Merge #11954

11954: Parse `for<'a>` closure syntax r=Veykril a=Veykril

Fixes https://github.com/rust-analyzer/rust-analyzer/issues/11716

Co-authored-by: Lukas Wirth <lukastw97@gmail.com>

crates/parser/src/grammar/expressions/atom.rs

@@ -71,16 +71,8 @@ pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMar
     let done = match p.current() {
         T!['('] => tuple_expr(p),
         T!['['] => array_expr(p),
-        T![|] => closure_expr(p),
-        T![static] | T![async] | T![move] if la == T![|] => closure_expr(p),
-        T![static] | T![async] if la == T![move] && p.nth(2) == T![|] => closure_expr(p),
-        T![static] if la == T![async] && p.nth(2) == T![|] => closure_expr(p),
-        T![static] if la == T![async] && p.nth(2) == T![move] && p.nth(3) == T![|] => {
-            closure_expr(p)
-        }
         T![if] => if_expr(p),
         T![let] => let_expr(p),
-
         T![_] => {
             // test destructuring_assignment_wildcard_pat
             // fn foo() {
@@ -91,12 +83,16 @@ pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMar
             p.bump(T![_]);
             m.complete(p, UNDERSCORE_EXPR)
         }
-
         T![loop] => loop_expr(p, None),
         T![box] => box_expr(p, None),
-        T![for] => for_expr(p, None),
         T![while] => while_expr(p, None),
         T![try] => try_block_expr(p, None),
+        T![match] => match_expr(p),
+        T![return] => return_expr(p),
+        T![yield] => yield_expr(p),
+        T![continue] => continue_expr(p),
+        T![break] => break_expr(p, r),
+
         LIFETIME_IDENT if la == T![:] => {
             let m = p.start();
             label(p);
@@ -121,30 +117,24 @@ pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMar
                 }
             }
         }
-        T![async] if la == T!['{'] || (la == T![move] && p.nth(2) == T!['{']) => {
+        // test effect_blocks
+        // fn f() { unsafe { } }
+        // fn f() { const { } }
+        // fn f() { async { } }
+        // fn f() { async move { } }
+        T![const] | T![unsafe] | T![async] if la == T!['{'] => {
+            let m = p.start();
+            p.bump_any();
+            stmt_list(p);
+            m.complete(p, BLOCK_EXPR)
+        }
+        T![async] if la == T![move] && p.nth(2) == T!['{'] => {
             let m = p.start();
             p.bump(T![async]);
             p.eat(T![move]);
             stmt_list(p);
             m.complete(p, BLOCK_EXPR)
         }
-        T![match] => match_expr(p),
-        // test unsafe_block
-        // fn f() { unsafe { } }
-        T![unsafe] if la == T!['{'] => {
-            let m = p.start();
-            p.bump(T![unsafe]);
-            stmt_list(p);
-            m.complete(p, BLOCK_EXPR)
-        }
-        // test const_block
-        // fn f() { const { } }
-        T![const] if la == T!['{'] => {
-            let m = p.start();
-            p.bump(T![const]);
-            stmt_list(p);
-            m.complete(p, BLOCK_EXPR)
-        }
         T!['{'] => {
             // test for_range_from
             // fn foo() {
@@ -156,10 +146,11 @@ pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMar
             stmt_list(p);
             m.complete(p, BLOCK_EXPR)
         }
-        T![return] => return_expr(p),
+
-        T![yield] => yield_expr(p),
+        T![static] | T![async] | T![move] | T![|] => closure_expr(p),
-        T![continue] => continue_expr(p),
+        T![for] if la == T![<] => closure_expr(p),
-        T![break] => break_expr(p, r),
+        T![for] => for_expr(p, None),
+
         _ => {
             p.err_recover("expected expression", EXPR_RECOVERY_SET);
             return None;
@@ -254,25 +245,30 @@ fn array_expr(p: &mut Parser) -> CompletedMarker {
 //     static move || {};
 //     static async || {};
 //     static async move || {};
+//     for<'a> || {};
+//     for<'a> move || {};
 // }
 fn closure_expr(p: &mut Parser) -> CompletedMarker {
-    assert!(
+    assert!(match p.current() {
-        p.at(T![|])
+        T![static] | T![async] | T![move] | T![|] => true,
-            || (p.at(T![move]) && p.nth(1) == T![|])
+        T![for] => p.nth(1) == T![<],
-            || (p.at(T![async]) && p.nth(1) == T![|])
+        _ => false,
-            || (p.at(T![async]) && p.nth(1) == T![move] && p.nth(2) == T![|])
+    });
-            || (p.at(T![static]) && p.nth(1) == T![|])
+
-            || (p.at(T![static]) && p.nth(1) == T![move] && p.nth(2) == T![|])
-            || (p.at(T![static]) && p.nth(1) == T![async] && p.nth(2) == T![|])
-            || (p.at(T![static])
-                && p.nth(1) == T![async]
-                && p.nth(2) == T![move]
-                && p.nth(3) == T![|])
-    );
     let m = p.start();
+
+    if p.at(T![for]) {
+        types::for_binder(p);
+    }
+
     p.eat(T![static]);
     p.eat(T![async]);
     p.eat(T![move]);
+
+    if !p.at(T![|]) {
+        p.error("expected `|`");
+        return m.complete(p, CLOSURE_EXPR);
+    }
     params::param_list_closure(p);
     if opt_ret_type(p) {
         // test lambda_ret_block

