/*******************************************************************************
 * Copyright (c) 2003, 2004 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.cdt.internal.core.parser;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Stack;

import org.eclipse.cdt.core.parser.BacktrackException;
import org.eclipse.cdt.core.parser.EndOfFileException;
import org.eclipse.cdt.core.parser.IParserLogService;
import org.eclipse.cdt.core.parser.IProblem;
import org.eclipse.cdt.core.parser.IScanner;
import org.eclipse.cdt.core.parser.IToken;
import org.eclipse.cdt.core.parser.ITokenDuple;
import org.eclipse.cdt.core.parser.KeywordSetKey;
import org.eclipse.cdt.core.parser.OffsetLimitReachedException;
import org.eclipse.cdt.core.parser.ParseError;
import org.eclipse.cdt.core.parser.ParserFactory;
import org.eclipse.cdt.core.parser.ParserLanguage;
import org.eclipse.cdt.core.parser.ParserMode;
import org.eclipse.cdt.core.parser.ScannerException;
import org.eclipse.cdt.core.parser.ast.ASTPointerOperator;
import org.eclipse.cdt.core.parser.ast.ASTSemanticException;
import org.eclipse.cdt.core.parser.ast.IASTArrayModifier;
import org.eclipse.cdt.core.parser.ast.IASTCompletionNode;
import org.eclipse.cdt.core.parser.ast.IASTExpression;
import org.eclipse.cdt.core.parser.ast.IASTFactory;
import org.eclipse.cdt.core.parser.ast.IASTNode;
import org.eclipse.cdt.core.parser.ast.IASTScope;
import org.eclipse.cdt.core.parser.ast.IASTSimpleTypeSpecifier;
import org.eclipse.cdt.core.parser.ast.IASTTypeId;
import org.eclipse.cdt.core.parser.ast.IASTCompletionNode.CompletionKind;
import org.eclipse.cdt.core.parser.ast.IASTExpression.Kind;
import org.eclipse.cdt.core.parser.extension.IParserExtension;
import org.eclipse.cdt.internal.core.parser.token.TokenFactory;
import org.eclipse.cdt.internal.core.parser.util.TraceUtil;

/**
 * @author jcamelon
 */
public class ExpressionParser implements IExpressionParser, IParserData {

	protected static final String EMPTY_STRING = ""; //$NON-NLS-1$
	private static int FIRST_ERROR_UNSET = -1;
	protected boolean parsePassed = true;
	protected int firstErrorOffset = FIRST_ERROR_UNSET;
	protected int firstErrorLine = FIRST_ERROR_UNSET;
	private BacktrackException backtrack = new BacktrackException();
	private int backtrackCount = 0;

	protected final void throwBacktrack( IProblem problem ) throws BacktrackException {
		++backtrackCount;
		backtrack.initialize( problem );
		throw backtrack;
	}

	protected final void throwBacktrack( int startingOffset, int endingOffset, int lineNumber ) throws BacktrackException {
		++backtrackCount;		
		backtrack.initialize( startingOffset, ( endingOffset == 0 ) ? startingOffset + 1 : endingOffset, lineNumber );
		throw backtrack;
	}

	protected final IParserExtension extension;

	//TODO this stuff needs to be encapsulated by IParserData
	protected final IParserLogService log;
	protected ParserLanguage language = ParserLanguage.CPP;
	protected IASTFactory astFactory = null;
	protected IScanner scanner;
	protected IToken currToken;
	protected IToken lastToken;
	private boolean limitReached = false;
	private Stack templateIdScopes = null;
	private TypeId typeIdInstance = new TypeId();

	/**
	 * @return Returns the astFactory.
	 */
	public IASTFactory getAstFactory() {
		return astFactory;
	}
	/**
	 * @return Returns the log.
	 */
	public IParserLogService getLog() {
		return log;
	}

	/**
	 * Look Ahead in the token list to see what is coming.  
	 * 
	 * @param i		How far ahead do you wish to peek?
	 * @return		the token you wish to observe
	 * @throws EndOfFileException	if looking ahead encounters EOF, throw EndOfFile 
	 */
	public IToken LA(int i) throws EndOfFileException {

		if (parserTimeout()) {
			throw new ParseError(ParseError.ParseErrorKind.TIMEOUT);
		}

		if (i < 1) // can't go backwards
			return null;
		if (currToken == null)
			currToken = fetchToken();
		IToken retToken = currToken;
		for (; i > 1; --i) {
			retToken = retToken.getNext();
			if (retToken == null)
				retToken = fetchToken();
		}
		return retToken;
	}

	/**
	 * Look ahead in the token list and return the token type.  
	 * 
	 * @param i				How far ahead do you wish to peek?
	 * @return				The type of that token
	 * @throws EndOfFileException	if looking ahead encounters EOF, throw EndOfFile
	 */
	public int LT(int i) throws EndOfFileException {
		return LA(i).getType();
	}

	/**
	 * Consume the next token available, regardless of the type.  
	 * 
	 * @return				The token that was consumed and removed from our buffer.  
	 * @throws EndOfFileException	If there is no token to consume.  
	 */
	public IToken consume() throws EndOfFileException {

		if (currToken == null)
			currToken = fetchToken();
		if (currToken != null)
			lastToken = currToken;
		currToken = currToken.getNext();
		handleNewToken(lastToken);
		return lastToken;
	}

	/**
	 * Consume the next token available only if the type is as specified.  
	 * 
	 * @param type			The type of token that you are expecting.  	
	 * @return				the token that was consumed and removed from our buffer. 
	 * @throws BacktrackException	If LT(1) != type 
	 */
	public IToken consume(int type) throws EndOfFileException,
			BacktrackException {
		if (LT(1) == type)
			return consume();
		IToken la = LA(1);
		throwBacktrack(la.getOffset(), la.getEndOffset(), la.getLineNumber());
		return null;
	}

	/**
	 * Mark our place in the buffer so that we could return to it should we have to.  
	 * 
	 * @return				The current token. 
	 * @throws EndOfFileException	If there are no more tokens.
	 */
	public IToken mark() throws EndOfFileException {
		if (currToken == null)
			currToken = fetchToken();
		return currToken;
	}

	/**
	 * Rollback to a previous point, reseting the queue of tokens.  
	 * 
	 * @param mark		The point that we wish to restore to.  
	 *  
	 */
	public void backup(IToken mark) {
		currToken = mark;
		lastToken = null; // this is not entirely right ... 
	}

	/**
	 * @param extension TODO
	 * @param scanner2
	 * @param callback
	 * @param language2
	 * @param log2
	 */
	public ExpressionParser(IScanner scanner, ParserLanguage language,
			IParserLogService log, IParserExtension extension) {
		this.scanner = scanner;
		this.language = language;
		this.log = log;
		this.extension = extension;
		setupASTFactory(scanner, language);
	}

	/**
	 * @param scanner
	 * @param language
	 */
	protected void setupASTFactory(IScanner scanner, ParserLanguage language) {
		astFactory = ParserFactory.createASTFactory(this,
				ParserMode.EXPRESSION_PARSE, language);
		scanner.setASTFactory(astFactory);
		astFactory.setLogger(log);
	}

	/**
	 * This is the single entry point for setting parsePassed to 
	 * false, and also making note what token offset we failed upon. 
	 * 
	 * @throws EndOfFileException
	 */
	protected void failParse() {
		try {
			if (firstErrorOffset == FIRST_ERROR_UNSET){
				firstErrorOffset = LA(1).getOffset();
				firstErrorLine = LA(1).getLineNumber();
			}
		} catch (EndOfFileException eof) {
			// do nothing
		} finally {
			parsePassed = false;
		}
	}

	/**
	 * Consumes template parameters.  
	 *
	 * @param previousLast	Previous "last" token (returned if nothing was consumed)
	 * @return				Last consumed token, or <code>previousLast</code> if nothing was consumed
	 * @throws BacktrackException	request a backtrack
	 */
	protected IToken consumeTemplateParameters(IToken previousLast)
			throws EndOfFileException, BacktrackException {
		if (language != ParserLanguage.CPP)
			return previousLast;
		int startingOffset = previousLast == null ? lastToken.getOffset() : previousLast.getOffset();
		IToken last = previousLast;
		if (LT(1) == IToken.tLT) {
			last = consume(IToken.tLT);
			// until we get all the names sorted out
			Stack scopes = new Stack();
			scopes.push(new Integer(IToken.tLT));

			while (!scopes.empty()) {
				int top;
				last = consume();

				switch (last.getType()) {
					case IToken.tGT :
						if (((Integer) scopes.peek()).intValue() == IToken.tLT) {
							scopes.pop();
						}
						break;
					case IToken.tRBRACKET :
						do {
							top = ((Integer) scopes.pop()).intValue();
						} while (!scopes.empty()
								&& (top == IToken.tGT || top == IToken.tLT));
						if (top != IToken.tLBRACKET)
							throwBacktrack(startingOffset, last.getEndOffset(), last.getLineNumber());

						break;
					case IToken.tRPAREN :
						do {
							top = ((Integer) scopes.pop()).intValue();
						} while (!scopes.empty()
								&& (top == IToken.tGT || top == IToken.tLT));
						if (top != IToken.tLPAREN)
							throwBacktrack(startingOffset, last.getEndOffset(), last.getLineNumber());

						break;
					case IToken.tLT :
					case IToken.tLBRACKET :
					case IToken.tLPAREN :
						scopes.push(new Integer(last.getType()));
						break;
				}
			}
		}
		return last;
	}

	protected List templateArgumentList(IASTScope scope,
			IASTCompletionNode.CompletionKind kind) throws EndOfFileException,
			BacktrackException {
		IToken start = LA(1);
		int startingOffset = start.getOffset();
		int startingLineNumber = start.getOffset();
		start = null;
		IASTExpression expression = null;
		List list = new LinkedList();

		boolean completedArg = false;
		boolean failed = false;

		if (templateIdScopes == null) {
			templateIdScopes = new Stack();
		}
		templateIdScopes.push(new Integer(IToken.tLT));

		while (LT(1) != IToken.tGT) {
			completedArg = false;

