Initial implementation of MemoryIndexStoreImpl and IndexContributor.

editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/ast/SimpleIdentifier.java

Index: editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/ast/SimpleIdentifier.java
diff --git a/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/ast/SimpleIdentifier.java b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/ast/SimpleIdentifier.java
index a75768c6a4a4f890a65cd21759dd8c3f72defe34..d57b5f3c8b097b55a130d1cb638e789f29317eb2 100644
--- a/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/ast/SimpleIdentifier.java
+++ b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/ast/SimpleIdentifier.java
@@ -14,6 +14,7 @@
 package com.google.dart.engine.ast;
 
 import com.google.dart.engine.scanner.Token;
+import com.google.dart.engine.scanner.TokenType;
 
 /**
  * Instances of the class {@code SimpleIdentifier} represent a simple identifier.
@@ -71,6 +72,36 @@ public class SimpleIdentifier extends Identifier {
     return token;
   }
 
+  /**
+   * Looks to see if this identifier is used to read value.
+   */
+  public boolean inGetterContext() {
+    if (getParent() instanceof AssignmentExpression) {
+      AssignmentExpression expr = (AssignmentExpression) getParent();
+      if (expr.getLeftHandSide() == this && expr.getOperator().getType() == TokenType.EQ) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  /**
+   * Looks to see if this identifier is used to write value.
+   */
+  public boolean inSetterContext() {
+    if (getParent() instanceof PrefixExpression) {
+      PrefixExpression expr = (PrefixExpression) getParent();
+      return expr.getOperand() == this && expr.getOperator().getType().isIncrementOperator();
+    }
+    if (getParent() instanceof PostfixExpression) {
+      return true;
+    }
+    if (getParent() instanceof AssignmentExpression) {
+      return true;

[Brian Wilkerson, 2013/01/07 23:10:10]

Doesn't this need to check that the identifier is on the left-hand side? In the
expression "a = b" I would expect the node for "b" to return false.

[scheglov, 2013/01/07 23:21:35]

Done.

+    }
+    return false;
+  }
+
   @Override
   public boolean isSynthetic() {
     return token.isSynthetic();