crates/parser/test_data/parser/err/0024_many_type_parens.rast

@@ -182,45 +182,44 @@ SOURCE_FILE
         WHITESPACE " "
         TUPLE_EXPR
           L_PAREN "("
-          FOR_EXPR
+          CLOSURE_EXPR
             FOR_KW "for"
-            PATH_PAT
+            GENERIC_PARAM_LIST
-              PATH
+              L_ANGLE "<"
-                PATH_SEGMENT
+              LIFETIME_PARAM
-                  L_ANGLE "<"
+                LIFETIME
-                  ERROR
+                  LIFETIME_IDENT "'a"
-                    LIFETIME_IDENT "'a"
+              R_ANGLE ">"
-                  R_ANGLE ">"
+          WHITESPACE " "
-            WHITESPACE " "
+          BIN_EXPR
             BIN_EXPR
               BIN_EXPR
                 BIN_EXPR
-                  BIN_EXPR
-                    PATH_EXPR
-                      PATH
-                        PATH_SEGMENT
-                          NAME_REF
-                            IDENT "Trait"
-                    L_ANGLE "<"
-                    ERROR
-                      LIFETIME_IDENT "'a"
-                  R_ANGLE ">"
-                  ERROR
-                    R_PAREN ")"
-                WHITESPACE " "
-                PLUS "+"
-                WHITESPACE " "
-                PAREN_EXPR
-                  L_PAREN "("
                   PATH_EXPR
                     PATH
                       PATH_SEGMENT
                         NAME_REF
-                          IDENT "Copy"
+                          IDENT "Trait"
+                  L_ANGLE "<"
+                  ERROR
+                    LIFETIME_IDENT "'a"
+                R_ANGLE ">"
+                ERROR
                   R_PAREN ")"
-              R_ANGLE ">"
+              WHITESPACE " "
-              ERROR
+              PLUS "+"
-                SEMICOLON ";"
+              WHITESPACE " "
+              PAREN_EXPR
+                L_PAREN "("
+                PATH_EXPR
+                  PATH
+                    PATH_SEGMENT
+                      NAME_REF
+                        IDENT "Copy"
+                R_PAREN ")"
+            R_ANGLE ">"
+            ERROR
+              SEMICOLON ";"
           WHITESPACE "\n    "
           LET_EXPR
             LET_KW "let"
@@ -240,49 +239,48 @@ SOURCE_FILE
               L_ANGLE "<"
               TUPLE_EXPR
                 L_PAREN "("
-                FOR_EXPR
+                CLOSURE_EXPR
                   FOR_KW "for"
-                  PATH_PAT
+                  GENERIC_PARAM_LIST
-                    PATH
+                    L_ANGLE "<"
-                      PATH_SEGMENT
+                    LIFETIME_PARAM
-                        L_ANGLE "<"
+                      LIFETIME
-                        ERROR
+                        LIFETIME_IDENT "'a"
-                          LIFETIME_IDENT "'a"
+                    R_ANGLE ">"
-                        R_ANGLE ">"
+                WHITESPACE " "
-                  WHITESPACE " "
+                BIN_EXPR
                   BIN_EXPR
                     BIN_EXPR
                       BIN_EXPR
-                        BIN_EXPR
-                          PATH_EXPR
-                            PATH
-                              PATH_SEGMENT
-                                NAME_REF
-                                  IDENT "Trait"
-                          L_ANGLE "<"
-                          ERROR
-                            LIFETIME_IDENT "'a"
-                        R_ANGLE ">"
-                        ERROR
-                          R_PAREN ")"
-                      WHITESPACE " "
-                      PLUS "+"
-                      WHITESPACE " "
-                      PAREN_EXPR
-                        L_PAREN "("
                         PATH_EXPR
                           PATH
                             PATH_SEGMENT
                               NAME_REF
-                                IDENT "Copy"
+                                IDENT "Trait"
+                        L_ANGLE "<"
+                        ERROR
+                          LIFETIME_IDENT "'a"
+                      R_ANGLE ">"
+                      ERROR
                         R_PAREN ")"
                     WHITESPACE " "
                     PLUS "+"
                     WHITESPACE " "
                     PAREN_EXPR
                       L_PAREN "("
-                      ERROR
+                      PATH_EXPR
-                        QUESTION "?"
+                        PATH
+                          PATH_SEGMENT
+                            NAME_REF
+                              IDENT "Copy"
+                      R_PAREN ")"
+                  WHITESPACE " "
+                  PLUS "+"
+                  WHITESPACE " "
+                  PAREN_EXPR
+                    L_PAREN "("
+                    ERROR
+                      QUESTION "?"
                 PATH_EXPR
                   PATH
                     PATH_SEGMENT
@@ -307,23 +305,21 @@ error 141: expected SEMICOLON
 error 146: expected SEMICOLON
 error 146: expected expression
 error 148: expected expression
-error 155: expected type
+error 158: expected `|`
-error 158: expected IN_KW
+error 158: expected COMMA
 error 165: expected expression
 error 168: expected expression
 error 179: expected expression
-error 180: expected a block
 error 180: expected COMMA
 error 190: expected EQ
 error 190: expected expression
 error 191: expected COMMA
-error 201: expected type
+error 204: expected `|`
-error 204: expected IN_KW
+error 204: expected COMMA
 error 211: expected expression
 error 214: expected expression
 error 228: expected expression
 error 229: expected R_PAREN
-error 229: expected a block
 error 229: expected COMMA
 error 236: expected expression
 error 237: expected COMMA

