Merge #1676

1676: Fix for<'lifetime> for types specified by path r=matklad a=eupn

Fixes #1467.

Co-authored-by: Evgenii P <eupn@protonmail.com>

crates/ra_parser/src/grammar/expressions.rs

@@ -554,7 +554,7 @@ fn arg_list(p: &mut Parser) {
 //     let _ = format!();
 // }
 fn path_expr(p: &mut Parser, r: Restrictions) -> (CompletedMarker, BlockLike) {
-    assert!(paths::is_path_start(p) || p.at(T![<]));
+    assert!(paths::is_path_start(p));
     let m = p.start();
     paths::expr_path(p);
     match p.current() {

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

@@ -62,7 +62,7 @@ pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMar
     if let Some(m) = literal(p) {
         return Some((m, BlockLike::NotBlock));
     }
-    if paths::is_path_start(p) || p.at(T![<]) {
+    if paths::is_path_start(p) {
         return Some(path_expr(p, r));
     }
     let la = p.nth(1);

crates/ra_parser/src/grammar/items.rs

@@ -49,7 +49,7 @@ pub(super) fn item_or_macro(p: &mut Parser, stop_on_r_curly: bool, flavor: ItemF
         }
         Err(m) => m,
     };
-    if paths::is_path_start(p) {
+    if paths::is_use_path_start(p) {
         match macro_call(p) {
             BlockLike::Block => (),
             BlockLike::NotBlock => {
@@ -378,7 +378,7 @@ pub(crate) fn mod_item_list(p: &mut Parser) {
 }
 
 fn macro_call(p: &mut Parser) -> BlockLike {
-    assert!(paths::is_path_start(p));
+    assert!(paths::is_use_path_start(p));
     paths::use_path(p);
     macro_call_after_excl(p)
 }

crates/ra_parser/src/grammar/items/use_item.rs

@@ -65,7 +65,7 @@ fn use_tree(p: &mut Parser) {
         // use crate::Item;
         // use self::some::Struct;
         // use crate_name::some_item;
-        _ if paths::is_path_start(p) => {
+        _ if paths::is_use_path_start(p) => {
             paths::use_path(p);
             match p.current() {
                 T![as] => {

crates/ra_parser/src/grammar/paths.rs

@@ -4,6 +4,10 @@ pub(super) const PATH_FIRST: TokenSet =
     token_set![IDENT, SELF_KW, SUPER_KW, CRATE_KW, COLONCOLON, L_ANGLE];
 
 pub(super) fn is_path_start(p: &Parser) -> bool {
+    is_use_path_start(p) || p.at(T![<])
+}
+
+pub(super) fn is_use_path_start(p: &Parser) -> bool {
     match p.current() {
         IDENT | T![self] | T![super] | T![crate] | T![::] => true,
         _ => false,
@@ -58,7 +62,7 @@ fn path_segment(p: &mut Parser, mode: Mode, first: bool) {
     if first && p.eat(T![<]) {
         types::type_(p);
         if p.eat(T![as]) {
-            if is_path_start(p) {
+            if is_use_path_start(p) {
                 types::path_type(p);
             } else {
                 p.error("expected a trait");

crates/ra_parser/src/grammar/patterns.rs

@@ -65,7 +65,7 @@ fn atom_pat(p: &mut Parser, recovery_set: TokenSet) -> Option<CompletedMarker> {
     {
         return Some(bind_pat(p, true));
     }
-    if paths::is_path_start(p) {
+    if paths::is_use_path_start(p) {
         return Some(path_pat(p));
     }
 
@@ -118,7 +118,7 @@ fn literal_pat(p: &mut Parser) -> CompletedMarker {
 //     let Bar(..) = ();
 // }
 fn path_pat(p: &mut Parser) -> CompletedMarker {
-    assert!(paths::is_path_start(p));
+    assert!(paths::is_use_path_start(p));
     let m = p.start();
     paths::expr_path(p);
     let kind = match p.current() {

crates/ra_parser/src/grammar/type_params.rs

@@ -101,7 +101,7 @@ fn type_bound(p: &mut Parser) -> bool {
     match p.current() {
         LIFETIME => p.bump(),
         T![for] => types::for_type(p),
-        _ if paths::is_path_start(p) => types::path_type_(p, false),
+        _ if paths::is_use_path_start(p) => types::path_type_(p, false),
         _ => {
             m.abandon(p);
             return false;

crates/ra_parser/src/grammar/types.rs

@@ -29,7 +29,7 @@ fn type_with_bounds_cond(p: &mut Parser, allow_bounds: bool) {
         T![dyn ] => dyn_trait_type(p),
         // Some path types are not allowed to have bounds (no plus)
         T![<] => path_type_(p, allow_bounds),
-        _ if paths::is_path_start(p) => path_or_macro_type_(p, allow_bounds),
+        _ if paths::is_use_path_start(p) => path_or_macro_type_(p, allow_bounds),
         _ => {
             p.err_recover("expected type", TYPE_RECOVERY_SET);
         }
@@ -205,6 +205,7 @@ pub(super) fn for_binder(p: &mut Parser) {
 // type A = for<'a> fn() -> ();
 // fn foo<T>(_t: &T) where for<'a> &'a T: Iterator {}
 // fn bar<T>(_t: &T) where for<'a> &'a mut T: Iterator {}
+// fn baz<T>(_t: &T) where for<'a> <&'a T as Baz>::Foo: Iterator {}
 pub(super) fn for_type(p: &mut Parser) {
     assert!(p.at(T![for]));
     let m = p.start();
@@ -251,7 +252,7 @@ pub(super) fn path_type(p: &mut Parser) {
 // type A = foo!();
 // type B = crate::foo!();
 fn path_or_macro_type_(p: &mut Parser, allow_bounds: bool) {
-    assert!(paths::is_path_start(p) || p.at(T![<]));
+    assert!(paths::is_path_start(p));
     let m = p.start();
     paths::type_path(p);
 
