/*******************************************************************************
 * Copyright (c) 2004 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
 *******************************************************************************/
/*
 *  $RCSfile: ExpressionProcesser.java,v $
 *  $Revision: 1.11 $  $Date: 2005/05/18 23:11:26 $ 
 */
package org.eclipse.jem.internal.proxy.initParser.tree;

import java.lang.reflect.*;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.List;

import org.eclipse.jem.internal.proxy.common.AmbiguousMethodException;
import org.eclipse.jem.internal.proxy.common.MethodHelper;
import org.eclipse.jem.internal.proxy.initParser.InitializationStringEvaluationException;
import org.eclipse.jem.internal.proxy.initParser.InitializationStringParser;
 
/**
 * Expression processing. This does the actual expression processing with the live objects.
 * It is meant to be subclassed only to provide additional expression types. All of the
 * current expressions cannot be overridden. This is because the stack is very sensitive to 
 * call order.
 * 
 * @since 1.0.0
 */
public class ExpressionProcesser {

	/**
	 * A variable reference for a field access.
	 * 
	 * @since 1.1.0
	 */
	protected static class FieldAccessReference extends VariableReference {
		
		private final Field field;
		private final Object receiver;

		/**
		 * Use this to construct a FieldAccessReference. This will do checks to make sure
		 * it is valid so that exceptions won't be thrown later when actually dereferenced.
		 * 
		 * @param field
		 * @param receiver
		 * @return
		 * @throws IllegalArgumentException
		 * 
		 * @since 1.1.0
		 */
		public static FieldAccessReference createFieldAccessReference(Field field, Object receiver) throws IllegalArgumentException {
			// If static, then receiver is ignored.
			if (!Modifier.isStatic(field.getModifiers())) {
				if (!field.getDeclaringClass().isInstance(receiver))
					throw new IllegalArgumentException(MessageFormat.format(InitparserTreeMessages.getString("ExpressionProcesser.CreateFieldAccessReference.FieldsTypesNotMatching_EXC_"), new Object[]{field.getType(), (receiver!=null ? receiver.getClass() : null)})); //$NON-NLS-1$
			}
			field.setAccessible(true);	// Make it always accessible. Trust it. 
			return new FieldAccessReference(field, receiver);
		}
		
		protected FieldAccessReference(Field field, Object receiver) {
			this.field = field;
			this.receiver = receiver;
		}
		
		
		/* (non-Javadoc)
		 * @see org.eclipse.jem.internal.proxy.initParser.tree.ExpressionProcesser.VariableReference#dereference()
		 */
		public Object dereference() {
			try {
				return field.get(receiver);
			} catch (IllegalArgumentException e) {
				// Shouldn't occur. Already tested for this.
				e.printStackTrace();
			} catch (IllegalAccessException e) {
				// Shouldn't occur. Already tested for this.
				e.printStackTrace();
			}
			return null;
		}
		
		
		/* (non-Javadoc)
		 * @see org.eclipse.jem.internal.proxy.initParser.tree.ExpressionProcesser.VariableReference#set(java.lang.Object, java.lang.Class)
		 */
		public Object set(Object value, Class type) throws IllegalArgumentException, IllegalAccessException {
			field.set(receiver, value);
			return field.get(receiver);	// Just in case some conversion happened. Technically it is not the value set but the retrieved when in an assignment.
		}
		
		
		/* (non-Javadoc)
		 * @see java.lang.Object#toString()
		 */
		public String toString() {
			return "FieldAccess{"+field.toString()+"} on "+receiver.toString(); //$NON-NLS-1$ //$NON-NLS-2$
		}
	}
	
	/**
	 * A variable reference for an Array access. It will reference only the last indexed entry of the array.
	 * For example if <code>x[3][4]</code> is the access, then what will be given to this reference will be
	 * the array entry at x[3][4], not the x array itself.
	 * 
	 * @since 1.1.0
	 */
	protected static class ArrayAccessReference extends VariableReference {
		
		
		private final Object array;
		private final int index;

		/**
		 * Use this to construct an array access reference. This will do checks to make sure
		 * it is valid so that exceptions won't be thrown later when actually dereferenced.
		 * 
		 * @param array
		 * @param index
		 * @return
		 * @throws IllegalArgumentException
		 * 
		 * @since 1.1.0
		 */
		public static ArrayAccessReference createArrayAccessReference(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
			int len = Array.getLength(array);
			if (index < 0 || len <= index)
				throw new ArrayIndexOutOfBoundsException(MessageFormat.format(InitparserTreeMessages.getString("ExpressionProcesser.CreateArrayAccessReference.OutOfBounds_EXC_"), new Object[]{new Integer(index), new Integer(len)})); //$NON-NLS-1$
			return new ArrayAccessReference(array, index);
		}
		/**
		 * Construct the reference with the array and the index of the entry being referenced.
		 * @param array
		 * @param index
		 * 
		 * @since 1.1.0
		 */
		protected ArrayAccessReference(Object array, int index) {
			this.array = array;
			this.index = index;
		}
		