			IToken mark = mark();

			try {
				IASTTypeId typeId = typeId(scope, false, kind);

				expression = astFactory.createExpression(scope,
						IASTExpression.Kind.POSTFIX_TYPEID_TYPEID, null, null,
						null, typeId, null, EMPTY_STRING, null);
				list.add(expression);
				completedArg = true;
			} catch (BacktrackException e) {
				backup(mark);
			} catch (ASTSemanticException e) {
				backup(mark);
			}

			if (!completedArg) {
				try {
					IToken la = LA(1);
					int so = la.getOffset();
					int ln= la.getLineNumber();
					expression = assignmentExpression(scope,
							CompletionKind.VARIABLE_TYPE,
							KeywordSetKey.EXPRESSION);
					 
					if (expression.getExpressionKind() == IASTExpression.Kind.PRIMARY_EMPTY) {
						throwBacktrack(so, ( lastToken != null ) ? lastToken.getEndOffset() : 0, ln);
					}
					list.add(expression);
					completedArg = true;
				} catch (BacktrackException e) {
					backup(mark);
				}
			}
			if (!completedArg) {
				try {
					ITokenDuple nameDuple = name(scope, null,
							KeywordSetKey.EMPTY);
					expression = astFactory.createExpression(scope,
							IASTExpression.Kind.ID_EXPRESSION, null, null,
							null, null, nameDuple, EMPTY_STRING, null);
					list.add(expression);
					continue;
				} catch (ASTSemanticException e) {
					failed = true;
					break;
				} catch (BacktrackException e) {
					failed = true;
					break;
				} catch (Exception e) {
					logException("templateArgumentList::createExpression()", e); //$NON-NLS-1$
					failed = true;
					break;
				}
			}

			if (LT(1) == IToken.tCOMMA) {
				consume();
			} else if (LT(1) != IToken.tGT) {
				failed = true;
				break;
			}
		}

		templateIdScopes.pop();
		if (templateIdScopes.size() == 0) {
			templateIdScopes = null;
		}

		if (failed) {
			if (expression != null)
				expression.freeReferences(astFactory.getReferenceManager());
			throwBacktrack(startingOffset, 0, startingLineNumber );
		}

		return list;
	}

	/**
	 * Parse a template-id, according to the ANSI C++ spec.  
	 * 
	 * template-id: template-name < template-argument-list opt >
	 * template-name : identifier
	 * 
	 * @return		the last token that we consumed in a successful parse 
	 * 
	 * @throws BacktrackException	request a backtrack
	 */
	protected IToken templateId(IASTScope scope, CompletionKind kind)
			throws EndOfFileException, BacktrackException {
		ITokenDuple duple = name(scope, kind, KeywordSetKey.EMPTY);
		//IToken last = consumeTemplateParameters(duple.getLastToken());
		return duple.getLastToken();//last;
	}

	/**
	 * Parse a name.
	 * 
	 * name
	 * : ("::")? name2 ("::" name2)*
	 * 
	 * name2
	 * : IDENTIFER
	 * : template-id
	 * 
	 * @param key TODO
	 * @throws BacktrackException	request a backtrack
	 */
	protected ITokenDuple name(IASTScope scope,
			IASTCompletionNode.CompletionKind kind, KeywordSetKey key)
			throws BacktrackException, EndOfFileException {

		TemplateParameterManager argumentList = TemplateParameterManager
				.getInstance();

		try {
			IToken first = LA(1);
			IToken last = null;
			IToken mark = mark();

			boolean hasTemplateId = false;
			boolean startsWithColonColon = false;

			if (LT(1) == IToken.tCOLONCOLON) {
				argumentList.addSegment(null);
				last = consume(IToken.tCOLONCOLON);
				setCompletionValues(scope, kind, KeywordSetKey.EMPTY,
						getCompliationUnit());
				startsWithColonColon = true;
			}

			if (LT(1) == IToken.tCOMPL)
				consume();

			switch (LT(1)) {
				case IToken.tIDENTIFIER :
					IToken prev = last;
					last = consume(IToken.tIDENTIFIER);
					if (startsWithColonColon)
						setCompletionValues(scope, kind, getCompliationUnit());
					else if (prev != null)
						setCompletionValues(scope, kind, first, prev,
								KeywordSetKey.EMPTY);
					else
						setCompletionValuesNoContext(scope, kind, key);

					last = consumeTemplateArguments(scope, last, argumentList,
							kind);
					if (last.getType() == IToken.tGT)
						hasTemplateId = true;
					break;

				default :
					IToken l = LA(1);
					backup(mark);
					throwBacktrack(first.getOffset(), l.getEndOffset(), first.getLineNumber());
			}

			while (LT(1) == IToken.tCOLONCOLON) {
				IToken prev = last;
				last = consume(IToken.tCOLONCOLON);
				setCompletionValues(scope, kind, first, prev,
						KeywordSetKey.EMPTY);

				if (queryLookaheadCapability() && LT(1) == IToken.t_template)
					consume();

				if (queryLookaheadCapability() && LT(1) == IToken.tCOMPL)
					consume();

				switch (LT(1)) {
					case IToken.t_operator :
						IToken l = LA(1);
						backup(mark);
						throwBacktrack(first.getOffset(), l.getEndOffset(), first.getLineNumber());
					case IToken.tIDENTIFIER :
						prev = last;
						last = consume();
						setCompletionValues(scope, kind, first, prev,
								KeywordSetKey.EMPTY);
						last = consumeTemplateArguments(scope, last,
								argumentList, kind);
						if (last.getType() == IToken.tGT)
							hasTemplateId = true;
				}
			}

			ITokenDuple tokenDuple = TokenFactory.createTokenDuple(first, last,
					(hasTemplateId
							? argumentList.getTemplateArgumentsList()
							: null));
			setGreaterNameContext(tokenDuple);
			return tokenDuple;
		} finally {
			TemplateParameterManager.returnInstance(argumentList);
		}

	}

	/**
	 * @param scope
	 * @param kind
	 * @param key
	 */
	protected void setCompletionValuesNoContext(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws EndOfFileException {
	}
	/**
	 * @param tokenDuple
	 */
	protected void setGreaterNameContext(ITokenDuple tokenDuple) {
		//do nothing in this implementation
	}

	/**
	 * @param scope
	 * @param kind
	 */
	protected void setCompletionValues(IASTScope scope, CompletionKind kind,
			IASTNode context) throws EndOfFileException {
	}

	/**
	 * @param scope
	 * @param kind
	 */
	protected void setCompletionValues(IASTScope scope, CompletionKind kind)
			throws EndOfFileException {
	}

	/**
	 * @return
	 */
	protected IASTNode getCompliationUnit() {
		return null;
	}

	/**
	 * @param scope
	 * @param kind
	 * @param key
	 * @param node
	 */
	protected void setCompletionValues(IASTScope scope, CompletionKind kind,
			KeywordSetKey key, IASTNode node) throws EndOfFileException {
	}

	/**
	 * @param scope
	 * @param last
	 * @param argumentList
	 * @return
	 * @throws EndOfFileException
	 * @throws BacktrackException
	 */
	protected IToken consumeTemplateArguments(IASTScope scope, IToken last,
			TemplateParameterManager argumentList,
			IASTCompletionNode.CompletionKind completionKind)
			throws EndOfFileException, BacktrackException {
		if (language != ParserLanguage.CPP)
			return last;
		if (LT(1) == IToken.tLT) {
			IToken secondMark = mark();
			consume(IToken.tLT);
			try {
				List list = templateArgumentList(scope, completionKind);
				argumentList.addSegment(list);
				last = consume(IToken.tGT);
			} catch (BacktrackException bt) {
				argumentList.addSegment(null);
				backup(secondMark);
			}
		} else {
			argumentList.addSegment(null);
		}
		return last;
	}

	/**
	 * Parse a const-volatile qualifier.  
	 * 
	 * cvQualifier
	 * : "const" | "volatile"
	 * 
	 * TODO: fix this 
	 * @param ptrOp		Pointer Operator that const-volatile applies to. 		  		
	 * @return			Returns the same object sent in.
	 * @throws BacktrackException
	 */
	protected IToken cvQualifier(IDeclarator declarator)
			throws EndOfFileException, BacktrackException {
		IToken result = null;
		int startingOffset = LA(1).getOffset();
		switch (LT(1)) {
			case IToken.t_const :
				result = consume(IToken.t_const);
				declarator.addPointerOperator(ASTPointerOperator.CONST_POINTER);
				break;
			case IToken.t_volatile :
				result = consume(IToken.t_volatile);
				declarator
						.addPointerOperator(ASTPointerOperator.VOLATILE_POINTER);
				break;
			case IToken.t_restrict :
				if (language == ParserLanguage.C) {
					result = consume(IToken.t_restrict);
					declarator
							.addPointerOperator(ASTPointerOperator.RESTRICT_POINTER);
					break;
				}
				if (extension.isValidCVModifier(language, IToken.t_restrict)) {
					result = consume(IToken.t_restrict);
					declarator.addPointerOperator(extension.getPointerOperator(
							language, IToken.t_restrict));
					break;
				}
				IToken la = LA(1);
				throwBacktrack(startingOffset, la.getEndOffset(), la.getLineNumber());

			default :
				if (extension.isValidCVModifier(language, LT(1))) {
					result = consume();
					declarator.addPointerOperator(extension.getPointerOperator(
							language, result.getType()));
				}
		}
		return result;
	}

	protected IToken consumeArrayModifiers(IDeclarator d, IASTScope scope)
			throws EndOfFileException, BacktrackException {
		int startingOffset = LA(1).getOffset();
		IToken last = null;
		while (LT(1) == IToken.tLBRACKET) {
			consume(IToken.tLBRACKET); // eat the '['

			IASTExpression exp = null;
			if (LT(1) != IToken.tRBRACKET) {
				exp = constantExpression(scope,
						CompletionKind.SINGLE_NAME_REFERENCE,
						KeywordSetKey.EXPRESSION);
			}
			last = consume(IToken.tRBRACKET);
			IASTArrayModifier arrayMod = null;
			try {
				arrayMod = astFactory.createArrayModifier(exp);
			} catch (Exception e) {
				logException("consumeArrayModifiers::createArrayModifier()", e); //$NON-NLS-1$
				throwBacktrack(startingOffset, last.getEndOffset(), last.getLineNumber());
			}
			d.addArrayModifier(arrayMod);
		}
		return last;
	}

	protected void operatorId(Declarator d, IToken originalToken,
			TemplateParameterManager templateArgs,
			IASTCompletionNode.CompletionKind completionKind)
			throws BacktrackException, EndOfFileException {
		// we know this is an operator
		IToken operatorToken = consume(IToken.t_operator);
		IToken toSend = null;
		if (LA(1).isOperator() || LT(1) == IToken.tLPAREN
				|| LT(1) == IToken.tLBRACKET) {
			if ((LT(1) == IToken.t_new || LT(1) == IToken.t_delete)
					&& LT(2) == IToken.tLBRACKET && LT(3) == IToken.tRBRACKET) {
				consume();
				consume(IToken.tLBRACKET);
				toSend = consume(IToken.tRBRACKET);
				// vector new and delete operators
			} else if (LT(1) == IToken.tLPAREN && LT(2) == IToken.tRPAREN) {
				// operator ()
				consume(IToken.tLPAREN);
				toSend = consume(IToken.tRPAREN);
			} else if (LT(1) == IToken.tLBRACKET && LT(2) == IToken.tRBRACKET) {
				consume(IToken.tLBRACKET);
				toSend = consume(IToken.tRBRACKET);
			} else if (LA(1).isOperator())
				toSend = consume();
			else
				throwBacktrack(operatorToken.getOffset(), toSend != null ? toSend.getEndOffset() : 0, operatorToken.getLineNumber() );
		} else {
			// must be a conversion function
			typeId(d.getDeclarationWrapper().getScope(), true,
					CompletionKind.TYPE_REFERENCE);
			toSend = lastToken;
		}

		boolean hasTemplateId = (templateArgs != null);
		boolean grabbedNewInstance = false;
		if (templateArgs == null) {
			templateArgs = TemplateParameterManager.getInstance();
			grabbedNewInstance = true;
		}

		try {
			toSend = consumeTemplateArguments(d.getDeclarationWrapper()
					.getScope(), toSend, templateArgs, completionKind);
			if (toSend.getType() == IToken.tGT) {
				hasTemplateId = true;
			}

