Drop support for the reference combinator.

CHANGELOG.md

@@ -1,5 +1,8 @@
 ## 1.0.0-alpha.10
 
+* Drop support for the reference combinator. This has been removed from the
+  spec, and will be deprecated and eventually removed in other implementations.
+
 * Trust type annotations when compiling to JavaScript, which makes it
   substantially faster.
 

README.md

@@ -173,6 +173,8 @@ Sass to update the reference behavior.
     where they wouldn't be in Ruby Sass. This better matches the semantics of
     the selectors in question, and is more efficient. See [issue 2228][].
 
+12. The reference combinator is not supported. See [issue 303][].
+
 [issue 1599]: https://github.com/sass/sass/issues/1599
 [issue 1126]: https://github.com/sass/sass/issues/1126
 [issue 2120]: https://github.com/sass/sass/issues/2120
@@ -184,5 +186,6 @@ Sass to update the reference behavior.
 [issue 1408]: https://github.com/sass/sass/issues/1408
 [issue 1050]: https://github.com/sass/sass/issues/1050
 [issue 2228]: https://github.com/sass/sass/issues/2228
+[issue 303]: https://github.com/sass/sass/issues/303
 
 Disclaimer: this is not an official Google product.

lib/src/ast/selector/complex.dart

@@ -121,15 +121,3 @@ class Combinator implements ComplexSelectorComponent {
 
   String toString() => _text;
 }
-
-/// A reference combinator, like `/for/`.
-class ReferenceCombinator implements Combinator {
-  /// The name of the attribute being selected for.
-  final String name;
-
-  String get _text => "/$name/";
-
-  ReferenceCombinator(this.name);
-
-  String toString() => _text;
-}

lib/src/parse/selector.dart

@@ -94,12 +94,6 @@ class SelectorParser extends Parser {
           components.add(Combinator.followingSibling);
           break;
 
-        case $slash:
-          scanner.readChar();
-          components.add(new ReferenceCombinator(identifier()));
-          scanner.expectChar($slash);
-          break;
-
         case $lbracket:
         case $dot:
         case $hash: