Constant evaluation support

editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/object/TypeState.java

Index: editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/object/TypeState.java
diff --git a/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/object/TypeState.java b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/object/TypeState.java
new file mode 100644
index 0000000000000000000000000000000000000000..59c79b5c55f9717bac06a9eda1877525bea938ae
--- /dev/null
+++ b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/object/TypeState.java
@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2013, 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.engine.internal.object;
+
+import com.google.dart.engine.element.Element;
+import com.google.dart.engine.utilities.general.ObjectUtilities;
+
+/**
+ * Instances of the class {@code TypeState} represent the state of an object representing a type.
+ */
+public class TypeState extends InstanceState {
+  /**
+   * The element representing the type being modeled.
+   */
+  private Element element;
+
+  /**
+   * Initialize a newly created state to represent the given value.
+   * 
+   * @param element the element representing the type being modeled
+   */
+  public TypeState(Element element) {
+    this.element = element;
+  }
+
+  @Override
+  public StringState convertToString() throws EvaluationException {
+    if (element == null) {
+      return StringState.UNKNOWN_VALUE;
+    }
+    return new StringState(element.getName());
+  }
+
+  @Override
+  public boolean equals(Object object) {
+    return object instanceof TypeState
+        && ObjectUtilities.equals(element, ((TypeState) object).element);
+  }
+
+  @Override
+  public BoolState equalEqual(InstanceState rightOperand) throws EvaluationException {
+    assertBoolNumStringOrNull(rightOperand);
+    if (element == null) {
+      return BoolState.UNKNOWN_VALUE;
+    }
+    if (rightOperand instanceof TypeState) {
+      Element rightElement = ((TypeState) rightOperand).element;
+      if (rightElement == null) {
+        return BoolState.UNKNOWN_VALUE;
+      }
+      return BoolState.from(element.equals(rightElement));
+    } else if (rightOperand instanceof DynamicState) {
+      return BoolState.UNKNOWN_VALUE;
+    }
+    return BoolState.FALSE_STATE;
+  }
+
+  @Override
+  public String getTypeName() {
+    return "Type"; //$NON-NLS-0$
+  }
+
+  @Override
+  public int hashCode() {
+    return element == null ? 0 : element.hashCode();
+  }
+
+  @Override
+  public String toString() {
+    return element == null ? "-unknown-" : element.getName();
+  }
+}