			ITokenDuple duple = TokenFactory.createTokenDuple(
					originalToken == null ? operatorToken : originalToken,
					toSend, (hasTemplateId ? templateArgs
							.getTemplateArgumentsList() : null));

			d.setName(duple);
		} finally {
			if (grabbedNewInstance)
				TemplateParameterManager.returnInstance(templateArgs);
		}
	}

	/**
	 * Parse a Pointer Operator.   
	 * 
	 * ptrOperator
	 * : "*" (cvQualifier)*
	 * | "&"
	 * | ::? nestedNameSpecifier "*" (cvQualifier)*
	 * 
	 * @param owner 		Declarator that this pointer operator corresponds to.  
	 * @throws BacktrackException 	request a backtrack
	 */
	protected IToken consumePointerOperators(IDeclarator d)
			throws EndOfFileException, BacktrackException {
		IToken result = null;
		for (;;) {
			if (LT(1) == IToken.tAMPER) {
				result = consume(IToken.tAMPER);
				d.addPointerOperator(ASTPointerOperator.REFERENCE);
				return result;

			}
			IToken mark = mark();

			ITokenDuple nameDuple = null;
			if (LT(1) == IToken.tIDENTIFIER || LT(1) == IToken.tCOLONCOLON) {
				try {
					try {
						nameDuple = name(d.getScope(),
								CompletionKind.SINGLE_NAME_REFERENCE,
								KeywordSetKey.EMPTY);
					} catch (OffsetLimitReachedException olre) {
						backup(mark);
						return null;
					}
				} catch (BacktrackException bt) {
					backup(mark);
					return null;
				}
			}
			if (LT(1) == IToken.tSTAR) {
				result = consume(IToken.tSTAR);

				d.setPointerOperatorName(nameDuple);

				IToken successful = null;
				for (;;) {
					IToken newSuccess = cvQualifier(d);
					if (newSuccess != null)
						successful = newSuccess;
					else
						break;

				}

				if (successful == null) {
					d.addPointerOperator(ASTPointerOperator.POINTER);
				}
				continue;
			}
			if (nameDuple != null)
				nameDuple.freeReferences(astFactory.getReferenceManager());
			backup(mark);
			return result;
		}
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression constantExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws BacktrackException,
			EndOfFileException {
		return conditionalExpression(scope, kind, key);
	}

	public IASTExpression expression(IASTScope scope, CompletionKind kind,
			KeywordSetKey key) throws BacktrackException, EndOfFileException {
		IToken la = LA(1);
		int startingOffset = la.getOffset();
		int ln = la.getLineNumber();
		IASTExpression assignmentExpression = assignmentExpression(scope, kind,
				key);
		while (LT(1) == IToken.tCOMMA) {
			consume(IToken.tCOMMA);
			setParameterListExpression(assignmentExpression);
			IASTExpression secondExpression = assignmentExpression(scope, kind,
					key);
			setParameterListExpression(null);
			int endOffset = lastToken != null ? lastToken.getEndOffset() : 0 ;
			try {
				assignmentExpression = astFactory.createExpression(scope,
						IASTExpression.Kind.EXPRESSIONLIST,
						assignmentExpression, secondExpression, null, null,
						null, EMPTY_STRING, null);
			} catch (ASTSemanticException e) {
				throwBacktrack(e.getProblem());
			} catch (Exception e) {
				logException("expression::createExpression()", e); //$NON-NLS-1$
				throwBacktrack(startingOffset, endOffset, ln);
			}
		}
		return assignmentExpression;
	}

	/**
	 * @param assignmentExpression
	 */
	protected void setParameterListExpression(
			IASTExpression assignmentExpression) {
	}
	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression assignmentExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws EndOfFileException,
			BacktrackException {
		setCompletionValues(scope, kind, key);
		if (LT(1) == IToken.t_throw) {
			return throwExpression(scope, key);
		}
		IASTExpression conditionalExpression = conditionalExpression(scope,
				kind, key);
		// if the condition not taken, try assignment operators
		if (conditionalExpression != null
				&& conditionalExpression.getExpressionKind() == IASTExpression.Kind.CONDITIONALEXPRESSION)
			return conditionalExpression;
		switch (LT(1)) {
			case IToken.tASSIGN :
				return assignmentOperatorExpression(scope,
						IASTExpression.Kind.ASSIGNMENTEXPRESSION_NORMAL,
						conditionalExpression, kind, key);
			case IToken.tSTARASSIGN :
				return assignmentOperatorExpression(scope,
						IASTExpression.Kind.ASSIGNMENTEXPRESSION_MULT,
						conditionalExpression, kind, key);
			case IToken.tDIVASSIGN :
				return assignmentOperatorExpression(scope,
						IASTExpression.Kind.ASSIGNMENTEXPRESSION_DIV,
						conditionalExpression, kind, key);
			case IToken.tMODASSIGN :
				return assignmentOperatorExpression(scope,
						IASTExpression.Kind.ASSIGNMENTEXPRESSION_MOD,
						conditionalExpression, kind, key);
			case IToken.tPLUSASSIGN :
				return assignmentOperatorExpression(scope,
						IASTExpression.Kind.ASSIGNMENTEXPRESSION_PLUS,
						conditionalExpression, kind, key);
			case IToken.tMINUSASSIGN :
				return assignmentOperatorExpression(scope,
						IASTExpression.Kind.ASSIGNMENTEXPRESSION_MINUS,
						conditionalExpression, kind, key);
			case IToken.tSHIFTRASSIGN :
				return assignmentOperatorExpression(scope,
						IASTExpression.Kind.ASSIGNMENTEXPRESSION_RSHIFT,
						conditionalExpression, kind, key);
			case IToken.tSHIFTLASSIGN :
				return assignmentOperatorExpression(scope,
						IASTExpression.Kind.ASSIGNMENTEXPRESSION_LSHIFT,
						conditionalExpression, kind, key);
			case IToken.tAMPERASSIGN :
				return assignmentOperatorExpression(scope,
						IASTExpression.Kind.ASSIGNMENTEXPRESSION_AND,
						conditionalExpression, kind, key);
			case IToken.tXORASSIGN :
				return assignmentOperatorExpression(scope,
						IASTExpression.Kind.ASSIGNMENTEXPRESSION_XOR,
						conditionalExpression, kind, key);
			case IToken.tBITORASSIGN :
				return assignmentOperatorExpression(scope,
						IASTExpression.Kind.ASSIGNMENTEXPRESSION_OR,
						conditionalExpression, kind, key);
		}
		return conditionalExpression;
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression throwExpression(IASTScope scope, KeywordSetKey key)
			throws EndOfFileException, BacktrackException {
		IToken throwToken = consume(IToken.t_throw);
		setCompletionValues(scope, CompletionKind.SINGLE_NAME_REFERENCE,
				KeywordSetKey.EXPRESSION);
		IASTExpression throwExpression = null;
		try {
			throwExpression = expression(scope,
					CompletionKind.SINGLE_NAME_REFERENCE, key);
		} catch (BacktrackException b) {
		}
		int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
		try {
			return astFactory.createExpression(scope,
					IASTExpression.Kind.THROWEXPRESSION, throwExpression, null,
					null, null, null, EMPTY_STRING, null);
		} catch (ASTSemanticException e) {
			throwBacktrack(e.getProblem());
		} catch (Exception e) {
			logException("throwExpression::createExpression()", e); //$NON-NLS-1$
			throwBacktrack(throwToken.getOffset(), endOffset, throwToken.getLineNumber() );

		}
		return null;
	}

	/**
	 * @param expression
	 * @return
	 * @throws BacktrackException
	 */
	protected IASTExpression conditionalExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws BacktrackException,
			EndOfFileException {
		IToken la = LA(1);
		int startingOffset = la.getOffset();
		int ln = la.getLineNumber();
		la = null;
		IASTExpression firstExpression = logicalOrExpression(scope, kind, key);
		if (LT(1) == IToken.tQUESTION) {
			consume(IToken.tQUESTION);
			IASTExpression secondExpression = expression(scope, kind, key);
			consume(IToken.tCOLON);
			IASTExpression thirdExpression = assignmentExpression(scope, kind,
					key);
			int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
			try {
				return astFactory.createExpression(scope,
						IASTExpression.Kind.CONDITIONALEXPRESSION,
						firstExpression, secondExpression, thirdExpression,
						null, null, EMPTY_STRING, null);
			} catch (ASTSemanticException e) {
				throwBacktrack(e.getProblem());
			} catch (Exception e) {
				logException("conditionalExpression::createExpression()", e); //$NON-NLS-1$
				throwBacktrack(startingOffset, endOffset, ln);
			}
		}
		return firstExpression;
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression logicalOrExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws BacktrackException,
			EndOfFileException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression firstExpression = logicalAndExpression(scope, kind, key);
		while (LT(1) == IToken.tOR) {
			consume(IToken.tOR);
			IASTExpression secondExpression = logicalAndExpression(scope, kind,
					key);
			int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
			try {
				firstExpression = astFactory.createExpression(scope,
						IASTExpression.Kind.LOGICALOREXPRESSION,
						firstExpression, secondExpression, null, null, null,
						EMPTY_STRING, null);
			} catch (ASTSemanticException e) {
				throwBacktrack(e.getProblem());
			} catch (Exception e) {
				logException("logicalOrExpression::createExpression()", e); //$NON-NLS-1$
				throwBacktrack(startingOffset, endOffset, line);
			}
		}
		return firstExpression;
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression logicalAndExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws BacktrackException,
			EndOfFileException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression firstExpression = inclusiveOrExpression(scope, kind, key);
		while (LT(1) == IToken.tAND) {
			consume(IToken.tAND);
			IASTExpression secondExpression = inclusiveOrExpression(scope,
					kind, key);
			int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
			try {
				firstExpression = astFactory.createExpression(scope,
						IASTExpression.Kind.LOGICALANDEXPRESSION,
						firstExpression, secondExpression, null, null, null,
						EMPTY_STRING, null);
			} catch (ASTSemanticException e) {
				throwBacktrack(e.getProblem());
			} catch (Exception e) {
				logException("logicalAndExpression::createExpression()", e); //$NON-NLS-1$
				throwBacktrack(startingOffset, endOffset, line);
			}
		}
		return firstExpression;
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression inclusiveOrExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws BacktrackException,
			EndOfFileException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression firstExpression = exclusiveOrExpression(scope, kind, key);
		while (LT(1) == IToken.tBITOR) {
			consume();
			IASTExpression secondExpression = exclusiveOrExpression(scope,
					kind, key);
			int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
			try {
				firstExpression = astFactory.createExpression(scope,
						IASTExpression.Kind.INCLUSIVEOREXPRESSION,
						firstExpression, secondExpression, null, null, null,
						EMPTY_STRING, null);
			} catch (ASTSemanticException e) {
				throwBacktrack(e.getProblem());
			} catch (Exception e) {
				logException("inclusiveOrExpression::createExpression()", e); //$NON-NLS-1$
				throwBacktrack(startingOffset, endOffset, line);
			}
		}
		return firstExpression;
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression exclusiveOrExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws BacktrackException,
			EndOfFileException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression firstExpression = andExpression(scope, kind, key);
		while (LT(1) == IToken.tXOR) {
			consume();

