Add new TYPE_BOUND_LIST and TYPE_BOUND syntax kinds

These are now used when parsing type bounds. In addition parsing paths inside a
bound now does not recursively parse paths, rather they are treated as separate
bounds, separated by +.

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

@@ -2,6 +2,7 @@ use super::*;
 
 // test trait_item
 // trait T<U>: Hash + Clone where U: Copy {}
+// trait X<U: Debug + Display>: Hash + Clone where U: Copy {}
 pub(super) fn trait_def(p: &mut Parser) {
     assert!(p.at(TRAIT_KW));
     p.bump();

crates/ra_parser/src/grammar/type_params.rs

@@ -80,22 +80,29 @@ fn lifetime_bounds(p: &mut Parser) {
 }
 
 pub(super) fn bounds_without_colon(p: &mut Parser) {
+    let outer = p.start();
     loop {
+        let inner = p.start();
         let has_paren = p.eat(L_PAREN);
         p.eat(QUESTION);
         match p.current() {
             LIFETIME => p.bump(),
             FOR_KW => types::for_type(p),
-            _ if paths::is_path_start(p) => types::path_type(p),
-            _ => break,
+            _ if paths::is_path_start(p) => types::path_type_(p, false),
+            _ => {
+                inner.abandon(p);
+                break;
+            }
         }
         if has_paren {
             p.expect(R_PAREN);
         }
+        inner.complete(p, TYPE_BOUND);
         if !p.eat(PLUS) {
             break;
         }
     }
+    outer.complete(p, TYPE_BOUND_LIST);
 }
 
 // test where_clause

crates/ra_parser/src/syntax_kind/generated.rs

@@ -228,6 +228,8 @@ pub enum SyntaxKind {
     PARAM,
     SELF_PARAM,
     ARG_LIST,
+    TYPE_BOUND,
+    TYPE_BOUND_LIST,
 }
 use self::SyntaxKind::*;
 
@@ -567,6 +569,8 @@ impl SyntaxKind {
             PARAM => &SyntaxInfo { name: "PARAM" },
             SELF_PARAM => &SyntaxInfo { name: "SELF_PARAM" },
             ARG_LIST => &SyntaxInfo { name: "ARG_LIST" },
+            TYPE_BOUND => &SyntaxInfo { name: "TYPE_BOUND" },
+            TYPE_BOUND_LIST => &SyntaxInfo { name: "TYPE_BOUND_LIST" },
             TOMBSTONE => &SyntaxInfo { name: "TOMBSTONE" },
             EOF => &SyntaxInfo { name: "EOF" },
         }