Initial support for hide and show in import directives

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

Index: compiler/java/com/google/dart/compiler/ast/ImportShowCombinator.java
===================================================================
--- compiler/java/com/google/dart/compiler/ast/ImportShowCombinator.java	(revision 0)
+++ compiler/java/com/google/dart/compiler/ast/ImportShowCombinator.java	(revision 0)
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2012, the Dart project authors.
+ * 
+ * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ * 
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.dart.compiler.ast;
+
+/**
+ * Instances of the class <code>ImportShowCombinator</code> represent a combinator that restricts
+ * the names being imported to those in a given list.
+ * 
+ * <pre>
+ * importShowCombinator ::=
+ *     'show:' {@link DartArrayLiteral listLiteral}
+ * </pre>
+ */
+public class ImportShowCombinator extends ImportCombinator {
+  /**
+   * The list of names from the library that are made visible by this combinator.
+   */
+  private DartArrayLiteral shownNames;
+
+  /**
+   * Initialize a newly created import show combinator.
+   */
+  public ImportShowCombinator() {
+    super();
+  }
+
+  /**
+   * Initialize a newly created import show combinator.
+   * 
+   * @param shownNames the list of names from the library that are made visible by this combinator
+   */
+  public ImportShowCombinator(DartArrayLiteral shownNames) {
+    this.shownNames = becomeParentOf(shownNames);
+  }
+
+  @Override
+  public <R> R accept(ASTVisitor<R> visitor) {
+    return visitor.visitImportShowCombinator(this);
+  }
+
+  /**
+   * Return the list of names from the library that are made visible by this combinator.
+   * 
+   * @return the list of names from the library that are made visible by this combinator
+   */
+  public DartArrayLiteral getShownNames() {
+    return shownNames;
+  }
+
+  /**
+   * Set the list of names from the library that are made visible by this combinator to the given
+   * list.
+   * 
+   * @param shownNames the list of names from the library that are made visible by this combinator
+   */
+  public void setShownNames(DartArrayLiteral shownNames) {
+    this.shownNames = becomeParentOf(shownNames);
+  }
+
+  @Override
+  public void visitChildren(ASTVisitor<?> visitor) {
+    if (shownNames != null) {
+      shownNames.visitChildren(visitor);
+    }
+  }
+}