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diff --git a/lrparser/org.eclipse.cdt.core.lrparser/src/org/eclipse/cdt/core/dom/lrparser/action/ITokenStream.java b/lrparser/org.eclipse.cdt.core.lrparser/src/org/eclipse/cdt/core/dom/lrparser/action/ITokenStream.java
new file mode 100644
index 00000000000..9012e63c9ad
--- /dev/null
+++ b/lrparser/org.eclipse.cdt.core.lrparser/src/org/eclipse/cdt/core/dom/lrparser/action/ITokenStream.java
@@ -0,0 +1,69 @@
+/*******************************************************************************
+ * Copyright (c) 2006, 2009 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.core.dom.lrparser.action;
+
+import java.util.List;
+
+import lpg.lpgjavaruntime.IToken;
+
+/**
+ * Provides an interface to the token stream that
+ * can be used by the parser semantic actions.
+ * 
+ * Allows the semantic actions to directly inspect the token 
+ * stream. Used to calculate AST node offsets and for 
+ * other purposes.
+ * 
+ * TODO There are still issues with getLeftIToken() and 
+ * getRightIToken(), they should return null when used with
+ * an empty rule but currently they don't.
+ * 
+ * @author Mike Kucera
+ */
+public interface ITokenStream {
+	
+	/**
+	 * Returns the tokens that were parsed to recognized
+	 * the currently executing rule.
+	 * 
+	 * @returns a read-only list of tokens, will not be null but may be empty
+	 */
+	public List<IToken> getRuleTokens();
+	
+	/**
+	 * Usually equivalent to getRuleTokens().get(0); but more efficient.
+	 * 
+	 * However, when called during an empty rule it will return the token to the
+	 * left of the location of the empty rule.
+	 */
+	public IToken getLeftIToken();
+	
+	/**
+	 * Usually equivalent to getRuleTokens().get(getRuleTokens().size()-1); but more efficient.
+	 * 
+	 * However, when called during an empty rule it will return the token to the
+	 * right of the location of the empty rule.
+	 */
+	public IToken getRightIToken(); 
+	
+
+	/**
+	 * Returns the orderedTerminalSymbol field of the corresponding sym class
+	 * generated by LPG.
+	 */
+	public String[] getOrderedTerminalSymbols();
+	
+	
+	/**
+	 * Returns the parser's name, useful for debugging.
+	 */
+	public String getName();
+}