@@ -270,7 +271,7 @@ fn path_or_macro_type_(p: &mut Parser, allow_bounds: bool) {
 }
 
 pub(super) fn path_type_(p: &mut Parser, allow_bounds: bool) {
-    assert!(paths::is_path_start(p) || p.at(T![<]));
+    assert!(paths::is_path_start(p));
     let m = p.start();
     paths::type_path(p);
 

crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs

@@ -1,3 +1,4 @@
 type A = for<'a> fn() -> ();
 fn foo<T>(_t: &T) where for<'a> &'a T: Iterator {}
 fn bar<T>(_t: &T) where for<'a> &'a mut T: Iterator {}
+fn baz<T>(_t: &T) where for<'a> <&'a T as Baz>::Foo: Iterator {}

crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.txt

@@ -1,4 +1,4 @@
-SOURCE_FILE@[0; 135)
+SOURCE_FILE@[0; 200)
   TYPE_ALIAS_DEF@[0; 28)
     TYPE_KW@[0; 4) "type"
     WHITESPACE@[4; 5) " "
@@ -157,3 +157,84 @@ SOURCE_FILE@[0; 135)
       L_CURLY@[132; 133) "{"
       R_CURLY@[133; 134) "}"
   WHITESPACE@[134; 135) "\n"
+  FN_DEF@[135; 199)
+    FN_KW@[135; 137) "fn"
+    WHITESPACE@[137; 138) " "
+    NAME@[138; 141)
+      IDENT@[138; 141) "baz"
+    TYPE_PARAM_LIST@[141; 144)
+      L_ANGLE@[141; 142) "<"
+      TYPE_PARAM@[142; 143)
+        NAME@[142; 143)
+          IDENT@[142; 143) "T"
+      R_ANGLE@[143; 144) ">"
+    PARAM_LIST@[144; 152)
+      L_PAREN@[144; 145) "("
+      PARAM@[145; 151)
+        BIND_PAT@[145; 147)
+          NAME@[145; 147)
+            IDENT@[145; 147) "_t"
+        COLON@[147; 148) ":"
+        WHITESPACE@[148; 149) " "
+        REFERENCE_TYPE@[149; 151)
+          AMP@[149; 150) "&"
+          PATH_TYPE@[150; 151)
+            PATH@[150; 151)
+              PATH_SEGMENT@[150; 151)
+                NAME_REF@[150; 151)
+                  IDENT@[150; 151) "T"
+      R_PAREN@[151; 152) ")"
+    WHITESPACE@[152; 153) " "
+    WHERE_CLAUSE@[153; 196)
+      WHERE_KW@[153; 158) "where"
+      WHITESPACE@[158; 159) " "
+      WHERE_PRED@[159; 196)
+        FOR_TYPE@[159; 186)
+          FOR_KW@[159; 162) "for"
+          TYPE_PARAM_LIST@[162; 166)
+            L_ANGLE@[162; 163) "<"
+            LIFETIME_PARAM@[163; 165)
+              LIFETIME@[163; 165) "\'a"
+            R_ANGLE@[165; 166) ">"
+          WHITESPACE@[166; 167) " "
+          PATH_TYPE@[167; 186)
+            PATH@[167; 186)
+              PATH@[167; 181)
+                PATH_SEGMENT@[167; 181)
+                  L_ANGLE@[167; 168) "<"
+                  REFERENCE_TYPE@[168; 173)
+                    AMP@[168; 169) "&"
+                    LIFETIME@[169; 171) "\'a"
+                    WHITESPACE@[171; 172) " "
+                    PATH_TYPE@[172; 173)
+                      PATH@[172; 173)
+                        PATH_SEGMENT@[172; 173)
+                          NAME_REF@[172; 173)
+                            IDENT@[172; 173) "T"
+                  WHITESPACE@[173; 174) " "
+                  AS_KW@[174; 176) "as"
+                  WHITESPACE@[176; 177) " "
+                  PATH_TYPE@[177; 180)
+                    PATH@[177; 180)
+                      PATH_SEGMENT@[177; 180)
+                        NAME_REF@[177; 180)
+                          IDENT@[177; 180) "Baz"
+                  R_ANGLE@[180; 181) ">"
+              COLONCOLON@[181; 183) "::"
+              PATH_SEGMENT@[183; 186)
+                NAME_REF@[183; 186)
+                  IDENT@[183; 186) "Foo"
+        COLON@[186; 187) ":"
+        WHITESPACE@[187; 188) " "
+        TYPE_BOUND_LIST@[188; 196)
+          TYPE_BOUND@[188; 196)
+            PATH_TYPE@[188; 196)
+              PATH@[188; 196)
+                PATH_SEGMENT@[188; 196)
+                  NAME_REF@[188; 196)
+                    IDENT@[188; 196) "Iterator"
+    WHITESPACE@[196; 197) " "
+    BLOCK@[197; 199)
+      L_CURLY@[197; 198) "{"
+      R_CURLY@[198; 199) "}"
+  WHITESPACE@[199; 200) "\n"