			IASTExpression secondExpression = andExpression(scope, kind, key);
			int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
			try {
				firstExpression = astFactory.createExpression(scope,
						IASTExpression.Kind.EXCLUSIVEOREXPRESSION,
						firstExpression, secondExpression, null, null, null,
						EMPTY_STRING, null);
			} catch (ASTSemanticException e) {
				throwBacktrack(e.getProblem());
			} catch (Exception e) {
				logException("exclusiveORExpression::createExpression()", e); //$NON-NLS-1$
				throwBacktrack(startingOffset, endOffset, line);
			}
		}
		return firstExpression;
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression andExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws EndOfFileException,
			BacktrackException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression firstExpression = equalityExpression(scope, kind, key);
		while (LT(1) == IToken.tAMPER) {
			consume();
			IASTExpression secondExpression = equalityExpression(scope, kind,
					key);
			int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
			try {
				firstExpression = astFactory.createExpression(scope,
						IASTExpression.Kind.ANDEXPRESSION, firstExpression,
						secondExpression, null, null, null, EMPTY_STRING, null);
			} catch (ASTSemanticException e) {
				throwBacktrack(e.getProblem());
			} catch (Exception e) {
				logException("andExpression::createExpression()", e); //$NON-NLS-1$
				throwBacktrack(startingOffset, endOffset, line);
			}
		}
		return firstExpression;
	}

	/**
	 * @param methodName
	 * @param e
	 */
	public void logException(String methodName, Exception e) {
		if (!(e instanceof EndOfFileException) && e != null && log.isTracing()) {
			StringBuffer buffer = new StringBuffer();
			buffer.append("Parser: Unexpected exception in "); //$NON-NLS-1$
			buffer.append(methodName);
			buffer.append(":"); //$NON-NLS-1$
			buffer.append(e.getClass().getName());
			buffer.append("::"); //$NON-NLS-1$
			buffer.append(e.getMessage());
			buffer.append(". w/"); //$NON-NLS-1$
			buffer.append(scanner.toString());
			log.traceLog(buffer.toString());
//			log.errorLog(buffer.toString());
		}
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression equalityExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws EndOfFileException,
			BacktrackException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression firstExpression = relationalExpression(scope, kind, key);
		for (;;) {
			switch (LT(1)) {
				case IToken.tEQUAL :
				case IToken.tNOTEQUAL :
					IToken t = consume();
					IASTExpression secondExpression = relationalExpression(
							scope, kind, key);
					int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
					try {
						firstExpression = astFactory.createExpression(scope, (t
								.getType() == IToken.tEQUAL)
								? IASTExpression.Kind.EQUALITY_EQUALS
								: IASTExpression.Kind.EQUALITY_NOTEQUALS,
								firstExpression, secondExpression, null, null,
								null, EMPTY_STRING, null);
					} catch (ASTSemanticException e) {
						throwBacktrack(e.getProblem());
					} catch (Exception e) {
						logException(
								"equalityExpression::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
					break;
				default :
					return firstExpression;
			}
		}
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression relationalExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws BacktrackException,
			EndOfFileException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression firstExpression = shiftExpression(scope, kind, key);
		for (;;) {
			switch (LT(1)) {
				case IToken.tGT :
					if (templateIdScopes != null
							&& ((Integer) templateIdScopes.peek()).intValue() == IToken.tLT) {
						return firstExpression;
					}
				case IToken.tLT :
				case IToken.tLTEQUAL :
				case IToken.tGTEQUAL :
					IToken mark = mark();
					int t = consume().getType();
					IASTExpression secondExpression = shiftExpression(scope,
							kind, key);
					if (LA(1) == mark.getNext()) {
						// we did not consume anything
						// this is most likely an error
						backup(mark);
						return firstExpression;
					}
					IASTExpression.Kind expressionKind = null;
					switch (t) {
						case IToken.tGT :
							expressionKind = IASTExpression.Kind.RELATIONAL_GREATERTHAN;
							break;
						case IToken.tLT :
							expressionKind = IASTExpression.Kind.RELATIONAL_LESSTHAN;
							break;
						case IToken.tLTEQUAL :
							expressionKind = IASTExpression.Kind.RELATIONAL_LESSTHANEQUALTO;
							break;
						case IToken.tGTEQUAL :
							expressionKind = IASTExpression.Kind.RELATIONAL_GREATERTHANEQUALTO;
							break;
					}
					int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
					try {
						firstExpression = astFactory.createExpression(scope,
								expressionKind, firstExpression,
								secondExpression, null, null, null,
								EMPTY_STRING, null);
					} catch (ASTSemanticException e) {
						throwBacktrack(e.getProblem());
					} catch (Exception e) {
						logException(
								"relationalExpression::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
					break;
				default :
					if (extension.isValidRelationalExpressionStart(language,
							LT(1))) {
						IASTExpression extensionExpression = extension
								.parseRelationalExpression(scope, this, kind,
										key, firstExpression);
						if (extensionExpression != null)
							return extensionExpression;
					}
					return firstExpression;
			}
		}
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	public IASTExpression shiftExpression(IASTScope scope, CompletionKind kind,
			KeywordSetKey key) throws BacktrackException, EndOfFileException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression firstExpression = additiveExpression(scope, kind, key);
		for (;;) {
			switch (LT(1)) {
				case IToken.tSHIFTL :
				case IToken.tSHIFTR :
					IToken t = consume();
					IASTExpression secondExpression = additiveExpression(scope,
							kind, key);
					int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
					try {
						firstExpression = astFactory.createExpression(scope,
								((t.getType() == IToken.tSHIFTL)
										? IASTExpression.Kind.SHIFT_LEFT
										: IASTExpression.Kind.SHIFT_RIGHT),
								firstExpression, secondExpression, null, null,
								null, EMPTY_STRING, null);
					} catch (ASTSemanticException e) {
						throwBacktrack(e.getProblem());
					} catch (Exception e) {
						logException("shiftExpression::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
					break;
				default :
					return firstExpression;
			}
		}
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression additiveExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws BacktrackException,
			EndOfFileException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression firstExpression = multiplicativeExpression(scope, kind,
				key);
		for (;;) {
			switch (LT(1)) {
				case IToken.tPLUS :
				case IToken.tMINUS :
					IToken t = consume();
					IASTExpression secondExpression = multiplicativeExpression(
							scope, kind, key);
					int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
					try {
						firstExpression = astFactory.createExpression(scope,
								((t.getType() == IToken.tPLUS)
										? IASTExpression.Kind.ADDITIVE_PLUS
										: IASTExpression.Kind.ADDITIVE_MINUS),
								firstExpression, secondExpression, null, null,
								null, EMPTY_STRING, null);
					} catch (ASTSemanticException e) {
						throwBacktrack(e.getProblem());
					} catch (Exception e) {
						logException(
								"additiveExpression::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
					break;
				default :
					return firstExpression;
			}
		}
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression multiplicativeExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws BacktrackException,
			EndOfFileException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression firstExpression = pmExpression(scope, kind, key);
		for (;;) {
			switch (LT(1)) {
				case IToken.tSTAR :
				case IToken.tDIV :
				case IToken.tMOD :
					IToken t = consume();
					IASTExpression secondExpression = pmExpression(scope, kind,
							key);
					IASTExpression.Kind expressionKind = null;
					switch (t.getType()) {
						case IToken.tSTAR :
							expressionKind = IASTExpression.Kind.MULTIPLICATIVE_MULTIPLY;
							break;
						case IToken.tDIV :
							expressionKind = IASTExpression.Kind.MULTIPLICATIVE_DIVIDE;
							break;
						case IToken.tMOD :
							expressionKind = IASTExpression.Kind.MULTIPLICATIVE_MODULUS;
							break;
					}
					int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
					try {
						firstExpression = astFactory.createExpression(scope,
								expressionKind, firstExpression,
								secondExpression, null, null, null,
								EMPTY_STRING, null);
					} catch (ASTSemanticException e) {
						firstExpression.freeReferences(astFactory
								.getReferenceManager());
						throwBacktrack(e.getProblem());
					} catch (Exception e) {
						logException(
								"multiplicativeExpression::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
					break;
				default :
					return firstExpression;
			}
		}
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression pmExpression(IASTScope scope, CompletionKind kind,
			KeywordSetKey key) throws EndOfFileException, BacktrackException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression firstExpression = castExpression(scope, kind, key);
		for (;;) {
			switch (LT(1)) {
				case IToken.tDOTSTAR :
				case IToken.tARROWSTAR :
					IToken t = consume();
					IASTExpression secondExpression = castExpression(scope,
							kind, key);
					int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
					try {
						firstExpression = astFactory.createExpression(scope,
								((t.getType() == IToken.tDOTSTAR)
										? IASTExpression.Kind.PM_DOTSTAR
										: IASTExpression.Kind.PM_ARROWSTAR),
								firstExpression, secondExpression, null, null,
								null, EMPTY_STRING, null);
					} catch (ASTSemanticException e) {
						throwBacktrack(e.getProblem());
					} catch (Exception e) {
						logException("pmExpression::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
					break;
				default :
					return firstExpression;
			}
		}
	}

	/**
	 * castExpression
	 * : unaryExpression
	 * | "(" typeId ")" castExpression
	 */
	protected IASTExpression castExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws EndOfFileException,
			BacktrackException {
		// TO DO: we need proper symbol checkint to ensure type name
		if (LT(1) == IToken.tLPAREN) {
			int startingOffset = LA(1).getOffset();
			int line = LA(1).getLineNumber();
			IToken mark = mark();
			consume();
			if (templateIdScopes != null) {
				templateIdScopes.push(new Integer(IToken.tLPAREN));
			}
			boolean popped = false;
			IASTTypeId typeId = null;
			// If this isn't a type name, then we shouldn't be here
			try {
				try {
					typeId = typeId(scope, false, getCastExpressionKind(kind));
					consume(IToken.tRPAREN);
				} catch (BacktrackException bte) {
					backup(mark);
					if (typeId != null)
						typeId.freeReferences(astFactory.getReferenceManager());
					throw bte;
				}
				
				if (templateIdScopes != null) {
					templateIdScopes.pop();
					popped = true;
				}
				IASTExpression castExpression = castExpression(scope, kind, key);
				if( castExpression != null && castExpression.getExpressionKind() == IASTExpression.Kind.PRIMARY_EMPTY )
				{
					backup( mark );
					if (typeId != null)
						typeId.freeReferences(astFactory.getReferenceManager());
					return unaryExpression(scope, kind, key);
				}
				int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
				mark = null; // clean up mark so that we can garbage collect
				try {
					return astFactory.createExpression(scope,
							IASTExpression.Kind.CASTEXPRESSION, castExpression,
							null, null, typeId, null, EMPTY_STRING, null);
				} catch (ASTSemanticException e) {
					throwBacktrack(e.getProblem());
				} catch (Exception e) {
					logException("castExpression::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(startingOffset, endOffset, line);
				}
			} catch (BacktrackException b) {
				if (templateIdScopes != null && !popped) {
					templateIdScopes.pop();
				}
			}
		}
		return unaryExpression(scope, kind, key);

	}

	/**
	 * @param kind
	 * @return
	 */
	private CompletionKind getCastExpressionKind(CompletionKind kind) {
		return ((kind == CompletionKind.SINGLE_NAME_REFERENCE || kind == CompletionKind.FUNCTION_REFERENCE)
				? kind
				: CompletionKind.TYPE_REFERENCE);
	}

