Where clauses

4 files changed, 50 insertions, 15 deletions

diff --git a/src/grammar.ron b/src/grammar.ron
index df1dfe050..0443dd798 100644
--- a/src/grammar.ron
+++ b/src/grammar.ron
@@ -192,6 +192,7 @@ Grammar(
         "ALIAS",
         "VISIBILITY",
         "WHERE_CLAUSE",
+        "WHERE_PRED",
         "ABI",
         "NAME",
         "NAME_REF",
diff --git a/src/grammar/type_params.rs b/src/grammar/type_params.rs
index 1227482ad..0a3e8fd07 100644
--- a/src/grammar/type_params.rs
+++ b/src/grammar/type_params.rs
@@ -24,13 +24,8 @@ pub(super) fn type_param_list(p: &mut Parser) {
         assert!(p.at(LIFETIME));
         let m = p.start();
         p.bump();
-        if p.eat(COLON) {
-            while p.at(LIFETIME) {
-                p.bump();
-                if !p.eat(PLUS) {
-                    break;
-                }
-            }
+        if p.at(COLON) {
+            lifetime_bounds(p);
         }
         m.complete(p, LIFETIME_PARAM);
     }
@@ -60,6 +55,17 @@ pub(super) fn bounds(p: &mut Parser) {
     bounds_without_colon(p);
 }
 
+fn lifetime_bounds(p: &mut Parser) {
+    assert!(p.at(COLON));
+    p.bump();
+    while p.at(LIFETIME) {
+        p.bump();
+        if !p.eat(PLUS) {
+            break;
+        }
+    }
+}
+
 pub(super) fn bounds_without_colon(p: &mut Parser) {
     loop {
         let has_paren = p.eat(L_PAREN);
@@ -83,13 +89,39 @@ pub(super) fn bounds_without_colon(p: &mut Parser) {
     }
 }
 
+// test where_clause
+// fn foo()
+// where
+//    'a: 'b + 'c,
+//    T: Clone + Copy + 'static,
+//    Iterator::Item: 'a,
+// {}
 pub(super) fn where_clause(p: &mut Parser) {
-    if p.at(WHERE_KW) {
-        let m = p.start();
-        p.bump();
-        p.expect(IDENT);
-        p.expect(COLON);
-        p.expect(IDENT);
-        m.complete(p, WHERE_CLAUSE);
+    if !p.at(WHERE_KW) {
+        return;
+    }
+    let m = p.start();
+    p.bump();
+    loop {
+        if !(paths::is_path_start(p) || p.current() == LIFETIME) {
+            break
+        }
+        where_predicate(p);
+        if p.current() != L_CURLY && p.current() != SEMI {
+            p.expect(COMMA);
+        }
+    }
+    m.complete(p, WHERE_CLAUSE);
+}
+
+fn where_predicate(p: &mut Parser) {
+    let m = p.start();
+    if p.at(LIFETIME) {
+        p.eat(LIFETIME);
+        lifetime_bounds(p)
+    } else {
+        types::path_type(p);
+        bounds(p);
     }
+    m.complete(p, WHERE_PRED);
 }
diff --git a/src/grammar/types.rs b/src/grammar/types.rs
index c8ced3d28..0d8c6bfba 100644
--- a/src/grammar/types.rs
+++ b/src/grammar/types.rs
@@ -199,7 +199,7 @@ fn impl_trait_type(p: &mut Parser) {
 // type B = ::Foo;
 // type C = self::Foo;
 // type D = super::Foo;
-fn path_type(p: &mut Parser) {
+pub(super) fn path_type(p: &mut Parser) {
     assert!(paths::is_path_start(p));
     let m = p.start();
     paths::type_path(p);
diff --git a/src/syntax_kinds/generated.rs b/src/syntax_kinds/generated.rs
index a74acf6eb..9a9c1f223 100644
--- a/src/syntax_kinds/generated.rs
+++ b/src/syntax_kinds/generated.rs
@@ -175,6 +175,7 @@ pub enum SyntaxKind {
     ALIAS,
     VISIBILITY,
     WHERE_CLAUSE,
+    WHERE_PRED,
     ABI,
     NAME,
     NAME_REF,
@@ -415,6 +416,7 @@ impl SyntaxKind {
             ALIAS => &SyntaxInfo { name: "ALIAS" },
             VISIBILITY => &SyntaxInfo { name: "VISIBILITY" },
             WHERE_CLAUSE => &SyntaxInfo { name: "WHERE_CLAUSE" },
+            WHERE_PRED => &SyntaxInfo { name: "WHERE_PRED" },
             ABI => &SyntaxInfo { name: "ABI" },
             NAME => &SyntaxInfo { name: "NAME" },
             NAME_REF => &SyntaxInfo { name: "NAME_REF" },