3 files changed, 202 insertions, 204 deletions

diff --git a/xtask/src/ast_src.rs b/xtask/src/ast_src.rs
index 3a58217c4..114898e38 100644
--- a/xtask/src/ast_src.rs
+++ b/xtask/src/ast_src.rs
@@ -93,19 +93,19 @@ pub(crate) const KINDS_SRC: KindsSrc = KindsSrc {
     ],
     nodes: &[
         "SOURCE_FILE",
-        "STRUCT_DEF",
-        "UNION_DEF",
-        "ENUM_DEF",
-        "FN_DEF",
+        "STRUCT",
+        "UNION",
+        "ENUM",
+        "FN",
         "RET_TYPE",
         "EXTERN_CRATE",
         "MODULE",
         "USE",
-        "STATIC_DEF",
-        "CONST_DEF",
-        "TRAIT_DEF",
-        "IMPL_DEF",
-        "TYPE_ALIAS_DEF",
+        "STATIC",
+        "CONST",
+        "TRAIT",
+        "IMPL",
+        "TYPE_ALIAS",
         "MACRO_CALL",
         "TOKEN_TREE",
         "MACRO_DEF",
@@ -159,9 +159,9 @@ pub(crate) const KINDS_SRC: KindsSrc = KindsSrc {
         "MATCH_ARM_LIST",
         "MATCH_ARM",
         "MATCH_GUARD",
-        "RECORD_LIT",
-        "RECORD_FIELD_LIST",
-        "RECORD_FIELD",
+        "RECORD_EXPR",
+        "RECORD_EXPR_FIELD_LIST",
+        "RECORD_EXPR_FIELD",
         "EFFECT_EXPR",
         "BOX_EXPR",
         // postfix
@@ -179,12 +179,12 @@ pub(crate) const KINDS_SRC: KindsSrc = KindsSrc {
         "BIN_EXPR",
         "EXTERN_BLOCK",
         "EXTERN_ITEM_LIST",
-        "ENUM_VARIANT",
-        "RECORD_FIELD_DEF_LIST",
-        "RECORD_FIELD_DEF",
-        "TUPLE_FIELD_DEF_LIST",
-        "TUPLE_FIELD_DEF",
-        "ENUM_VARIANT_LIST",
+        "VARIANT",
+        "RECORD_FIELD_LIST",
+        "RECORD_FIELD",
+        "TUPLE_FIELD_LIST",
+        "TUPLE_FIELD",
+        "VARIANT_LIST",
         "ITEM_LIST",
         "ASSOC_ITEM_LIST",
         "ATTR",
@@ -203,7 +203,8 @@ pub(crate) const KINDS_SRC: KindsSrc = KindsSrc {
         "NAME_REF",
         "LET_STMT",
         "EXPR_STMT",
-        "TYPE_PARAM_LIST",
+        "GENERIC_PARAM_LIST",
+        "GENERIC_PARAM",
         "LIFETIME_PARAM",
         "TYPE_PARAM",
         "CONST_PARAM",
@@ -242,14 +243,13 @@ pub(crate) struct AstNodeSrc {
 #[derive(Debug, Eq, PartialEq)]
 pub(crate) enum Field {
     Token(String),
-    Node { name: String, src: FieldSrc },
+    Node { name: String, ty: String, cardinality: Cardinality },
 }
 
 #[derive(Debug, Eq, PartialEq)]
-pub(crate) enum FieldSrc {
-    Shorthand,
-    Optional(String),
-    Many(String),
+pub(crate) enum Cardinality {
+    Optional,
+    Many,
 }
 