	/**
	 * @param completionKind TODO
	 * @throws BacktrackException
	 */
	public IASTTypeId typeId(IASTScope scope, boolean skipArrayModifiers,
			CompletionKind completionKind) throws EndOfFileException,
			BacktrackException {
		IToken mark = mark();
		ITokenDuple name = null;
		boolean isConst = false, isVolatile = false;
		boolean isSigned = false, isUnsigned = false;
		boolean isShort = false, isLong = false;
		boolean isTypename = false;

		IASTSimpleTypeSpecifier.Type kind = null;
		do {
			try {
				name = name(scope, completionKind,
						KeywordSetKey.DECL_SPECIFIER_SEQUENCE);
				kind = IASTSimpleTypeSpecifier.Type.CLASS_OR_TYPENAME;
				break;
			} catch (BacktrackException b) {
				// do nothing
			}

			boolean encounteredType = false;
			simpleMods : for (;;) {
				switch (LT(1)) {
					case IToken.t_signed :
						consume();
						isSigned = true;
						break;

					case IToken.t_unsigned :
						consume();
						isUnsigned = true;
						break;

					case IToken.t_short :
						consume();
						isShort = true;
						break;

					case IToken.t_long :
						consume();
						isLong = true;
						break;

					case IToken.t_const :
						consume();
						isConst = true;
						break;

					case IToken.t_volatile :
						consume();
						isVolatile = true;
						break;

					case IToken.tIDENTIFIER :
						if (encounteredType)
							break simpleMods;
						encounteredType = true;
						name = name(scope, completionKind, KeywordSetKey.EMPTY);
						kind = IASTSimpleTypeSpecifier.Type.CLASS_OR_TYPENAME;
						break;

					case IToken.t_int :
						if (encounteredType)
							break simpleMods;
						encounteredType = true;
						kind = IASTSimpleTypeSpecifier.Type.INT;
						consume();
						break;

					case IToken.t_char :
						if (encounteredType)
							break simpleMods;
						encounteredType = true;
						kind = IASTSimpleTypeSpecifier.Type.CHAR;
						consume();
						break;

					case IToken.t_bool :
						if (encounteredType)
							break simpleMods;
						encounteredType = true;
						kind = IASTSimpleTypeSpecifier.Type.BOOL;
						consume();
						break;

					case IToken.t_double :
						if (encounteredType)
							break simpleMods;
						encounteredType = true;
						kind = IASTSimpleTypeSpecifier.Type.DOUBLE;
						consume();
						break;

					case IToken.t_float :
						if (encounteredType)
							break simpleMods;
						encounteredType = true;
						kind = IASTSimpleTypeSpecifier.Type.FLOAT;
						consume();
						break;

					case IToken.t_wchar_t :
						if (encounteredType)
							break simpleMods;
						encounteredType = true;
						kind = IASTSimpleTypeSpecifier.Type.WCHAR_T;
						consume();
						break;

					case IToken.t_void :
						if (encounteredType)
							break simpleMods;
						encounteredType = true;
						kind = IASTSimpleTypeSpecifier.Type.VOID;
						consume();
						break;

					case IToken.t__Bool :
						if (encounteredType)
							break simpleMods;
						encounteredType = true;
						kind = IASTSimpleTypeSpecifier.Type._BOOL;
						consume();
						break;

					default :
						break simpleMods;
				}
			}

			if (kind != null)
				break;

			if (isShort || isLong || isUnsigned || isSigned) {
				kind = IASTSimpleTypeSpecifier.Type.INT;
				break;
			}

			if (LT(1) == IToken.t_typename || LT(1) == IToken.t_struct
					|| LT(1) == IToken.t_class || LT(1) == IToken.t_enum
					|| LT(1) == IToken.t_union) {
				consume();
				try {
					name = name(scope, completionKind, KeywordSetKey.EMPTY);
					kind = IASTSimpleTypeSpecifier.Type.CLASS_OR_TYPENAME;
				} catch (BacktrackException b) {
					backup(mark);
					throwBacktrack(b);
				}
			}

		} while (false);

		int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
		if (kind == null)
			throwBacktrack(mark.getOffset(), endOffset, mark.getLineNumber());

		TypeId id = getTypeIdInstance(scope);
		IToken last = lastToken;
		IToken temp = last;

		//template parameters are consumed as part of name
		//lastToken = consumeTemplateParameters( last );
		//if( lastToken == null ) lastToken = last;

		temp = consumePointerOperators(id);
		if (temp != null)
			last = temp;

		if (!skipArrayModifiers) {
			temp = consumeArrayModifiers(id, scope);
			if (temp != null)
				last = temp;
		}

		endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
		try {
			String signature = "";//$NON-NLS-1$
			if (last != null)
			{
				if( lastToken == null )
					lastToken = last;
				signature = TokenFactory.createStringRepresentation(mark,
						last);
			}
			return astFactory.createTypeId(scope, kind, isConst, isVolatile,
					isShort, isLong, isSigned, isUnsigned, isTypename, name, id
							.getPointerOperators(), id.getArrayModifiers(),
					signature);
		} catch (ASTSemanticException e) {
			backup(mark);
			throwBacktrack(e.getProblem());
		} catch (Exception e) {
			logException("typeId::createTypeId()", e); //$NON-NLS-1$
			throwBacktrack(mark.getOffset(), endOffset, mark.getLineNumber());
		}
		return null;
	}

	/**
	 * @param scope
	 * @return
	 */
	private TypeId getTypeIdInstance(IASTScope scope) {
		typeIdInstance.reset(scope);
		return typeIdInstance;
	}
	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression deleteExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws EndOfFileException,
			BacktrackException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		if (LT(1) == IToken.tCOLONCOLON) {
			// global scope
			consume(IToken.tCOLONCOLON);
		}

		consume(IToken.t_delete);

		boolean vectored = false;
		if (LT(1) == IToken.tLBRACKET) {
			// array delete
			consume();
			consume(IToken.tRBRACKET);
			vectored = true;
		}
		IASTExpression castExpression = castExpression(scope, kind, key);
		int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
		try {
			return astFactory.createExpression(scope, (vectored
					? IASTExpression.Kind.DELETE_VECTORCASTEXPRESSION
					: IASTExpression.Kind.DELETE_CASTEXPRESSION),
					castExpression, null, null, null, null, EMPTY_STRING, null);
		} catch (ASTSemanticException e) {
			throwBacktrack(e.getProblem());
		} catch (Exception e) {
			logException("deleteExpression::createExpression()", e); //$NON-NLS-1$
			throwBacktrack(startingOffset, endOffset, line);
		}
		return null;
	}

	/**
	 * Pazse a new-expression.  
	 * 
	 * @param expression
	 * @throws BacktrackException
	 * 
	 * 
	 * newexpression: 	::? new newplacement? newtypeid newinitializer?
	 *					::? new newplacement? ( typeid ) newinitializer?
	 * newplacement:	( expressionlist )
	 * newtypeid:		typespecifierseq newdeclarator?
	 * newdeclarator:	ptroperator newdeclarator? | directnewdeclarator
	 * directnewdeclarator:		[ expression ]
	 *							directnewdeclarator [ constantexpression ]
	 * newinitializer:	( expressionlist? )
	 */
	protected IASTExpression newExpression(IASTScope scope, KeywordSetKey key)
			throws BacktrackException, EndOfFileException {
		setCompletionValues(scope, CompletionKind.NEW_TYPE_REFERENCE,
				KeywordSetKey.EMPTY);
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		if (LT(1) == IToken.tCOLONCOLON) {
			// global scope
			consume(IToken.tCOLONCOLON);
		}
		consume(IToken.t_new);
		boolean typeIdInParen = false;
		boolean placementParseFailure = true;
		IToken beforeSecondParen = null;
		IToken backtrackMarker = null;
		IASTTypeId typeId = null;
		ArrayList newPlacementExpressions = new ArrayList();
		ArrayList newTypeIdExpressions = new ArrayList();
		ArrayList newInitializerExpressions = new ArrayList();

		if (LT(1) == IToken.tLPAREN) {
			consume(IToken.tLPAREN);
			if (templateIdScopes != null) {
				templateIdScopes.push(new Integer(IToken.tLPAREN));
			}
			try {
				// Try to consume placement list
				// Note: since expressionList and expression are the same...
				backtrackMarker = mark();
				newPlacementExpressions.add(expression(scope,
						CompletionKind.SINGLE_NAME_REFERENCE, key));
				consume(IToken.tRPAREN);
				if (templateIdScopes != null) {
					templateIdScopes.pop();
				} //pop 1st Parent
				placementParseFailure = false;
				if (LT(1) == IToken.tLPAREN) {
					beforeSecondParen = mark();
					consume(IToken.tLPAREN);
					if (templateIdScopes != null) {
						templateIdScopes.push(new Integer(IToken.tLPAREN));
					} //push 2nd Paren
					typeIdInParen = true;
				}
			} catch (BacktrackException e) {
				backup(backtrackMarker);
			}
			if (placementParseFailure) {
				// CASE: new (typeid-not-looking-as-placement) ...
				// the first expression in () is not a placement
				// - then it has to be typeId
				typeId = typeId(scope, true, CompletionKind.NEW_TYPE_REFERENCE);
				consume(IToken.tRPAREN);
				if (templateIdScopes != null) {
					templateIdScopes.pop();
				} //pop 1st Paren
			} else {
				if (!typeIdInParen) {
					if (LT(1) == IToken.tLBRACKET) {
						// CASE: new (typeid-looking-as-placement) [expr]...
						// the first expression in () has been parsed as a placement;
						// however, we assume that it was in fact typeId, and this 
						// new statement creates an array.
						// Do nothing, fallback to array/initializer processing
					} else {
						// CASE: new (placement) typeid ...
						// the first expression in () is parsed as a placement,
						// and the next expression doesn't start with '(' or '['
						// - then it has to be typeId
						try {
							backtrackMarker = mark();
							typeId = typeId(scope, true,
									CompletionKind.NEW_TYPE_REFERENCE);
						} catch (BacktrackException e) {
							// Hmmm, so it wasn't typeId after all... Then it is
							// CASE: new (typeid-looking-as-placement)
							backup(backtrackMarker);
							// TODO fix this
							return null;
						}
					}
				} else {
					// Tricky cases: first expression in () is parsed as a placement,
					// and the next expression starts with '('.
					// The problem is, the first expression might as well be a typeid
					try {
						typeId = typeId(scope, true,
								CompletionKind.NEW_TYPE_REFERENCE);
						consume(IToken.tRPAREN);
						if (templateIdScopes != null) {
							templateIdScopes.pop();
						} //popping the 2nd Paren

