Where clauses

9 files changed, 162 insertions, 27 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" },
diff --git a/tests/data/parser/inline/0016_type_item_where_clause.txt b/tests/data/parser/inline/0016_type_item_where_clause.txt
index 5879edc42..2f3c52960 100644
--- a/tests/data/parser/inline/0016_type_item_where_clause.txt
+++ b/tests/data/parser/inline/0016_type_item_where_clause.txt
@@ -8,10 +8,19 @@ FILE@[0; 31)
     WHERE_CLAUSE@[9; 24)
       WHERE_KW@[9; 14)
       WHITESPACE@[14; 15)
-      IDENT@[15; 18) "Foo"
-      COLON@[18; 19)
-      WHITESPACE@[19; 20)
-      IDENT@[20; 24) "Copy"
+      WHERE_PRED@[15; 24)
+        PATH_TYPE@[15; 18)
+          PATH@[15; 18)
+            PATH_SEGMENT@[15; 18)
+              NAME_REF@[15; 18)
+                IDENT@[15; 18) "Foo"
+        COLON@[18; 19)
+        WHITESPACE@[19; 20)
+        PATH@[20; 24)
+          PATH_SEGMENT@[20; 24)
+            NAME_REF@[20; 24)
+              IDENT@[20; 24) "Copy"
+              err: `expected COMMA`
     WHITESPACE@[24; 25)
     EQ@[25; 26)
     WHITESPACE@[26; 27)
diff --git a/tests/data/parser/inline/0056_trait_item.txt b/tests/data/parser/inline/0056_trait_item.txt
index b2d36afe7..ba4e0ebc8 100644
--- a/tests/data/parser/inline/0056_trait_item.txt
+++ b/tests/data/parser/inline/0056_trait_item.txt
@@ -27,10 +27,18 @@ FILE@[0; 42)
     WHERE_CLAUSE@[25; 38)
       WHERE_KW@[25; 30)
       WHITESPACE@[30; 31)
-      IDENT@[31; 32) "U"
-      COLON@[32; 33)
-      WHITESPACE@[33; 34)
-      IDENT@[34; 38) "Copy"
+      WHERE_PRED@[31; 38)
+        PATH_TYPE@[31; 32)
+          PATH@[31; 32)
+            PATH_SEGMENT@[31; 32)
+              NAME_REF@[31; 32)
+                IDENT@[31; 32) "U"
+        COLON@[32; 33)
+        WHITESPACE@[33; 34)
+        PATH@[34; 38)
+          PATH_SEGMENT@[34; 38)
+            NAME_REF@[34; 38)
+              IDENT@[34; 38) "Copy"
     WHITESPACE@[38; 39)
     L_CURLY@[39; 40)
     R_CURLY@[40; 41)
diff --git a/tests/data/parser/inline/0059_fn_item_where_clause.txt b/tests/data/parser/inline/0059_fn_item_where_clause.txt
index 8614d1597..afedf983e 100644
--- a/tests/data/parser/inline/0059_fn_item_where_clause.txt
+++ b/tests/data/parser/inline/0059_fn_item_where_clause.txt
@@ -17,10 +17,18 @@ FILE@[0; 29)
     WHERE_CLAUSE@[12; 25)
       WHERE_KW@[12; 17)
       WHITESPACE@[17; 18)
-      IDENT@[18; 19) "T"
-      COLON@[19; 20)
-      WHITESPACE@[20; 21)
-      IDENT@[21; 25) "Copy"
+      WHERE_PRED@[18; 25)
+        PATH_TYPE@[18; 19)
+          PATH@[18; 19)
+            PATH_SEGMENT@[18; 19)
+              NAME_REF@[18; 19)
+                IDENT@[18; 19) "T"
+        COLON@[19; 20)
+        WHITESPACE@[20; 21)
+        PATH@[21; 25)
+          PATH_SEGMENT@[21; 25)
+            NAME_REF@[21; 25)
+              IDENT@[21; 25) "Copy"
     WHITESPACE@[25; 26)
     BLOCK_EXPR@[26; 28)
       L_CURLY@[26; 27)
diff --git a/tests/data/parser/inline/0098_where_clause.rs b/tests/data/parser/inline/0098_where_clause.rs
new file mode 100644
index 000000000..592a005f9
--- /dev/null
+++ b/tests/data/parser/inline/0098_where_clause.rs
@@ -0,0 +1,6 @@
+fn foo()
+where
+   'a: 'b + 'c,
+   T: Clone + Copy + 'static,
+   Iterator::Item: 'a,
+{}
diff --git a/tests/data/parser/inline/0098_where_clause.txt b/tests/data/parser/inline/0098_where_clause.txt
new file mode 100644
index 000000000..a1180b554
--- /dev/null
+++ b/tests/data/parser/inline/0098_where_clause.txt
@@ -0,0 +1,69 @@
+FILE@[0; 87)
+  FN_ITEM@[0; 86)
+    FN_KW@[0; 2)
+    WHITESPACE@[2; 3)
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7)
+      R_PAREN@[7; 8)
+    WHITESPACE@[8; 9)
+    WHERE_CLAUSE@[9; 83)
+      WHERE_KW@[9; 14)
+      WHITESPACE@[14; 18)
+      WHERE_PRED@[18; 29)
+        LIFETIME@[18; 20) "'a"
+        COLON@[20; 21)
+        WHITESPACE@[21; 22)
+        LIFETIME@[22; 24) "'b"
+        WHITESPACE@[24; 25)
+        PLUS@[25; 26)
+        WHITESPACE@[26; 27)
+        LIFETIME@[27; 29) "'c"
+      COMMA@[29; 30)
+      WHITESPACE@[30; 34)
+      WHERE_PRED@[34; 59)
+        PATH_TYPE@[34; 35)
+          PATH@[34; 35)
+            PATH_SEGMENT@[34; 35)
+              NAME_REF@[34; 35)
+                IDENT@[34; 35) "T"
+        COLON@[35; 36)
+        WHITESPACE@[36; 37)
+        PATH@[37; 42)
+          PATH_SEGMENT@[37; 42)
+            NAME_REF@[37; 42)
+              IDENT@[37; 42) "Clone"
+        WHITESPACE@[42; 43)
+        PLUS@[43; 44)
+        WHITESPACE@[44; 45)
+        PATH@[45; 49)
+          PATH_SEGMENT@[45; 49)
+            NAME_REF@[45; 49)
+              IDENT@[45; 49) "Copy"
+        WHITESPACE@[49; 50)
+        PLUS@[50; 51)
+        WHITESPACE@[51; 52)
+        LIFETIME@[52; 59) "'static"
+      COMMA@[59; 60)
+      WHITESPACE@[60; 64)
+      WHERE_PRED@[64; 82)
+        PATH_TYPE@[64; 78)
+          PATH@[64; 78)
+            PATH@[64; 72)
+              PATH_SEGMENT@[64; 72)
+                NAME_REF@[64; 72)
+                  IDENT@[64; 72) "Iterator"
+            COLONCOLON@[72; 74)
+            PATH_SEGMENT@[74; 78)
+              NAME_REF@[74; 78)
+                IDENT@[74; 78) "Item"
+        COLON@[78; 79)
+        WHITESPACE@[79; 80)
+        LIFETIME@[80; 82) "'a"
+      COMMA@[82; 83)
+    WHITESPACE@[83; 84)
+    BLOCK_EXPR@[84; 86)
+      L_CURLY@[84; 85)
+      R_CURLY@[85; 86)
+  WHITESPACE@[86; 87)