
+    fields:RecordExprField*
     ('..' spread:Expr)?
   '}'
 
-RecordField =
+RecordExprField =
   Attr* NameRef (':' Expr)?
 
 OrPat =
@@ -330,9 +401,6 @@ TupleStructPat =
 TuplePat =
    '(' args:Pat* ')'
 
-Visibility =
-  'pub' ('(' 'super' | 'self' | 'crate' | 'in' Path ')')?
-
 Name =
   'ident'
 
@@ -355,27 +423,6 @@ MacroStmts =
   statements:Stmt*
   Expr?
 
-Attr =
-  '#' '!'? '[' Path ('=' input:AttrInput)? ']'
-
-TypeParamList =
-  '<'
-    TypeParam*
-    LifetimeParam*
-    ConstParam*
-  '>'
-
-TypeParam =
-  Attr* Name (':' TypeBoundList?)?
-  ('=' default_type:TypeRef)?
-
-ConstParam =
-  Attr* 'const' Name ':' ascribed_type:TypeRef
-  ('=' default_val:Expr)?
-
-LifetimeParam =
-  Attr* 'lifetime'
-
 TypeBound =
   'lifetime' | 'const'? TypeRef
 
@@ -383,31 +430,18 @@ TypeBoundList =
    bounds:TypeBound*
 
 WherePred =
-  ('for' TypeParamList)?  ('lifetime' | TypeRef) ':' TypeBoundList
+  ('for' GenericParamList)?  ('lifetime' | TypeRef) ':' TypeBoundList
 
 WhereClause =
   'where' predicates:WherePred*
 
-Abi =
-  'string'
-
 ExprStmt =
   Attr* Expr ';'
 
 LetStmt =
-  Attr* 'let' Pat (':' ascribed_type:TypeRef)
+  Attr* 'let' Pat (':' ty: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
 
@@ -435,19 +469,10 @@ LifetimeArg =
 ConstArg =
   Literal | BlockExpr BlockExpr
 
-ExternBlock =
-  Attr* Abi ExternItemList
-
-ExternItemList =
-  '{' extern_items:ExternItem* '}'
-
-MetaItem =
-  Path '=' AttrInput nested_meta_items:MetaItem*
-
 AdtDef =
-  StructDef
-| EnumDef
-| UnionDef
+  Struct
+| Enum
+| Union
 
 TypeRef =
   ParenType
@@ -464,19 +489,6 @@ TypeRef =
 | ImplTraitType
 | DynTraitType
 
-AssocItem =
-  FnDef
-| TypeAliasDef
-| ConstDef
-| MacroCall
-
-ExternItem =
-  FnDef | StaticDef
-
-AttrInput =
-  Literal
-| TokenTree
-
 Stmt =
   LetStmt
 | ExprStmt
@@ -514,7 +526,7 @@ Expr =
 | BlockExpr
 | ReturnExpr
 | MatchExpr
-| RecordLit
+| RecordExpr
 | CallExpr
 | IndexExpr
 | MethodCallExpr