crates/parser/test_data/parser/inline/ok/0106_lambda_expr.rast

@@ -199,6 +199,48 @@ SOURCE_FILE
                 L_CURLY "{"
                 R_CURLY "}"
           SEMICOLON ";"
+        WHITESPACE "\n    "
+        EXPR_STMT
+          CLOSURE_EXPR
+            FOR_KW "for"
+            GENERIC_PARAM_LIST
+              L_ANGLE "<"
+              LIFETIME_PARAM
+                LIFETIME
+                  LIFETIME_IDENT "'a"
+              R_ANGLE ">"
+            WHITESPACE " "
+            PARAM_LIST
+              PIPE "|"
+              PIPE "|"
+            WHITESPACE " "
+            BLOCK_EXPR
+              STMT_LIST
+                L_CURLY "{"
+                R_CURLY "}"
+          SEMICOLON ";"
+        WHITESPACE "\n    "
+        EXPR_STMT
+          CLOSURE_EXPR
+            FOR_KW "for"
+            GENERIC_PARAM_LIST
+              L_ANGLE "<"
+              LIFETIME_PARAM
+                LIFETIME
+                  LIFETIME_IDENT "'a"
+              R_ANGLE ">"
+            WHITESPACE " "
+            MOVE_KW "move"
+            WHITESPACE " "
+            PARAM_LIST
+              PIPE "|"
+              PIPE "|"
+            WHITESPACE " "
+            BLOCK_EXPR
+              STMT_LIST
+                L_CURLY "{"
+                R_CURLY "}"
+          SEMICOLON ";"
         WHITESPACE "\n"
         R_CURLY "}"
   WHITESPACE "\n"

crates/parser/test_data/parser/inline/ok/0106_lambda_expr.rs

@@ -10,4 +10,6 @@ fn foo() {
     static move || {};
     static async || {};
     static async move || {};
+    for<'a> || {};
+    for<'a> move || {};
 }

crates/parser/test_data/parser/inline/ok/0157_const_block.rast

@@ -1,24 +0,0 @@
-SOURCE_FILE
-  FN
-    FN_KW "fn"
-    WHITESPACE " "
-    NAME
-      IDENT "f"
-    PARAM_LIST
-      L_PAREN "("
-      R_PAREN ")"
-    WHITESPACE " "
-    BLOCK_EXPR
-      STMT_LIST
-        L_CURLY "{"
-        WHITESPACE " "
-        BLOCK_EXPR
-          CONST_KW "const"
-          WHITESPACE " "
-          STMT_LIST
-            L_CURLY "{"
-            WHITESPACE " "
-            R_CURLY "}"
-        WHITESPACE " "
-        R_CURLY "}"
-  WHITESPACE "\n"