						if (LT(1) == IToken.tLPAREN
								|| LT(1) == IToken.tLBRACKET) {
							// CASE: new (placement)(typeid)(initializer)
							// CASE: new (placement)(typeid)[] ...
							// Great, so far all our assumptions have been correct
							// Do nothing, fallback to array/initializer processing
						} else {
							// CASE: new (placement)(typeid)
							// CASE: new (typeid-looking-as-placement)(initializer-looking-as-typeid)
							// Worst-case scenario - this cannot be resolved w/o more semantic information.
							// Luckily, we don't need to know what was that - we only know that 
							// new-expression ends here.
							int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
							try {
								setCompletionValues(scope,
										CompletionKind.NO_SUCH_KIND,
										KeywordSetKey.EMPTY);
								return astFactory.createExpression(scope,
										IASTExpression.Kind.NEW_TYPEID, null,
										null, null, typeId, null, EMPTY_STRING,
										astFactory.createNewDescriptor(
												newPlacementExpressions,
												newTypeIdExpressions,
												newInitializerExpressions));
							} catch (ASTSemanticException e) {
								throwBacktrack(e.getProblem());
							} catch (Exception e) {
								logException(
										"newExpression_1::createExpression()", e); //$NON-NLS-1$
								throwBacktrack(startingOffset, endOffset, line);
							}
						}
					} catch (BacktrackException e) {
						// CASE: new (typeid-looking-as-placement)(initializer-not-looking-as-typeid)
						// Fallback to initializer processing
						backup(beforeSecondParen);
						if (templateIdScopes != null) {
							templateIdScopes.pop();
						}//pop that 2nd paren
					}
				}
			}
		} else {
			// CASE: new typeid ...
			// new parameters do not start with '('
			// i.e it has to be a plain typeId
			typeId = typeId(scope, true, CompletionKind.NEW_TYPE_REFERENCE);
		}
		while (LT(1) == IToken.tLBRACKET) {
			// array new
			consume();

			if (templateIdScopes != null) {
				templateIdScopes.push(new Integer(IToken.tLBRACKET));
			}

			newTypeIdExpressions.add(assignmentExpression(scope,
					CompletionKind.SINGLE_NAME_REFERENCE, key));
			consume(IToken.tRBRACKET);

			if (templateIdScopes != null) {
				templateIdScopes.pop();
			}
		}
		// newinitializer
		if (LT(1) == IToken.tLPAREN) {
			consume(IToken.tLPAREN);
			setCurrentFunctionName(((typeId != null) ? typeId
					.getFullSignature() : EMPTY_STRING));
			setCompletionValues(scope, CompletionKind.CONSTRUCTOR_REFERENCE);
			if (templateIdScopes != null) {
				templateIdScopes.push(new Integer(IToken.tLPAREN));
			}

			//we want to know the difference between no newInitializer and an empty new Initializer
			//if the next token is the RPAREN, then we have an Empty expression in our list.
			newInitializerExpressions.add(expression(scope,
					CompletionKind.CONSTRUCTOR_REFERENCE, key));

			setCurrentFunctionName(EMPTY_STRING);
			consume(IToken.tRPAREN);
			if (templateIdScopes != null) {
				templateIdScopes.pop();
			}
		}
		setCompletionValues(scope, CompletionKind.NO_SUCH_KIND,
				KeywordSetKey.EMPTY);
		int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
		try {
			return astFactory.createExpression(scope,
					IASTExpression.Kind.NEW_TYPEID, null, null, null, typeId,
					null, EMPTY_STRING, astFactory.createNewDescriptor(
							newPlacementExpressions, newTypeIdExpressions,
							newInitializerExpressions));
		} catch (ASTSemanticException e) {
			throwBacktrack(e.getProblem());
			return null;
		} catch (Exception e) {
			logException("newExpression_2::createExpression()", e); //$NON-NLS-1$
			throwBacktrack(startingOffset, endOffset, line);
		}
		return null;
	}

	/**
	 * @param functionName 
	 */
	protected void setCurrentFunctionName(String functionName) {
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	public IASTExpression unaryExpression(IASTScope scope, CompletionKind kind,
			KeywordSetKey key) throws EndOfFileException, BacktrackException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		switch (LT(1)) {
			case IToken.tSTAR :
				consume();
				return unaryOperatorCastExpression(scope,
						IASTExpression.Kind.UNARY_STAR_CASTEXPRESSION, kind,
						key);
			case IToken.tAMPER :
				consume();
				return unaryOperatorCastExpression(scope,
						IASTExpression.Kind.UNARY_AMPSND_CASTEXPRESSION, kind,
						key);
			case IToken.tPLUS :
				consume();
				return unaryOperatorCastExpression(scope,
						IASTExpression.Kind.UNARY_PLUS_CASTEXPRESSION, kind,
						key);
			case IToken.tMINUS :
				consume();
				return unaryOperatorCastExpression(scope,
						IASTExpression.Kind.UNARY_MINUS_CASTEXPRESSION, kind,
						key);
			case IToken.tNOT :
				consume();
				return unaryOperatorCastExpression(scope,
						IASTExpression.Kind.UNARY_NOT_CASTEXPRESSION, kind, key);
			case IToken.tCOMPL :
				consume();
				return unaryOperatorCastExpression(scope,
						IASTExpression.Kind.UNARY_TILDE_CASTEXPRESSION, kind,
						key);
			case IToken.tINCR :
				consume();
				return unaryOperatorCastExpression(scope,
						IASTExpression.Kind.UNARY_INCREMENT, kind, key);
			case IToken.tDECR :
				consume();
				return unaryOperatorCastExpression(scope,
						IASTExpression.Kind.UNARY_DECREMENT, kind, key);
			case IToken.t_sizeof :
				consume(IToken.t_sizeof);
				IToken mark = LA(1);
				IASTTypeId d = null;
				IASTExpression unaryExpression = null;
				if (LT(1) == IToken.tLPAREN) {
					try {
						consume(IToken.tLPAREN);
						d = typeId(scope, false,
								CompletionKind.SINGLE_NAME_REFERENCE);
						consume(IToken.tRPAREN);
					} catch (BacktrackException bt) {
						backup(mark);
						unaryExpression = unaryExpression(scope, kind, key);
					}
				} else {
					unaryExpression = unaryExpression(scope, kind, key);
				}
				int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
				if (unaryExpression == null)
					try {
						return astFactory.createExpression(scope,
								IASTExpression.Kind.UNARY_SIZEOF_TYPEID, null,
								null, null, d, null, EMPTY_STRING, null);
					} catch (ASTSemanticException e) {
						throwBacktrack(e.getProblem());
					} catch (Exception e) {
						logException("unaryExpression_1::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
				try {
					return astFactory.createExpression(scope,
							IASTExpression.Kind.UNARY_SIZEOF_UNARYEXPRESSION,
							unaryExpression, null, null, null, null,
							EMPTY_STRING, null);
				} catch (ASTSemanticException e1) {
					throwBacktrack(e1.getProblem());
				} catch (Exception e) {
					logException("unaryExpression_1::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(startingOffset, endOffset, line);
				}
			case IToken.t_new :
				return newExpression(scope, key);
			case IToken.t_delete :
				return deleteExpression(scope, kind, key);
			case IToken.tCOLONCOLON :
				if (queryLookaheadCapability(2)) {
					switch (LT(2)) {
						case IToken.t_new :
							return newExpression(scope, key);
						case IToken.t_delete :
							return deleteExpression(scope, kind, key);
						default :
							return postfixExpression(scope, kind, key);
					}
				}
			default :
				if (extension.isValidUnaryExpressionStart(LT(1))) {
					IASTExpression extensionExpression = extension
							.parseUnaryExpression(scope, this, kind, key);
					if (extensionExpression != null)
						return extensionExpression;
				}
				return postfixExpression(scope, kind, key);
		}
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression postfixExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws EndOfFileException,
			BacktrackException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression firstExpression = null;
		boolean isTemplate = false;

		setCompletionValues(scope, kind, key);
		switch (LT(1)) {
			case IToken.t_typename :
				consume(IToken.t_typename);

				boolean templateTokenConsumed = false;
				if (LT(1) == IToken.t_template) {
					consume(IToken.t_template);
					templateTokenConsumed = true;
				}
				ITokenDuple nestedName = name(scope,
						CompletionKind.TYPE_REFERENCE, KeywordSetKey.EMPTY);

				consume(IToken.tLPAREN);
				if (templateIdScopes != null) {
					templateIdScopes.push(new Integer(IToken.tLPAREN));
				}
				IASTExpression expressionList = expression(scope,
						CompletionKind.TYPE_REFERENCE, key);
				int endOffset = consume(IToken.tRPAREN).getEndOffset();
				if (templateIdScopes != null) {
					templateIdScopes.pop();
				}
				
				try {
					firstExpression = astFactory
							.createExpression(
									scope,
									(templateTokenConsumed
											? IASTExpression.Kind.POSTFIX_TYPENAME_TEMPLATEID
											: IASTExpression.Kind.POSTFIX_TYPENAME_IDENTIFIER),
									expressionList, null, null, null,
									nestedName, EMPTY_STRING, null);
				} catch (ASTSemanticException ase) {
					throwBacktrack(ase.getProblem());
				} catch (Exception e) {
					logException("postfixExpression_1::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(startingOffset, endOffset, line);
				}
				break;
			// simple-type-specifier ( assignment-expression , .. )
			case IToken.t_char :
				firstExpression = simpleTypeConstructorExpression(scope,
						IASTExpression.Kind.POSTFIX_SIMPLETYPE_CHAR, key);
				break;
			case IToken.t_wchar_t :
				firstExpression = simpleTypeConstructorExpression(scope,
						IASTExpression.Kind.POSTFIX_SIMPLETYPE_WCHART, key);
				break;
			case IToken.t_bool :
				firstExpression = simpleTypeConstructorExpression(scope,
						IASTExpression.Kind.POSTFIX_SIMPLETYPE_BOOL, key);
				break;
			case IToken.t_short :
				firstExpression = simpleTypeConstructorExpression(scope,
						IASTExpression.Kind.POSTFIX_SIMPLETYPE_SHORT, key);
				break;
			case IToken.t_int :
				firstExpression = simpleTypeConstructorExpression(scope,
						IASTExpression.Kind.POSTFIX_SIMPLETYPE_INT, key);
				break;
			case IToken.t_long :
				firstExpression = simpleTypeConstructorExpression(scope,
						IASTExpression.Kind.POSTFIX_SIMPLETYPE_LONG, key);
				break;
			case IToken.t_signed :
				firstExpression = simpleTypeConstructorExpression(scope,
						IASTExpression.Kind.POSTFIX_SIMPLETYPE_SIGNED, key);
				break;
			case IToken.t_unsigned :
				firstExpression = simpleTypeConstructorExpression(scope,
						IASTExpression.Kind.POSTFIX_SIMPLETYPE_UNSIGNED, key);
				break;
			case IToken.t_float :
				firstExpression = simpleTypeConstructorExpression(scope,
						IASTExpression.Kind.POSTFIX_SIMPLETYPE_FLOAT, key);
				break;
			case IToken.t_double :
				firstExpression = simpleTypeConstructorExpression(scope,
						IASTExpression.Kind.POSTFIX_SIMPLETYPE_DOUBLE, key);
				break;
			case IToken.t_dynamic_cast :
				firstExpression = specialCastExpression(scope,
						IASTExpression.Kind.POSTFIX_DYNAMIC_CAST, key);
				break;
			case IToken.t_static_cast :
				firstExpression = specialCastExpression(scope,
						IASTExpression.Kind.POSTFIX_STATIC_CAST, key);
				break;
			case IToken.t_reinterpret_cast :
				firstExpression = specialCastExpression(scope,
						IASTExpression.Kind.POSTFIX_REINTERPRET_CAST, key);
				break;
			case IToken.t_const_cast :
				firstExpression = specialCastExpression(scope,
						IASTExpression.Kind.POSTFIX_CONST_CAST, key);
				break;
			case IToken.t_typeid :
				consume();
				consume(IToken.tLPAREN);
				if (templateIdScopes != null) {
					templateIdScopes.push(new Integer(IToken.tLPAREN));
				}
				boolean isTypeId = true;
				IASTExpression lhs = null;
				IASTTypeId typeId = null;
				try {
					typeId = typeId(scope, false, CompletionKind.TYPE_REFERENCE);
				} catch (BacktrackException b) {
					isTypeId = false;
					lhs = expression(scope, CompletionKind.TYPE_REFERENCE, key);
				}
				endOffset = consume(IToken.tRPAREN).getEndOffset();
				if (templateIdScopes != null) {
					templateIdScopes.pop();
				}
				try {
					firstExpression = astFactory
							.createExpression(
									scope,
									(isTypeId
											? IASTExpression.Kind.POSTFIX_TYPEID_TYPEID
											: IASTExpression.Kind.POSTFIX_TYPEID_EXPRESSION),
									lhs, null, null, typeId, null,
									EMPTY_STRING, null);
				} catch (ASTSemanticException e6) {
					throwBacktrack(e6.getProblem());
				} catch (Exception e) {
					logException("postfixExpression_2::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(startingOffset, endOffset, line);
				}
				break;
			default :
				firstExpression = primaryExpression(scope, kind, key);
		}
		IASTExpression secondExpression = null;
		for (;;) {
			switch (LT(1)) {
				case IToken.tLBRACKET :
					// array access
					consume(IToken.tLBRACKET);
					if (templateIdScopes != null) {
						templateIdScopes.push(new Integer(IToken.tLBRACKET));
					}
					secondExpression = expression(scope,
							CompletionKind.SINGLE_NAME_REFERENCE, key);
					int endOffset = consume(IToken.tRBRACKET).getEndOffset();
					if (templateIdScopes != null) {
						templateIdScopes.pop();
					}
					try {
						firstExpression = astFactory.createExpression(scope,
								IASTExpression.Kind.POSTFIX_SUBSCRIPT,
								firstExpression, secondExpression, null, null,
								null, EMPTY_STRING, null);
					} catch (ASTSemanticException e2) {
						throwBacktrack(e2.getProblem());
					} catch (Exception e) {
						logException(
								"postfixExpression_3::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
					break;
				case IToken.tLPAREN :
					// function call
					consume(IToken.tLPAREN);
					IASTNode context = null;
					if (firstExpression != null) {
						if (firstExpression.getExpressionKind() == IASTExpression.Kind.ID_EXPRESSION)
							setCurrentFunctionName(firstExpression
									.getIdExpression());
						else if (firstExpression.getRHSExpression() != null
								&& firstExpression.getRHSExpression()
										.getIdExpression() != null) {
							setCurrentFunctionName(firstExpression
									.getRHSExpression().getIdExpression());
							context = astFactory
									.expressionToMostPreciseASTNode(scope,
											firstExpression.getLHSExpression());
						}
					}

