Support for @mixin, @include and @extend

pkg/csslib/lib/src/css_printer.dart

Index: pkg/csslib/lib/src/css_printer.dart
diff --git a/pkg/csslib/lib/src/css_printer.dart b/pkg/csslib/lib/src/css_printer.dart
index b8000b70a7ea9c40fafdd677aec303d4b312e7fc..d2c8111803add6e1e96d597bcf7868ffa86f9579 100644
--- a/pkg/csslib/lib/src/css_printer.dart
+++ b/pkg/csslib/lib/src/css_printer.dart
@@ -187,6 +187,34 @@ class CssPrinter extends Visitor {
     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 newline for top-level @include.

[nweiz, 2013/09/18 22:40:54]

Unnecessary spaces before the comment.

[terry, 2013/10/09 03:40:33]

Done.

+    emit('@include ${node.name}');
+    if (topLevel) emit(';');

[nweiz, 2013/09/18 22:40:54]

Why wouldn't non-top-level @includes have a semicolon?

[terry, 2013/10/09 03:40:33]

removed test.On 2013/09/18 22:40:54, nweiz wrote:

+  }
+
+  void visitContentDirective(ContentDirective node) {

[nweiz, 2013/09/18 22:40:54]

If you don't support content directives yet, just don't include the code.

[terry, 2013/10/09 03:40:33]

Place holder have errors for content directive in parser.  Don't want to forget
content printer.
On 2013/09/18 22:40:54, nweiz wrote:

+    // TODO(terry): TBD
+  }
+
   void visitRuleSet(RuleSet node) {
     emit("$_newLine");
     node._selectorGroup.visit(this);
@@ -232,6 +260,11 @@ class CssPrinter extends Visitor {
     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 visitSelectorGroup(SelectorGroup node) {
     var selectors = node._selectors;
     var selectorsLength = selectors.length;