crates/parser/test_data/parser/inline/ok/0157_const_block.rs

@@ -1 +0,0 @@
-fn f() { const { } }

crates/parser/test_data/parser/inline/ok/0162_unsafe_block.rast

@@ -1,24 +0,0 @@
-SOURCE_FILE
-  FN
-    FN_KW "fn"
-    WHITESPACE " "
-    NAME
-      IDENT "f"
-    PARAM_LIST
-      L_PAREN "("
-      R_PAREN ")"
-    WHITESPACE " "
-    BLOCK_EXPR
-      STMT_LIST
-        L_CURLY "{"
-        WHITESPACE " "
-        BLOCK_EXPR
-          UNSAFE_KW "unsafe"
-          WHITESPACE " "
-          STMT_LIST
-            L_CURLY "{"
-            WHITESPACE " "
-            R_CURLY "}"
-        WHITESPACE " "
-        R_CURLY "}"
-  WHITESPACE "\n"

crates/parser/test_data/parser/inline/ok/0162_unsafe_block.rs

@@ -1 +0,0 @@
-fn f() { unsafe { } }

crates/parser/test_data/parser/inline/ok/0199_effect_blocks.rast

@@ -0,0 +1,95 @@
+SOURCE_FILE
+  FN
+    FN_KW "fn"
+    WHITESPACE " "
+    NAME
+      IDENT "f"
+    PARAM_LIST
+      L_PAREN "("
+      R_PAREN ")"
+    WHITESPACE " "
+    BLOCK_EXPR
+      STMT_LIST
+        L_CURLY "{"
+        WHITESPACE " "
+        BLOCK_EXPR
+          UNSAFE_KW "unsafe"
+          WHITESPACE " "
+          STMT_LIST
+            L_CURLY "{"
+            WHITESPACE " "
+            R_CURLY "}"
+        WHITESPACE " "
+        R_CURLY "}"
+  WHITESPACE "\n"
+  FN
+    FN_KW "fn"
+    WHITESPACE " "
+    NAME
+      IDENT "f"
+    PARAM_LIST
+      L_PAREN "("
+      R_PAREN ")"
+    WHITESPACE " "
+    BLOCK_EXPR
+      STMT_LIST
+        L_CURLY "{"
+        WHITESPACE " "
+        BLOCK_EXPR
+          CONST_KW "const"
+          WHITESPACE " "
+          STMT_LIST
+            L_CURLY "{"
+            WHITESPACE " "
+            R_CURLY "}"
+        WHITESPACE " "
+        R_CURLY "}"
+  WHITESPACE "\n"
+  FN
+    FN_KW "fn"
+    WHITESPACE " "
+    NAME
+      IDENT "f"
+    PARAM_LIST
+      L_PAREN "("
+      R_PAREN ")"
+    WHITESPACE " "
+    BLOCK_EXPR
+      STMT_LIST
+        L_CURLY "{"
+        WHITESPACE " "
+        BLOCK_EXPR
+          ASYNC_KW "async"
+          WHITESPACE " "
+          STMT_LIST
+            L_CURLY "{"
+            WHITESPACE " "
+            R_CURLY "}"
+        WHITESPACE " "
+        R_CURLY "}"
+  WHITESPACE "\n"
+  FN
+    FN_KW "fn"
+    WHITESPACE " "
+    NAME
+      IDENT "f"
+    PARAM_LIST
+      L_PAREN "("
+      R_PAREN ")"
+    WHITESPACE " "
+    BLOCK_EXPR
+      STMT_LIST
+        L_CURLY "{"
+        WHITESPACE " "
+        BLOCK_EXPR
+          ASYNC_KW "async"
+          WHITESPACE " "
+          MOVE_KW "move"
+          WHITESPACE " "
+          STMT_LIST
+            L_CURLY "{"
+            WHITESPACE " "
+            R_CURLY "}"
+        WHITESPACE " "
+        R_CURLY "}"
+  WHITESPACE "\n"

crates/parser/test_data/parser/inline/ok/0199_effect_blocks.rs

@@ -0,0 +1,4 @@
+fn f() { unsafe { } }
+fn f() { const { } }
+fn f() { async { } }
+fn f() { async move { } }

crates/syntax/rust.ungram

@@ -449,7 +449,7 @@ FieldExpr =
   Attr* Expr '.' NameRef
 
 ClosureExpr =
-  Attr* 'static'? 'async'? 'move'?  ParamList RetType?
+  Attr* ('for' GenericParamList)? 'static'? 'async'? 'move'?  ParamList RetType?
   body:Expr
 
 IfExpr =

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

@@ -837,6 +837,8 @@ pub struct ClosureExpr {
 }
 impl ast::HasAttrs for ClosureExpr {}
 impl ClosureExpr {
+    pub fn for_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![for]) }
+    pub fn generic_param_list(&self) -> Option<GenericParamList> { support::child(&self.syntax) }
     pub fn static_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![static]) }
     pub fn async_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![async]) }
     pub fn move_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![move]) }