					if (templateIdScopes != null) {
						templateIdScopes.push(new Integer(IToken.tLPAREN));
					}
					setCompletionValues(scope,
							CompletionKind.FUNCTION_REFERENCE, context);
					secondExpression = expression(scope,
							CompletionKind.FUNCTION_REFERENCE, key);
					setCurrentFunctionName(EMPTY_STRING);
					endOffset = consume(IToken.tRPAREN).getEndOffset();
					if (templateIdScopes != null) {
						templateIdScopes.pop();
					}
					try {
						firstExpression = astFactory.createExpression(scope,
								IASTExpression.Kind.POSTFIX_FUNCTIONCALL,
								firstExpression, secondExpression, null, null,
								null, EMPTY_STRING, null);
					} catch (ASTSemanticException e3) {
						throwBacktrack(e3.getProblem());
					} catch (Exception e) {
						logException(
								"postfixExpression_4::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
					break;
				case IToken.tINCR :
					endOffset = consume(IToken.tINCR).getEndOffset();
					try {
						firstExpression = astFactory.createExpression(scope,
								IASTExpression.Kind.POSTFIX_INCREMENT,
								firstExpression, null, null, null, null,
								EMPTY_STRING, null);
					} catch (ASTSemanticException e1) {
						throwBacktrack(e1.getProblem());
					} catch (Exception e) {
						logException(
								"postfixExpression_5::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
					break;
				case IToken.tDECR :
					endOffset = consume().getEndOffset();
					try {
						firstExpression = astFactory.createExpression(scope,
								IASTExpression.Kind.POSTFIX_DECREMENT,
								firstExpression, null, null, null, null,
								EMPTY_STRING, null);
					} catch (ASTSemanticException e4) {
						throwBacktrack(e4.getProblem());
					} catch (Exception e) {
						logException(
								"postfixExpression_6::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
					break;
				case IToken.tDOT :
					// member access
					consume(IToken.tDOT);

					if (queryLookaheadCapability())
						if (LT(1) == IToken.t_template) {
							consume(IToken.t_template);
							isTemplate = true;
						}

					Kind memberCompletionKind = (isTemplate
							? IASTExpression.Kind.POSTFIX_DOT_TEMPL_IDEXPRESS
							: IASTExpression.Kind.POSTFIX_DOT_IDEXPRESSION);

					setCompletionValues(scope, CompletionKind.MEMBER_REFERENCE,
							KeywordSetKey.EMPTY, firstExpression,
							memberCompletionKind);
					secondExpression = primaryExpression(scope,
							CompletionKind.MEMBER_REFERENCE, key);
					endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
					if (secondExpression != null
							&& secondExpression.getExpressionKind() == Kind.ID_EXPRESSION
							&& secondExpression.getIdExpression().indexOf('~') != -1)
						memberCompletionKind = Kind.POSTFIX_DOT_DESTRUCTOR;

					try {
						firstExpression = astFactory.createExpression(scope,
								memberCompletionKind, firstExpression,
								secondExpression, null, null, null,
								EMPTY_STRING, null);
					} catch (ASTSemanticException e5) {
						throwBacktrack(e5.getProblem());
					} catch (Exception e) {
						logException(
								"postfixExpression_7::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
					break;
				case IToken.tARROW :
					// member access
					consume(IToken.tARROW);

					if (queryLookaheadCapability())
						if (LT(1) == IToken.t_template) {
							consume(IToken.t_template);
							isTemplate = true;
						}

					Kind arrowCompletionKind = (isTemplate
							? IASTExpression.Kind.POSTFIX_ARROW_TEMPL_IDEXP
							: IASTExpression.Kind.POSTFIX_ARROW_IDEXPRESSION);

					setCompletionValues(scope, CompletionKind.MEMBER_REFERENCE,
							KeywordSetKey.EMPTY, firstExpression,
							arrowCompletionKind);
					secondExpression = primaryExpression(scope,
							CompletionKind.MEMBER_REFERENCE, key);
					endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
					if (secondExpression != null
							&& secondExpression.getExpressionKind() == Kind.ID_EXPRESSION
							&& secondExpression.getIdExpression().indexOf('~') != -1)
						arrowCompletionKind = Kind.POSTFIX_ARROW_DESTRUCTOR;
					try {
						firstExpression = astFactory.createExpression(scope,
								arrowCompletionKind, firstExpression,
								secondExpression, null, null, null,
								EMPTY_STRING, null);
					} catch (ASTSemanticException e) {
						throwBacktrack(e.getProblem());
					} catch (Exception e) {
						logException(
								"postfixExpression_8::createExpression()", e); //$NON-NLS-1$
						throwBacktrack(startingOffset, endOffset, line);
					}
					break;
				default :
					return firstExpression;
			}
		}
	}

	/**
	 * @return
	 * @throws EndOfFileException
	 */
	protected boolean queryLookaheadCapability(int count)
			throws EndOfFileException {
		//make sure we can look ahead one before doing this
		boolean result = true;
		try {
			LA(count);
		} catch (EndOfFileException olre) {
			result = false;
		}
		return result;
	}

	protected boolean queryLookaheadCapability() throws EndOfFileException {
		return queryLookaheadCapability(1);
	}

	protected void checkEndOfFile() throws EndOfFileException {
		LA(1);
	}

	protected IASTExpression simpleTypeConstructorExpression(IASTScope scope,
			Kind type, KeywordSetKey key) throws EndOfFileException,
			BacktrackException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		String typeName = consume().getImage();
		consume(IToken.tLPAREN);
		setCurrentFunctionName(typeName);
		IASTExpression inside = expression(scope,
				CompletionKind.CONSTRUCTOR_REFERENCE, key);
		setCurrentFunctionName(EMPTY_STRING);
		int endOffset = consume(IToken.tRPAREN).getEndOffset();
		try {
			return astFactory.createExpression(scope, type, inside, null, null,
					null, null, EMPTY_STRING, null);
		} catch (ASTSemanticException e) {
			throwBacktrack(e.getProblem());
		} catch (Exception e) {
			logException(
					"simpleTypeConstructorExpression::createExpression()", e); //$NON-NLS-1$
			throwBacktrack(startingOffset, endOffset, line);
		}
		return null;
	}

	/**
	 * @param expression
	 * @throws BacktrackException
	 */
	protected IASTExpression primaryExpression(IASTScope scope,
			CompletionKind kind, KeywordSetKey key) throws EndOfFileException,
			BacktrackException {
		IToken t = null;
		switch (LT(1)) {
			// TO DO: we need more literals...
			case IToken.tINTEGER :
				t = consume();
				try {
					return astFactory.createExpression(scope,
							IASTExpression.Kind.PRIMARY_INTEGER_LITERAL, null,
							null, null, null, null, t.getImage(), null);
				} catch (ASTSemanticException e1) {
					throwBacktrack(e1.getProblem());
				} catch (Exception e) {
					logException("primaryExpression_1::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(t.getOffset(), t.getEndOffset(), t.getLineNumber());
				}
			case IToken.tFLOATINGPT :
				t = consume();
				try {
					return astFactory.createExpression(scope,
							IASTExpression.Kind.PRIMARY_FLOAT_LITERAL, null,
							null, null, null, null, t.getImage(), null);
				} catch (ASTSemanticException e2) {
					throwBacktrack(e2.getProblem());
				} catch (Exception e) {
					logException("primaryExpression_2::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(t.getOffset(), t.getEndOffset(), t.getLineNumber());
				}
			case IToken.tSTRING :
			case IToken.tLSTRING :
				t = consume();
				try {
					return astFactory.createExpression(scope,
							IASTExpression.Kind.PRIMARY_STRING_LITERAL, null,
							null, null, null, null, t.getImage(), null);
				} catch (ASTSemanticException e5) {
					throwBacktrack(e5.getProblem());
				} catch (Exception e) {
					logException("primaryExpression_3::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(t.getOffset(), t.getEndOffset(), t.getLineNumber());
				}

			case IToken.t_false :
			case IToken.t_true :
				t = consume();
				try {
					return astFactory.createExpression(scope,
							IASTExpression.Kind.PRIMARY_BOOLEAN_LITERAL, null,
							null, null, null, null, t.getImage(), null);
				} catch (ASTSemanticException e3) {
					throwBacktrack(e3.getProblem());
				} catch (Exception e) {
					logException("primaryExpression_4::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(t.getOffset(), t.getEndOffset(), t.getLineNumber());
				}

			case IToken.tCHAR :
			case IToken.tLCHAR :

