Add Sass media query classes.

lib/src/ast/sass/media_query.dart

@@ -0,0 +1,48 @@
+// Copyright 2016 Google Inc. Use of this source code is governed by an
+// MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
+import 'package:source_span/source_span.dart';
+
+import '../../utils.dart';
+import '../node.dart';
+import 'expression.dart';
+import 'node.dart';
+
+class MediaQuery implements SassNode {
+  final InterpolationExpression modifier;
+
+  final InterpolationExpression type;
+
+  final List<InterpolationExpression> features;
+
+  FileSpan get span {
+    var components = <AstNode>[];
+    if (modifier != null) components.add(modifier);
+    if (type != null) components.add(type);
+    components.addAll(features);
+    return spanForList(components);
+  }
+
+  MediaQuery(this.type, {this.modifier,
+      Iterable<InterpolationExpression> features})
+      : features = features == null
+            ? const []
+            : new List.unmodifiable(features);
+
+  MediaQuery.condition(Iterable<InterpolationExpression> features,
+      {this.modifier, this.type})
+      : features = new List.unmodifiable(features);
+
+  String toString() {
+    var buffer = new StringBuffer();
+    if (modifier != null) buffer.write("$modifier ");
+    if (type != null) {
+      buffer.write(type);
+      if (features.isNotEmpty) buffer.write(" and ");
+    }
+
+    buffer.write(features.join(" and "));
+    return buffer.toString();
+  }
+}

lib/src/ast/sass/media_rule.dart

@@ -0,0 +1,26 @@
+// Copyright 2016 Google Inc. Use of this source code is governed by an
+// MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
+import 'package:source_span/source_span.dart';
+
+import '../../visitor/sass/statement.dart';
+import 'statement.dart';
+
+class MediaRule implements Statement {
+  final List<MediaQuery> queries;
+
+  final List<Statement> children;
+
+  final FileSpan span;
+
+  MediaRule(Iterable<MediaQuery> queries, Iterable<Statement> children,
+      {this.span})
+      : queries = new List.unmodifiable(queries),
+        children = new List.unmodifiable(children);
+
+  /*=T*/ accept/*<T>*/(StatementVisitor/*<T>*/ visitor) =>
+      visitor.visitMediaRule(this);
+
+  String toString() => "@media ${queries.join(", ")} {${children.join(" ")}}";
+}

lib/src/ast/sass/statement.dart

@@ -8,6 +8,8 @@ import 'node.dart';
 export 'at_rule.dart';
 export 'comment.dart';
 export 'declaration.dart';
+export 'media_query.dart';
+export 'media_rule.dart';
 export 'style_rule.dart';
 export 'stylesheet.dart';
 export 'variable_declaration.dart';

lib/src/parser.dart

@@ -108,6 +108,11 @@ class Parser {
     var name = _identifier();
     _ignoreComments();
 
+    if (name == "media") {
+      return new MediaRule(_mediaQueryList(), _ruleChildren(),
+          span: _scanner.spanFrom(start));
+    }
+
     InterpolationExpression value;
     var next = _scanner.peekChar();
     if (next != $exclamation && next != $semicolon && next != $lbrace &&
@@ -969,19 +974,16 @@ class Parser {
 
   // ## Media Queries
 
-  MediaQueryList _mediaQueryList() {
-    var start = _scanner.state;
+  List<MediaQuery> _mediaQueryList() {
     var queries = <MediaQuery>[];
     do {
       _ignoreComments();
       queries.add(_mediaQuery());
     } while (_scanner.scanChar($comma));
-    return new MediaQueryList(queries, span: _scanner.spanFrom(start));
+    return queries;
   }
 
   MediaQuery _mediaQuery() {
-    var start = _scanner.state;
-
     InterpolationExpression modifier;
     InterpolationExpression type;
     if (_scanner.peekChar() != $lparen) {
@@ -990,7 +992,7 @@ class Parser {
 
       if (!_lookingAtInterpolatedIdentifier()) {
         // For example, "@media screen {"
-        return new MediaQuery(identifier1, span: _scanner.spanFrom(start));
+        return new MediaQuery(identifier1);
       }
 
       var identifier2 = _interpolatedIdentifier();
@@ -1007,8 +1009,7 @@ class Parser {
           _ignoreComments();
         } else {
           // For example, "@media only screen {"
-          return new MediaQuery(type,
-              modifier: modifier, span: _scanner.spanFrom(start));
+          return new MediaQuery(type, modifier: modifier);
         }
       }
     }
@@ -1016,18 +1017,16 @@ class Parser {
     // We've consumed either `IDENTIFIER "and"` or
     // `IDENTIFIER IDENTIFIER "and"`.
 
-    var expressions = <InterpolationExpression>[];
+    var features = <InterpolationExpression>[];
     do {
       _ignoreComments();
-      expressions.add(_mediaExpression());
+      features.add(_mediaExpression());
     } while (_scanCaseInsensitive("and"));
 
     if (type == null) {
-      return new MediaQuery.expressions(expressions,
-          span: _scanner.spanFrom(start));
+      return new MediaQuery.condition(features);
     } else {
-      return new MediaQuery(type, modifier: modifier, expressions: expressions,
-          span: _scanner.spanFrom(start));
+      return new MediaQuery(type, modifier: modifier, features: features);
     }
   }
 

lib/src/visitor/sass/statement.dart

@@ -17,6 +17,13 @@ class StatementVisitor<T> {
     return null;
   }
 
+  T visitMediaRule(MediaRule node) {
+    for (var child in node.children) {
+      child.accept(this);
+    }
+    return null;
+  }
+
   T visitStyleRule(StyleRule node) {
     for (var child in node.children) {
       child.accept(this);