5 files changed, 170 insertions, 103 deletions

diff --git a/crates/ra_parser/src/syntax_kind/generated.rs b/crates/ra_parser/src/syntax_kind/generated.rs
index d1b22f08a..be4da67bc 100644
--- a/crates/ra_parser/src/syntax_kind/generated.rs
+++ b/crates/ra_parser/src/syntax_kind/generated.rs
@@ -231,6 +231,7 @@ pub enum SyntaxKind {
     LET_STMT,
     EXPR_STMT,
     GENERIC_PARAM_LIST,
+    GENERIC_PARAM,
     LIFETIME_PARAM,
     TYPE_PARAM,
     CONST_PARAM,
diff --git a/crates/ra_syntax/src/ast/generated/nodes.rs b/crates/ra_syntax/src/ast/generated/nodes.rs
index 9345a5e8f..e3b3f44cc 100644
--- a/crates/ra_syntax/src/ast/generated/nodes.rs
+++ b/crates/ra_syntax/src/ast/generated/nodes.rs
@@ -312,9 +312,7 @@ pub struct GenericParamList {
 }
 impl GenericParamList {
     pub fn l_angle_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![<]) }
-    pub fn type_params(&self) -> AstChildren<TypeParam> { support::children(&self.syntax) }
-    pub fn lifetime_params(&self) -> AstChildren<LifetimeParam> { support::children(&self.syntax) }
-    pub fn const_params(&self) -> AstChildren<ConstParam> { support::children(&self.syntax) }
+    pub fn generic_params(&self) -> AstChildren<GenericParam> { support::children(&self.syntax) }
     pub fn r_angle_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![>]) }
 }
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
@@ -470,6 +468,40 @@ impl ExternItemList {
     pub fn r_curly_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T!['}']) }
 }
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct LifetimeParam {
+    pub(crate) syntax: SyntaxNode,
+}
+impl ast::AttrsOwner for LifetimeParam {}
+impl LifetimeParam {
+    pub fn lifetime_token(&self) -> Option<SyntaxToken> {
+        support::token(&self.syntax, T![lifetime])
+    }
+}
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct TypeParam {
+    pub(crate) syntax: SyntaxNode,
+}
+impl ast::AttrsOwner for TypeParam {}
+impl ast::NameOwner for TypeParam {}
+impl ast::TypeBoundsOwner for TypeParam {}
+impl TypeParam {
+    pub fn eq_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![=]) }
+    pub fn default_type(&self) -> Option<TypeRef> { support::child(&self.syntax) }
+}
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct ConstParam {
+    pub(crate) syntax: SyntaxNode,
+}
+impl ast::AttrsOwner for ConstParam {}
+impl ast::NameOwner for ConstParam {}
+impl ast::TypeAscriptionOwner for ConstParam {}
+impl ConstParam {
+    pub fn const_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![const]) }
+    pub fn colon_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![:]) }
+    pub fn eq_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![=]) }
+    pub fn default_val(&self) -> Option<Expr> { support::child(&self.syntax) }
+}
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct ParenType {
     pub(crate) syntax: SyntaxNode,
 }
@@ -1133,40 +1165,6 @@ impl MacroStmts {
     pub fn expr(&self) -> Option<Expr> { support::child(&self.syntax) }
 }
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct TypeParam {
-    pub(crate) syntax: SyntaxNode,
-}
-impl ast::AttrsOwner for TypeParam {}
-impl ast::NameOwner for TypeParam {}
-impl ast::TypeBoundsOwner for TypeParam {}
-impl TypeParam {
-    pub fn eq_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![=]) }
-    pub fn default_type(&self) -> Option<TypeRef> { support::child(&self.syntax) }
-}
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct LifetimeParam {
-    pub(crate) syntax: SyntaxNode,
-}
-impl ast::AttrsOwner for LifetimeParam {}
-impl LifetimeParam {
-    pub fn lifetime_token(&self) -> Option<SyntaxToken> {
-        support::token(&self.syntax, T![lifetime])
-    }
-}
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct ConstParam {
-    pub(crate) syntax: SyntaxNode,
-}
-impl ast::AttrsOwner for ConstParam {}
-impl ast::NameOwner for ConstParam {}
-impl ast::TypeAscriptionOwner for ConstParam {}
-impl ConstParam {
-    pub fn const_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![const]) }
-    pub fn colon_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![:]) }
-    pub fn eq_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![=]) }
-    pub fn default_val(&self) -> Option<Expr> { support::child(&self.syntax) }
-}
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct TypeBound {
     pub(crate) syntax: SyntaxNode,
 }
@@ -1383,6 +1381,13 @@ pub enum ExternItem {
 impl ast::AttrsOwner for ExternItem {}
 impl ast::NameOwner for ExternItem {}
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum GenericParam {
+    LifetimeParam(LifetimeParam),
+    TypeParam(TypeParam),
+    ConstParam(ConstParam),
+}
+impl ast::AttrsOwner for GenericParam {}
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum Stmt {
     LetStmt(LetStmt),
     ExprStmt(ExprStmt),
@@ -1854,6 +1859,39 @@ impl AstNode for ExternItemList {
     }
     fn syntax(&self) -> &SyntaxNode { &self.syntax }
 }
+impl AstNode for LifetimeParam {
+    fn can_cast(kind: SyntaxKind) -> bool { kind == LIFETIME_PARAM }
+    fn cast(syntax: SyntaxNode) -> Option<Self> {
+        if Self::can_cast(syntax.kind()) {
+            Some(Self { syntax })
+        } else {
+            None
+        }
+    }