				t = consume();
				try {
					return astFactory.createExpression(scope,
							IASTExpression.Kind.PRIMARY_CHAR_LITERAL, null,
							null, null, null, null, t.getImage(), null);
				} catch (ASTSemanticException e4) {
					throwBacktrack(e4.getProblem());
				} catch (Exception e) {
					logException("primaryExpression_5::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(t.getOffset(), t.getEndOffset(), t.getLineNumber());
				}

			case IToken.t_this :
				t = consume(IToken.t_this);
				try {
					return astFactory.createExpression(scope,
							IASTExpression.Kind.PRIMARY_THIS, null, null, null,
							null, null, EMPTY_STRING, null);
				} catch (ASTSemanticException e7) {
					throwBacktrack(e7.getProblem());
				} catch (Exception e) {
					logException("primaryExpression_6::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(t.getOffset(), t.getEndOffset(), t.getLineNumber());
				}
			case IToken.tLPAREN :
				t = consume();
				if (templateIdScopes != null) {
					templateIdScopes.push(new Integer(IToken.tLPAREN));
				}
				IASTExpression lhs = expression(scope, kind, key);
				int endOffset = consume(IToken.tRPAREN).getEndOffset();
				if (templateIdScopes != null) {
					templateIdScopes.pop();
				}
				try {
					return astFactory.createExpression(scope,
							IASTExpression.Kind.PRIMARY_BRACKETED_EXPRESSION,
							lhs, null, null, null, null, EMPTY_STRING, null);
				} catch (ASTSemanticException e6) {
					throwBacktrack(e6.getProblem());
				} catch (Exception e) {
					logException("primaryExpression_7::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(t.getOffset(), endOffset, t.getLineNumber() );
				}
			case IToken.tIDENTIFIER :
			case IToken.tCOLONCOLON :
			case IToken.t_operator :
			case IToken.tCOMPL :
				ITokenDuple duple = null;
				int startingOffset = LA(1).getOffset();
				int line = LA(1).getLineNumber();
				try {
					duple = name(scope, kind, key);
				} catch (BacktrackException bt) {
					IToken mark = mark();
					Declarator d = new Declarator(new DeclarationWrapper(scope,
							mark.getOffset(), mark.getLineNumber(), null));

					if (LT(1) == IToken.tCOLONCOLON
							|| LT(1) == IToken.tIDENTIFIER) {
						IToken start = consume();
						IToken end = null;
						if (start.getType() == IToken.tIDENTIFIER)
							end = consumeTemplateParameters(end);
						while (LT(1) == IToken.tCOLONCOLON
								|| LT(1) == IToken.tIDENTIFIER) {
							end = consume();
							if (end.getType() == IToken.tIDENTIFIER)
								end = consumeTemplateParameters(end);
						}
						if (LT(1) == IToken.t_operator)
							operatorId(d, start, null, kind);
						else {
							backup(mark);
							throwBacktrack(startingOffset, end.getEndOffset(), end.getLineNumber());
						}
					} else if (LT(1) == IToken.t_operator)
						operatorId(d, null, null, kind);

					duple = d.getNameDuple();
				}

				endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
				try {
					return astFactory.createExpression(scope,
							IASTExpression.Kind.ID_EXPRESSION, null, null,
							null, null, duple, EMPTY_STRING, null);
				} catch (ASTSemanticException e8) {
					throwBacktrack(e8.getProblem());
				} catch (Exception e) {
					logException("primaryExpression_8::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(startingOffset, endOffset, line);
				}
			default :
				startingOffset = LA(1).getOffset();
				line = LA(1).getLineNumber();
				if (!queryLookaheadCapability(2)) {
					if (LA(1).canBeAPrefix()) {
						consume();
						checkEndOfFile();
					}
				}
				IASTExpression empty = null;
				try {
					empty = astFactory.createExpression(scope,
							IASTExpression.Kind.PRIMARY_EMPTY, null, null,
							null, null, null, EMPTY_STRING, null);
				} catch (ASTSemanticException e9) {
					throwBacktrack( e9.getProblem() );
					return null;
				} catch (Exception e) {
					logException("primaryExpression_9::createExpression()", e); //$NON-NLS-1$
					throwBacktrack(startingOffset, 0, line);
				}
				return empty;
		}

	}

	/**
	 * Fetches a token from the scanner. 
	 * 
	 * @return				the next token from the scanner
	 * @throws EndOfFileException	thrown when the scanner.nextToken() yields no tokens
	 */
	protected IToken fetchToken() throws EndOfFileException {
		if (limitReached)
			throw new EndOfFileException();

		try {
			IToken value = scanner.nextToken();
			return value;
		} catch (OffsetLimitReachedException olre) {
			limitReached = true;
			handleOffsetLimitException(olre);
			return null;
		} catch (ScannerException e) {
			TraceUtil
					.outputTrace(
							log,
							"ScannerException thrown : ", e.getProblem(), null, null, null); //$NON-NLS-1$
//			log.errorLog("Scanner Exception: " + e.getProblem().getMessage()); //$NON-NLS-1$
			return fetchToken();
		}
	}

	/**
	 * @param value
	 */
	protected void handleNewToken(IToken value) {
	}

	protected void handleOffsetLimitException(
			OffsetLimitReachedException exception) throws EndOfFileException {
		// unexpected, throw EOF instead (equivalent)
		throw new EndOfFileException();
	}

	protected IASTExpression assignmentOperatorExpression(IASTScope scope,
			IASTExpression.Kind kind, IASTExpression lhs,
			CompletionKind completionKind, KeywordSetKey key)
			throws EndOfFileException, BacktrackException {
		IToken t = consume();
		IASTExpression assignmentExpression = assignmentExpression(scope,
				completionKind, key);
		int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
		try {
			return astFactory.createExpression(scope, kind, lhs,
					assignmentExpression, null, null, null, EMPTY_STRING, null);
		} catch (ASTSemanticException e) {
			throwBacktrack(e.getProblem());
		} catch (Exception e) {
			logException("assignmentOperatorExpression::createExpression()", e); //$NON-NLS-1$
			throwBacktrack(t.getOffset(), endOffset, t.getLineNumber());
		}
		return null;
	}

	protected void setCompletionValues(IASTScope scope,
			IASTCompletionNode.CompletionKind kind, KeywordSetKey key)
			throws EndOfFileException {
	}

	protected void setCompletionValues(IASTScope scope,
			IASTCompletionNode.CompletionKind kind, KeywordSetKey key,
			IASTNode node, String prefix) throws EndOfFileException {
	}

	protected void setCompletionValues(IASTScope scope, CompletionKind kind,
			KeywordSetKey key, IASTExpression firstExpression,
			Kind expressionKind) throws EndOfFileException {
	}

	protected void setCompletionValues(IASTScope scope, CompletionKind kind,
			IToken first, IToken last, KeywordSetKey key)
			throws EndOfFileException {
	}

	protected IASTExpression unaryOperatorCastExpression(IASTScope scope,
			IASTExpression.Kind kind, CompletionKind completionKind,
			KeywordSetKey key) throws EndOfFileException, BacktrackException {
		int startingOffset = LA(1).getOffset();
		int line = LA(1).getLineNumber();
		IASTExpression castExpression = castExpression(scope, completionKind,
				key);
		int endOffset = ( lastToken != null ) ? lastToken.getEndOffset() : 0;
		try {
			return astFactory.createExpression(scope, kind, castExpression,
					null, null, null, null, EMPTY_STRING, null);
		} catch (ASTSemanticException e) {
			throwBacktrack(e.getProblem());
		} catch (Exception e) {
			logException("unaryOperatorCastExpression::createExpression()", e); //$NON-NLS-1$
			throwBacktrack(startingOffset, endOffset, line);
		}
		return null;
	}

	protected IASTExpression specialCastExpression(IASTScope scope,
			IASTExpression.Kind kind, KeywordSetKey key)
			throws EndOfFileException, BacktrackException {
		int line = LA(1).getLineNumber();
		int startingOffset = consume().getOffset();
		consume(IToken.tLT);
		IASTTypeId duple = typeId(scope, false, CompletionKind.TYPE_REFERENCE);
		consume(IToken.tGT);
		consume(IToken.tLPAREN);
		IASTExpression lhs = expression(scope,
				CompletionKind.SINGLE_NAME_REFERENCE, key);
		int endOffset = consume(IToken.tRPAREN).getEndOffset();
		try {
			return astFactory.createExpression(scope, kind, lhs, null, null,
					duple, null, EMPTY_STRING, null);
		} catch (ASTSemanticException e) {
			throwBacktrack(e.getProblem());
		} catch (Exception e) {
			logException("specialCastExpression::createExpression()", e); //$NON-NLS-1$
			throwBacktrack(startingOffset, endOffset, line );
		}
		return null;
	}

	public char[] getCurrentFilename() {
		return scanner.getCurrentFilename();
	}

	protected boolean parserTimeout() {
		return false;
	}
	/* (non-Javadoc)
	 * @see org.eclipse.cdt.internal.core.parser.IParserData#getLastToken()
	 */
	public IToken getLastToken() {
		return lastToken;
	}
	/* (non-Javadoc)
	 * @see org.eclipse.cdt.internal.core.parser.IParserData#getParserLanguage()
	 */
	public final ParserLanguage getParserLanguage() {
		return language;
	}
	/**
	 * Parse an identifier.  
	 * 
	 * @throws BacktrackException	request a backtrack
	 */
	public IToken identifier() throws EndOfFileException, BacktrackException {
	    IToken first = consume(IToken.tIDENTIFIER); // throws backtrack if its not that
	    if( first instanceof ITokenDuple ) setGreaterNameContext((ITokenDuple) first);
	    return first;
	}
	/* (non-Javadoc)
	 * @see org.eclipse.cdt.core.parser.IFilenameProvider#getCurrentFileIndex()
	 */
	public int getCurrentFileIndex() {
		return scanner.getCurrentFileIndex();
	}
	/* (non-Javadoc)
	 * @see org.eclipse.cdt.core.parser.IFilenameProvider#getFilenameForIndex(int)
	 */
	public String getFilenameForIndex(int index) {
		return scanner.getFilenameForIndex(index);
	}

	public boolean validateCaches() {
		return true;
	}

	/* (non-Javadoc)
	 * @see java.lang.Object#toString()
	 */
	public String toString() {
		return scanner.toString(); //$NON-NLS-1$
	}

	/**
	 * @return Returns the backtrackCount.
	 */
	public final int getBacktrackCount() {
		return backtrackCount;
	}

	/**
	 * @param bt
	 */
	protected void throwBacktrack(BacktrackException bt) throws BacktrackException {
		throw bt;
	}

	/**
	 * @throws EndOfFileException
	 */
	protected void errorHandling() throws EndOfFileException {
		int depth = ( LT(1) == IToken.tLBRACE ) ? 1 : 0;
	    consume();    
	    while (!((LT(1) == IToken.tSEMI && depth == 0)
	        || (LT(1) == IToken.tRBRACE && depth == 1)))
	    {
	        switch (LT(1))
	        {
	            case IToken.tLBRACE :
	                ++depth;
	                break;
	            case IToken.tRBRACE :
	                --depth;
	                break;
	        }
	        if( depth < 0 )
	        	return;
	        
	        consume();
	    }
	    // eat the SEMI/RBRACE as well
	    consume();
	}
}