Support for @mixin, @include and @extend

pkg/csslib/lib/src/css_printer.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of csslib.visitor;
 
 /**
  * Visitor that produces a formatted string representation of the CSS tree.
  */
 class CssPrinter extends Visitor {
@@ skipping 169 matching lines @@
       }
     }
     emit(';');
   }
 
   void visitVarDefinitionDirective(VarDefinitionDirective node) {
     visitVarDefinition(node.def);
     emit(';$_newLine');
   }
 
+  void visitMixinRulesetDirective(MixinRulesetDirective node) {
+    emit('@mixin ${node.name} {');
+    for (var ruleset in node.rulesets) {
+      ruleset.visit(this);
+    }
+    emit('}');
+  }
+
+  void visitMixinDeclarationDirective(MixinDeclarationDirective node) {
+    emit('@mixin ${node.name} {\n');
+    visitDeclarationGroup(node.declarations);
+    emit('}');
+  }
+
+  /**
+   * Added optional newLine for handling @include at top-level vs/ inside of
+   * a declaration group.
+   */
+  void visitIncludeDirective(IncludeDirective node, [bool topLevel = true]) {
+    if (topLevel) emit(_newLine);
+    emit('@include ${node.name}');
+    emit(';');
+  }
+
+  void visitContentDirective(ContentDirective node) {
+    // TODO(terry): TBD
+  }
+
   void visitRuleSet(RuleSet node) {
     emit("$_newLine");
     node._selectorGroup.visit(this);
     emit(" {$_newLine");
     node._declarationGroup.visit(this);
     emit("}");
   }
 
   void visitDeclarationGroup(DeclarationGroup node) {
     var declarations = node._declarations;
@@ skipping 25 matching lines @@
     node._expression.visit(this);
 
     emit("${importantAsString()}");
   }
 
   void visitVarDefinition(VarDefinition node) {
     emit("var-${node.definedName}: ");
     node._expression.visit(this);
   }
 
+  void visitIncludeMixinAtDeclaration(IncludeMixinAtDeclaration node) {
+    // Don't emit a new line we're inside of a declaration group.
+    visitIncludeDirective(node.include, false);
+  }
+
+  void visitExtendDeclaration(ExtendDeclaration node) {
+    emit("@extend ");
+    for (var selector in node.selectors) {
+      selector.visit(this);
+    }
+  }
+
+
   void visitSelectorGroup(SelectorGroup node) {
     var selectors = node._selectors;
     var selectorsLength = selectors.length;
     for (var i = 0; i < selectorsLength; i++) {
       if (i > 0) emit(',$_sp');
       selectors[i].visit(this);
     }
   }
 
   void visitSimpleSelectorSequence(SimpleSelectorSequence node) {
     emit('${node._combinatorToString}');
     node._selector.visit(this);
   }
 
   void visitSimpleSelector(SimpleSelector node) {
     emit(node.name);
   }
 
   void visitNamespaceSelector(NamespaceSelector node) {
-    emit("${node.namespace}|${node.nameAsSimpleSelector.name}");
+    emit(node.toString());
   }
 
   void visitElementSelector(ElementSelector node) {
-    emit("${node.name}");
+    emit(node.toString());
   }
 
   void visitAttributeSelector(AttributeSelector node) {
-    emit("[${node.name}${node.matchOperator()}${node.valueToString()}]");
+    emit(node.toString());
   }
 
   void visitIdSelector(IdSelector node) {
-    emit("#${node.name}");
+    emit(node.toString());
   }
 
   void visitClassSelector(ClassSelector node) {
-    emit(".${node.name}");
+    emit(node.toString());
   }
 
   void visitPseudoClassSelector(PseudoClassSelector node) {
-    emit(":${node.name}");
+    emit(node.toString());
   }
 
   void visitPseudoElementSelector(PseudoElementSelector node) {
-    emit("::${node.name}");
+    emit(node.toString());
   }
 
   void visitPseudoClassFunctionSelector(PseudoClassFunctionSelector node) {
     emit(":${node.name}(");
     node.expression.visit(this);
     emit(')');
   }
 
   void visitPseudoElementFunctionSelector(PseudoElementFunctionSelector node) {
     emit("::${node.name}(");
@@ skipping 178 matching lines @@
 
   void visitWildcard(Wildcard node) {
     emit('*');
   }
 
   void visitDartStyleExpression(DartStyleExpression node) {
     // TODO(terry): TBD
     throw UnimplementedError;
   }
 }