Initial parser changes for the new directive syntax

compiler/java/com/google/dart/compiler/ast/DartPartOfDirective.java

Index: compiler/java/com/google/dart/compiler/ast/DartPartOfDirective.java
===================================================================
--- compiler/java/com/google/dart/compiler/ast/DartPartOfDirective.java	(revision 0)
+++ compiler/java/com/google/dart/compiler/ast/DartPartOfDirective.java	(revision 0)
@@ -0,0 +1,34 @@
+// Copyright (c) 2012, 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.
+
+package com.google.dart.compiler.ast;
+
+/**
+ * Implements the "part of" directive.
+ */
+public class DartPartOfDirective extends DartDirective {
+  private DartExpression name;
+
+  public DartPartOfDirective(DartExpression name) {
+    this.name = becomeParentOf(name);
+  }
+
+  public DartExpression getName() {
+    return name;
+  }
+
+  public String getLibraryName() {
+    return name == null ? null : name.toSource();
+  }
+
+  @Override
+  public void visitChildren(ASTVisitor<?> visitor) {
+    safelyVisitChild(name, visitor);
+  }
+
+  @Override
+  public <R> R accept(ASTVisitor<R> visitor) {
+    return visitor.visitPartOfDirective(this);
+  }
+}