2 files changed, 46 insertions, 36 deletions

diff --git a/xtask/src/codegen/gen_syntax.rs b/xtask/src/codegen/gen_syntax.rs
index 059538696..e6231ece2 100644
--- a/xtask/src/codegen/gen_syntax.rs
+++ b/xtask/src/codegen/gen_syntax.rs
@@ -590,6 +590,7 @@ fn lower_rule(acc: &mut Vec<Field>, grammar: &Grammar, label: Option<&String>, r
                     | "op"
                     | "index"
                     | "base"
+                    | "value"
             );
             if manually_implemented {
                 return;
diff --git a/xtask/src/codegen/rust.ungram b/xtask/src/codegen/rust.ungram
index b560202a1..2e3b45011 100644
--- a/xtask/src/codegen/rust.ungram
+++ b/xtask/src/codegen/rust.ungram
@@ -1,3 +1,34 @@
+Path =
+  (qualifier:Path '::')? segment:PathSegment
+
+PathSegment =
+  'crate' | 'self' | 'super'
+| '::' NameRef
+| NameRef GenericArgList?
+| NameRef ParamList RetType?
+| '<' PathType ('as' PathType)? '>'
+
+GenericArgList =
+  '::'? '<' (GenericArg (',' GenericArg)* ','?)? '>'
+
+GenericArg =
+  TypeArg
+| AssocTypeArg
+| LifetimeArg
+| ConstArg
+
+TypeArg =
+  Type
+
+AssocTypeArg =
+  NameRef (':' TypeBoundList | '=' Type)
+
+LifetimeArg =
+  'lifetime'
+
+ConstArg =
+  Expr
+
 SourceFile =
   'shebang'?
   Attr*
@@ -215,14 +246,13 @@ Expr =
 | BreakExpr
 | CallExpr
 | CastExpr
+| ClosureExpr
 | ContinueExpr
 | EffectExpr
 | FieldExpr
 | ForExpr
 | IfExpr
 | IndexExpr
-| Label
-| ClosureExpr
 | Literal
 | LoopExpr
 | MacroCall
@@ -240,7 +270,13 @@ Expr =
 | WhileExpr
 
 Literal =
-  Attr* 'int_number'
+  Attr* value:(
+    'int_number' | 'float_number'
+  | 'string' | 'raw_string'
+  | 'byte_string' | 'raw_byte_string'
+  | 'true' | 'false'
+  | 'char' | 'byte'
+  )
 
 PathExpr =
   Attr* Path
@@ -313,7 +349,7 @@ ArgList =
   '(' args:(Expr (',' Expr)* ','?)? ')'
 
 MethodCallExpr =
-  Attr* Expr '.' NameRef TypeArgList? ArgList
+  Attr* Expr '.' NameRef GenericArgList? ArgList
 
 FieldExpr =
   Attr* Expr '.' NameRef
@@ -340,7 +376,7 @@ ForExpr =
 
 WhileExpr =
   Attr* Label? 'while' Condition
-  loop_body:BlockExpr?
+  loop_body:BlockExpr
 
 Label =
   'lifetime'
@@ -418,13 +454,13 @@ SliceType =
   '[' Type ']'
 
 InferType =
-   '_'
+  '_'
 
 FnPointerType =
-   'const'? 'async'? 'unsafe'? Abi? 'fn' ParamList RetType?
+  'const'? 'async'? 'unsafe'? Abi? 'fn' ParamList RetType?
 
 ForType =
-   'for' GenericParamList Type
+  'for' GenericParamList Type
 
 ImplTraitType =
   'impl' TypeBoundList
@@ -433,7 +469,7 @@ DynTraitType =
   'dyn' TypeBoundList
 
 TypeBoundList =
-   bounds:(TypeBound ('+' TypeBound)* '+'?)
+  bounds:(TypeBound ('+' TypeBound)* '+'?)
 
 TypeBound =
   'lifetime'
@@ -513,33 +549,6 @@ MacroStmts =
   statements:Stmt*
   Expr?
 
-Path =
-  (qualifier:Path '::')? segment:PathSegment
-
-PathSegment =
-  '::' | 'crate' | 'self' | 'super'
-| '<' NameRef TypeArgList ParamList RetType PathType '>'
-
-TypeArgList =
-  '::'? '<'
-    TypeArg*
-    LifetimeArg*
-    AssocTypeArg*
-    ConstArg*
-  '>'
-
-TypeArg =
-  Type
-
-AssocTypeArg =
-  NameRef (':' TypeBoundList | '=' Type)
-
-LifetimeArg =
-  'lifetime'
-
-ConstArg =
-  Literal | BlockExpr BlockExpr
-
 Pat =
   OrPat
 | ParenPat