Item is a Stmt

crates/ra_assists/src/handlers/change_return_type_to_result.rs

@@ -74,6 +74,7 @@ impl TailReturnCollector {
             let expr = match &stmt {
                 ast::Stmt::ExprStmt(stmt) => stmt.expr(),
                 ast::Stmt::LetStmt(stmt) => stmt.initializer(),
+                ast::Stmt::Item(_) => continue,
             };
             if let Some(expr) = &expr {
                 self.handle_exprs(expr, collect_break);
@@ -94,6 +95,7 @@ impl TailReturnCollector {
                         let expr_stmt = match &expr_stmt {
                             ast::Stmt::ExprStmt(stmt) => stmt.expr(),
                             ast::Stmt::LetStmt(stmt) => stmt.initializer(),
+                            ast::Stmt::Item(_) => None,
                         };
                         if let Some(expr) = &expr_stmt {
                             self.handle_exprs(expr, collect_break);

crates/ra_hir_def/src/body/lower.rs

@@ -10,7 +10,7 @@ use hir_expand::{
 use ra_arena::Arena;
 use ra_syntax::{
     ast::{
-        self, ArgListOwner, ArrayExprKind, LiteralKind, LoopBodyOwner, ModuleItemOwner, NameOwner,
+        self, ArgListOwner, ArrayExprKind, LiteralKind, LoopBodyOwner, NameOwner,
         SlicePatComponents,
     },
     AstNode, AstPtr,
@@ -601,14 +601,20 @@ impl ExprCollector<'_> {
         self.collect_block_items(&block);
         let statements = block
             .statements()
-            .map(|s| match s {
-                ast::Stmt::LetStmt(stmt) => {
-                    let pat = self.collect_pat_opt(stmt.pat());
-                    let type_ref = stmt.ty().map(|it| TypeRef::from_ast(&self.ctx(), it));
-                    let initializer = stmt.initializer().map(|e| self.collect_expr(e));
-                    Statement::Let { pat, type_ref, initializer }
-                }
-                ast::Stmt::ExprStmt(stmt) => Statement::Expr(self.collect_expr_opt(stmt.expr())),
+            .filter_map(|s| {
+                let stmt = match s {
+                    ast::Stmt::LetStmt(stmt) => {
+                        let pat = self.collect_pat_opt(stmt.pat());
+                        let type_ref = stmt.ty().map(|it| TypeRef::from_ast(&self.ctx(), it));
+                        let initializer = stmt.initializer().map(|e| self.collect_expr(e));
+                        Statement::Let { pat, type_ref, initializer }
+                    }
+                    ast::Stmt::ExprStmt(stmt) => {
+                        Statement::Expr(self.collect_expr_opt(stmt.expr()))
+                    }
+                    ast::Stmt::Item(_) => return None,
+                };
+                Some(stmt)
             })
             .collect();
         let tail = block.expr().map(|e| self.collect_expr(e));
@@ -620,7 +626,11 @@ impl ExprCollector<'_> {
         let container = ContainerId::DefWithBodyId(self.def);
 
         let items = block
-            .items()
+            .statements()
+            .filter_map(|stmt| match stmt {
+                ast::Stmt::Item(it) => Some(it),
+                ast::Stmt::LetStmt(_) | ast::Stmt::ExprStmt(_) => None,
+            })
             .filter_map(|item| {
                 let (def, name): (ModuleDefId, Option<ast::Name>) = match item {
                     ast::Item::Fn(def) => {

crates/ra_syntax/src/ast/generated.rs

@@ -17,14 +17,17 @@ impl AstNode for Stmt {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
             LET_STMT | EXPR_STMT => true,
-            _ => false,
+            _ => Item::can_cast(kind),
         }
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
             LET_STMT => Stmt::LetStmt(LetStmt { syntax }),
             EXPR_STMT => Stmt::ExprStmt(ExprStmt { syntax }),
-            _ => return None,
+            _ => {
+                let item = Item::cast(syntax)?;
+                Stmt::Item(item)
+            }
         };
         Some(res)
     }
@@ -32,6 +35,7 @@ impl AstNode for Stmt {
         match self {
             Stmt::LetStmt(it) => &it.syntax,
             Stmt::ExprStmt(it) => &it.syntax,
+            Stmt::Item(it) => it.syntax(),
         }
     }
 }

crates/ra_syntax/src/ast/generated/nodes.rs

@@ -348,7 +348,6 @@ pub struct BlockExpr {
     pub(crate) syntax: SyntaxNode,
 }
 impl ast::AttrsOwner for BlockExpr {}
-impl ast::ModuleItemOwner for BlockExpr {}
 impl BlockExpr {
     pub fn label(&self) -> Option<Label> { support::child(&self.syntax) }
     pub fn l_curly_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T!['{']) }
@@ -1395,8 +1394,8 @@ impl ast::AttrsOwner for GenericParam {}
 pub enum Stmt {
     LetStmt(LetStmt),
     ExprStmt(ExprStmt),
+    Item(Item),
 }
-impl ast::AttrsOwner for Stmt {}
 impl AstNode for SourceFile {
     fn can_cast(kind: SyntaxKind) -> bool { kind == SOURCE_FILE }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
@@ -3380,6 +3379,9 @@ impl From<LetStmt> for Stmt {
 impl From<ExprStmt> for Stmt {
     fn from(node: ExprStmt) -> Stmt { Stmt::ExprStmt(node) }
 }
+impl From<Item> for Stmt {
+    fn from(node: Item) -> Stmt { Stmt::Item(node) }
+}
 impl std::fmt::Display for Item {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)

xtask/src/codegen/gen_syntax.rs

@@ -694,6 +694,9 @@ fn extract_struct_trait(node: &mut AstNodeSrc, trait_name: &str, methods: &[&str
 
 fn extract_enum_traits(ast: &mut AstSrc) {
     for enm in &mut ast.enums {
+        if enm.name == "Stmt" {
+            continue;
+        }
         let nodes = &ast.nodes;
         let mut variant_traits = enm
             .variants

xtask/src/codegen/rust.ungram

@@ -197,6 +197,7 @@ Attr =
 Stmt =
   LetStmt
 | ExprStmt
+| Item
 
 LetStmt =
   Attr* 'let' Pat (':' Type)?
@@ -316,7 +317,6 @@ Label =
 BlockExpr =
   Attr* Label
   '{'
-    Item*
     statements:Stmt*
     Expr?
   '}'