+    fn syntax(&self) -> &SyntaxNode { &self.syntax }
+}
+impl AstNode for TypeParam {
+    fn can_cast(kind: SyntaxKind) -> bool { kind == TYPE_PARAM }
+    fn cast(syntax: SyntaxNode) -> Option<Self> {
+        if Self::can_cast(syntax.kind()) {
+            Some(Self { syntax })
+        } else {
+            None
+        }
+    }
+    fn syntax(&self) -> &SyntaxNode { &self.syntax }
+}
+impl AstNode for ConstParam {
+    fn can_cast(kind: SyntaxKind) -> bool { kind == CONST_PARAM }
+    fn cast(syntax: SyntaxNode) -> Option<Self> {
+        if Self::can_cast(syntax.kind()) {
+            Some(Self { syntax })
+        } else {
+            None
+        }
+    }
+    fn syntax(&self) -> &SyntaxNode { &self.syntax }
+}
 impl AstNode for ParenType {
     fn can_cast(kind: SyntaxKind) -> bool { kind == PAREN_TYPE }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
@@ -2635,39 +2673,6 @@ impl AstNode for MacroStmts {
     }
     fn syntax(&self) -> &SyntaxNode { &self.syntax }
 }
-impl AstNode for TypeParam {
-    fn can_cast(kind: SyntaxKind) -> bool { kind == TYPE_PARAM }
-    fn cast(syntax: SyntaxNode) -> Option<Self> {
-        if Self::can_cast(syntax.kind()) {
-            Some(Self { syntax })
-        } else {
-            None
-        }
-    }
-    fn syntax(&self) -> &SyntaxNode { &self.syntax }
-}
-impl AstNode for LifetimeParam {
-    fn can_cast(kind: SyntaxKind) -> bool { kind == LIFETIME_PARAM }
-    fn cast(syntax: SyntaxNode) -> Option<Self> {
-        if Self::can_cast(syntax.kind()) {
-            Some(Self { syntax })
-        } else {
-            None
-        }
-    }
-    fn syntax(&self) -> &SyntaxNode { &self.syntax }
-}
-impl AstNode for ConstParam {
-    fn can_cast(kind: SyntaxKind) -> bool { kind == CONST_PARAM }
-    fn cast(syntax: SyntaxNode) -> Option<Self> {
-        if Self::can_cast(syntax.kind()) {
-            Some(Self { syntax })
-        } else {
-            None
-        }
-    }
-    fn syntax(&self) -> &SyntaxNode { &self.syntax }
-}
 impl AstNode for TypeBound {
     fn can_cast(kind: SyntaxKind) -> bool { kind == TYPE_BOUND }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
@@ -3325,6 +3330,39 @@ impl AstNode for ExternItem {
         }
     }
 }
+impl From<LifetimeParam> for GenericParam {
+    fn from(node: LifetimeParam) -> GenericParam { GenericParam::LifetimeParam(node) }
+}
+impl From<TypeParam> for GenericParam {
+    fn from(node: TypeParam) -> GenericParam { GenericParam::TypeParam(node) }
+}
+impl From<ConstParam> for GenericParam {
+    fn from(node: ConstParam) -> GenericParam { GenericParam::ConstParam(node) }
+}
+impl AstNode for GenericParam {
+    fn can_cast(kind: SyntaxKind) -> bool {
+        match kind {
+            LIFETIME_PARAM | TYPE_PARAM | CONST_PARAM => true,
+            _ => false,
+        }
+    }
+    fn cast(syntax: SyntaxNode) -> Option<Self> {
+        let res = match syntax.kind() {
+            LIFETIME_PARAM => GenericParam::LifetimeParam(LifetimeParam { syntax }),
+            TYPE_PARAM => GenericParam::TypeParam(TypeParam { syntax }),
+            CONST_PARAM => GenericParam::ConstParam(ConstParam { syntax }),
+            _ => return None,
+        };
+        Some(res)
+    }
+    fn syntax(&self) -> &SyntaxNode {
+        match self {
+            GenericParam::LifetimeParam(it) => &it.syntax,
+            GenericParam::TypeParam(it) => &it.syntax,
+            GenericParam::ConstParam(it) => &it.syntax,
+        }
+    }
+}
 impl From<LetStmt> for Stmt {
     fn from(node: LetStmt) -> Stmt { Stmt::LetStmt(node) }
 }
@@ -3449,6 +3487,11 @@ impl std::fmt::Display for ExternItem {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
+impl std::fmt::Display for GenericParam {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl std::fmt::Display for Stmt {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
@@ -3669,6 +3712,21 @@ impl std::fmt::Display for ExternItemList {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
+impl std::fmt::Display for LifetimeParam {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
+impl std::fmt::Display for TypeParam {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
+impl std::fmt::Display for ConstParam {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl std::fmt::Display for ParenType {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
@@ -4024,21 +4082,6 @@ impl std::fmt::Display for MacroStmts {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
-impl std::fmt::Display for TypeParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        std::fmt::Display::fmt(self.syntax(), f)
-    }
-}
-impl std::fmt::Display for LifetimeParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        std::fmt::Display::fmt(self.syntax(), f)
-    }
-}
-impl std::fmt::Display for ConstParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        std::fmt::Display::fmt(self.syntax(), f)
-    }
-}
 impl std::fmt::Display for TypeBound {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
diff --git a/crates/ra_syntax/src/ast/node_ext.rs b/crates/ra_syntax/src/ast/node_ext.rs
index 313f52226..d2ee9586d 100644
--- a/crates/ra_syntax/src/ast/node_ext.rs
+++ b/crates/ra_syntax/src/ast/node_ext.rs
@@ -473,6 +473,27 @@ impl ast::TokenTree {
     }
 }
 