 #[derive(Debug)]
diff --git a/xtask/src/codegen/gen_syntax.rs b/xtask/src/codegen/gen_syntax.rs
index c77fc8a8d..45b788bdb 100644
--- a/xtask/src/codegen/gen_syntax.rs
+++ b/xtask/src/codegen/gen_syntax.rs
@@ -13,7 +13,7 @@ use quote::{format_ident, quote};
 use ungrammar::{Grammar, Rule};
 
 use crate::{
-    ast_src::{AstEnumSrc, AstNodeSrc, AstSrc, Field, FieldSrc, KindsSrc, KINDS_SRC},
+    ast_src::{AstEnumSrc, AstNodeSrc, AstSrc, Cardinality, Field, KindsSrc, KINDS_SRC},
     codegen::{self, update, Mode},
     project_root, Result,
 };
@@ -307,7 +307,7 @@ fn generate_syntax_kinds(grammar: KindsSrc<'_>) -> Result<String> {
 
     let ast = quote! {
         #![allow(bad_style, missing_docs, unreachable_pub)]
-        /// The kind of syntax node, e.g. `IDENT`, `USE_KW`, or `STRUCT_DEF`.
+        /// The kind of syntax node, e.g. `IDENT`, `USE_KW`, or `STRUCT`.
         #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
         #[repr(u16)]
         pub enum SyntaxKind {
@@ -431,7 +431,7 @@ fn pluralize(s: &str) -> String {
 
 impl Field {
     fn is_many(&self) -> bool {
-        matches!(self, Field::Node { src: FieldSrc::Many(_), .. })
+        matches!(self, Field::Node { cardinality: Cardinality::Many, .. })
     }
     fn token_kind(&self) -> Option<proc_macro2::TokenStream> {
         match self {
@@ -471,23 +471,18 @@ impl Field {
                     "::" => "coloncolon",
                     "#" => "pound",
                     "?" => "question_mark",
+                    "," => "comma",
                     _ => name,
                 };
                 format_ident!("{}_token", name)
             }
-            Field::Node { name, src } => match src {
-                FieldSrc::Shorthand => format_ident!("{}", to_lower_snake_case(name)),
-                _ => format_ident!("{}", name),
-            },
+            Field::Node { name, .. } => format_ident!("{}", name),
         }
     }
     fn ty(&self) -> proc_macro2::Ident {
         match self {
             Field::Token(_) => format_ident!("SyntaxToken"),
-            Field::Node { name, src } => match src {
-                FieldSrc::Optional(ty) | FieldSrc::Many(ty) => format_ident!("{}", ty),
-                FieldSrc::Shorthand => format_ident!("{}", name),
-            },
+            Field::Node { ty, .. } => format_ident!("{}", ty),
         }
     }
 }
@@ -514,7 +509,7 @@ fn lower(grammar: &Grammar) -> AstSrc {
             }
             None => {
                 let mut fields = Vec::new();
-                lower_rule(&mut fields, grammar, rule);
+                lower_rule(&mut fields, grammar, None, rule);
                 res.nodes.push(AstNodeSrc { doc: Vec::new(), name, traits: Vec::new(), fields });
             }
         }
@@ -542,17 +537,20 @@ fn lower_enum(grammar: &Grammar, rule: &Rule) -> Option<Vec<String>> {
     Some(variants)
 }
 
-fn lower_rule(acc: &mut Vec<Field>, grammar: &Grammar, rule: &Rule) {
-    if lower_comma_list(acc, grammar, rule) {
+fn lower_rule(acc: &mut Vec<Field>, grammar: &Grammar, label: Option<&String>, rule: &Rule) {
+    if lower_comma_list(acc, grammar, label, rule) {
         return;
     }
 