+impl ast::GenericParamList {
+    pub fn lifetime_params(&self) -> impl Iterator<Item = ast::LifetimeParam> {
+        self.generic_params().filter_map(|param| match param {
+            ast::GenericParam::LifetimeParam(it) => Some(it),
+            ast::GenericParam::TypeParam(_) | ast::GenericParam::ConstParam(_) => None,
+        })
+    }
+    pub fn type_params(&self) -> impl Iterator<Item = ast::TypeParam> {
+        self.generic_params().filter_map(|param| match param {
+            ast::GenericParam::TypeParam(it) => Some(it),
+            ast::GenericParam::LifetimeParam(_) | ast::GenericParam::ConstParam(_) => None,
+        })
+    }
+    pub fn const_params(&self) -> impl Iterator<Item = ast::ConstParam> {
+        self.generic_params().filter_map(|param| match param {
+            ast::GenericParam::ConstParam(it) => Some(it),
+            ast::GenericParam::TypeParam(_) | ast::GenericParam::LifetimeParam(_) => None,
+        })
+    }
+}
+
 impl ast::DocCommentsOwner for ast::SourceFile {}
 impl ast::DocCommentsOwner for ast::Fn {}
 impl ast::DocCommentsOwner for ast::Struct {}
diff --git a/xtask/src/ast_src.rs b/xtask/src/ast_src.rs
index c7087a14e..114898e38 100644
--- a/xtask/src/ast_src.rs
+++ b/xtask/src/ast_src.rs
@@ -204,6 +204,7 @@ pub(crate) const KINDS_SRC: KindsSrc = KindsSrc {
         "LET_STMT",
         "EXPR_STMT",
         "GENERIC_PARAM_LIST",
+        "GENERIC_PARAM",
         "LIFETIME_PARAM",
         "TYPE_PARAM",
         "CONST_PARAM",
diff --git a/xtask/src/codegen/rust.ungram b/xtask/src/codegen/rust.ungram
index cdd3adf45..4025f7f96 100644
--- a/xtask/src/codegen/rust.ungram
+++ b/xtask/src/codegen/rust.ungram
@@ -154,6 +154,25 @@ ExternItemList =
 ExternItem =
   Fn | Static | MacroCall
 
+GenericParamList =
+  '<' (GenericParam (',' GenericParam)* ','?)? '>'
+
+GenericParam =
+  LifetimeParam
+| TypeParam
+| ConstParam
+
+TypeParam =
+  Attr* Name (':' TypeBoundList?)?
+  ('=' default_type:TypeRef)?
+
+ConstParam =
+  Attr* 'const' Name ':' ascribed_type:TypeRef
+  ('=' default_val:Expr)?
+
+LifetimeParam =
+  Attr* 'lifetime'
+
 ParenType =
   '(' TypeRef ')'
 
@@ -400,24 +419,6 @@ MacroStmts =
 Attr =
   '#' '!'? '[' Path ('=' input:AttrInput)? ']'
 
-GenericParamList =
-  '<'
-    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