     match rule {
         Rule::Node(node) => {
-            let field = Field::Node { name: grammar[*node].name.clone(), src: FieldSrc::Shorthand };
+            let ty = grammar[*node].name.clone();
+            let name = label.cloned().unwrap_or_else(|| to_lower_snake_case(&ty));
+            let field = Field::Node { name, ty, cardinality: Cardinality::Optional };
             acc.push(field);
         }
         Rule::Token(token) => {
+            assert!(label.is_none());
             let mut name = grammar[*token].name.clone();
             if name != "int_number" && name != "string" {
                 if "[]{}()".contains(&name) {
@@ -564,48 +562,35 @@ fn lower_rule(acc: &mut Vec<Field>, grammar: &Grammar, rule: &Rule) {
         }
         Rule::Rep(inner) => {
             if let Rule::Node(node) = &**inner {
-                let name = grammar[*node].name.clone();
-                let label = pluralize(&to_lower_snake_case(&name));
-                let field = Field::Node { name: label.clone(), src: FieldSrc::Many(name) };
+                let ty = grammar[*node].name.clone();
+                let name = label.cloned().unwrap_or_else(|| pluralize(&to_lower_snake_case(&ty)));
+                let field = Field::Node { name, ty, cardinality: Cardinality::Many };
                 acc.push(field);
                 return;
             }
             todo!("{:?}", rule)
         }
-        Rule::Labeled { label, rule } => {
-            let node = match &**rule {
-                Rule::Rep(inner) | Rule::Opt(inner) => match &**inner {
-                    Rule::Node(node) => node,
-                    _ => todo!("{:?}", rule),
-                },
-                Rule::Node(node) => node,
-                _ => todo!("{:?}", rule),
-            };
-            let field = Field::Node {
-                name: label.clone(),
-                src: match &**rule {
-                    Rule::Rep(_) => FieldSrc::Many(grammar[*node].name.clone()),
-                    _ => FieldSrc::Optional(grammar[*node].name.clone()),
-                },
-            };
-            acc.push(field);
+        Rule::Labeled { label: l, rule } => {
+            assert!(label.is_none());
+            lower_rule(acc, grammar, Some(l), rule);
         }
         Rule::Seq(rules) | Rule::Alt(rules) => {
             for rule in rules {
-                lower_rule(acc, grammar, rule)
+                lower_rule(acc, grammar, label, rule)
             }
         }
-        Rule::Opt(rule) => lower_rule(acc, grammar, rule),
+        Rule::Opt(rule) => lower_rule(acc, grammar, label, rule),
     }
 }
 
-// (T (',' T)* ','?)?
-fn lower_comma_list(acc: &mut Vec<Field>, grammar: &Grammar, rule: &Rule) -> bool {
+// (T (',' T)* ','?)
+fn lower_comma_list(
+    acc: &mut Vec<Field>,
+    grammar: &Grammar,
+    label: Option<&String>,
+    rule: &Rule,
+) -> bool {
     let rule = match rule {
-        Rule::Opt(it) => it,
-        _ => return false,
-    };
-    let rule = match &**rule {
         Rule::Seq(it) => it,
         _ => return false,
     };
@@ -623,9 +608,9 @@ fn lower_comma_list(acc: &mut Vec<Field>, grammar: &Grammar, rule: &Rule) -> boo
         [comma, Rule::Node(n)] if comma == &**trailing_comma && n == node => (),
         _ => return false,
     }
-    let name = grammar[*node].name.clone();
-    let label = pluralize(&to_lower_snake_case(&name));
-    let field = Field::Node { name: label.clone(), src: FieldSrc::Many(name) };
+    let ty = grammar[*node].name.clone();
+    let name = label.cloned().unwrap_or_else(|| pluralize(&to_lower_snake_case(&ty)));
+    let field = Field::Node { name, ty, cardinality: Cardinality::Many };
     acc.push(field);
     true
 }
@@ -659,7 +644,9 @@ fn extract_enums(ast: &mut AstSrc) {
             }
             if to_remove.len() == enm.variants.len() {
                 node.remove_field(to_remove);
-                node.fields.push(Field::Node { name: enm.name.clone(), src: FieldSrc::Shorthand });
+                let ty = enm.name.clone();
+                let name = to_lower_snake_case(&ty);
+                node.fields.push(Field::Node { name, ty, cardinality: Cardinality::Optional });
             }
         }
     }
@@ -670,10 +657,9 @@ fn extract_struct_traits(ast: &mut AstSrc) {
         ("AttrsOwner", &["attrs"]),
         ("NameOwner", &["name"]),
         ("VisibilityOwner", &["visibility"]),
-        ("TypeParamsOwner", &["type_param_list", "where_clause"]),
+        ("GenericParamsOwner", &["generic_param_list", "where_clause"]),
         ("TypeBoundsOwner", &["type_bound_list", "colon_token"]),
         ("ModuleItemOwner", &["items"]),
-        ("TypeAscriptionOwner", &["ascribed_type"]),
         ("LoopBodyOwner", &["label", "loop_body"]),
         ("ArgListOwner", &["arg_list"]),
     ];
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