		
		/* (non-Javadoc)
		 * @see org.eclipse.jem.internal.proxy.initParser.tree.VariableReference#dereference()
		 */
		public Object dereference() {
			return Array.get(array, index);
		}
		
		
		/* (non-Javadoc)
		 * @see org.eclipse.jem.internal.proxy.initParser.tree.VariableReference#set(java.lang.Object, java.lang.Class)
		 */
		public Object set(Object value, Class type) throws IllegalArgumentException {
			Array.set(array, index, value);
			return Array.get(array, index);	// In case there was some conversion applied. Technically it is not the value set but the retrieved when in an assignment.
		}
		
		
		/* (non-Javadoc)
		 * @see java.lang.Object#toString()
		 */
		public String toString() {
			return "ArrayAccess["+index+"]: "+array.toString(); //$NON-NLS-1$ //$NON-NLS-2$
		}
	}
	
	/**
	 * The expression result stack and the expression result type stack.
	 * The type stack is used to be expected type of the corresponding
	 * expression result. This is needed for converting to primitives
	 * and for finding correct method call from the argument types. In
	 * this case, it is not the true value, but the value expected, e.g.
	 * <code>Object getObject()</code> returns something of type Object.
	 * This needs to be maintained so that if it goes into another method
	 * we don't accidently return a more specific method instead of the
	 * one that takes Object as an argument. 
	 * 
	 * expressionStack has result of the expression.
	 * expressionTypeStack has the computed type of the expression i.e.
	 * the type that the expression returns, not the type of the value.
	 * These can be different because the expression (e.g. method) may
	 * return an Object, but the expression value will be some specific
	 * subclass. So the expressionTypeStack would have a <code>java.lang.Object.class</code>
	 * on it in that case.
	 * Note: if the expressionStack has a <code>null</code> on it, then the type stack
	 * may either have a specific type in it, or it may be <code>MethodHelper.NULL_TYPE</code>. It
	 * would be this if it was explicitly pushed in and not as the
	 * result of a computation. If the result of a computation, it would have the
	 * true value.
	 * Note: if the expressionStack has a <code>Void.type</code> on it, then that
	 * means the previous expression had no result. This is an error if trying to
	 * use the expression in another expression.
	 * 
	 * @see org.eclipse.jem.internal.proxy.initParser.MethodHelper#NULL_TYPE
	 */
	private List expressionStack = new ArrayList(10);
	private List expressionTypeStack = new ArrayList(10);
	
	/**
	 * List of the expression proxies. The index into the list is the
	 * same as the expression proxy id. 
	 */
	private ArrayList expressionProxies;	// It is array list because we want to call ensureCapacity and that is not available on List.
	
	/**
	 * An error has occurred. At this point all subcommands will simply make sure they flush the input stream
	 * correctly, but they do not process it.
	 * 
	 * @since 1.0.0
	 */
	private boolean errorOccurred = false;
	private boolean novalueException = false;
	
	private Throwable exception = null;	// Was there another kind of exception that was caught.
	
	/**
	 * Process all other exceptions then the NoExpressionValueException. This can be called from usage code so that if there was an error
	 * in setting up for a call to the processer it can be logged.
	 * 
	 * @param e
	 * 
	 * @since 1.0.0
	 */
	public final void processException(Throwable e) {
		// Process all other exceptions.
		novalueException = false;
		while (e.getCause() != null)
			e = e.getCause();
		if (traceOn) {
			System.out.println();
			System.out.print("***** >>>\tException: "); //$NON-NLS-1$
			System.out.println(e);
		}
		throwException(e);	// Treat as a throw to let try/catches expressions handle it.
	}
	
	/**
	 * This is a syntax exception. This means data coming across is corrupted in
	 * some way so no further processing should occur. 
	 * @param e
	 * 
	 * @since 1.1.0
	 */
	protected final void processSyntaxException(Throwable e) {
		errorOccurred = true;
		novalueException = false;
		exception = e;		
	}
		
	/**
	 * Process a NoExpressionValueException. Don't wrapper these.
	 * @param e
	 * 
	 * @since 1.1.0
	 */
	protected final void processSyntaxException(NoExpressionValueException e) {
		if (traceOn)
			printTrace("Expression has no value", false); //$NON-NLS-1$
		try {
			errorOccurred = true;
			novalueException = true;
			exception = e;
		} finally {
			if (traceOn)
				printTraceEnd();
		}
	}
	
	/**
	 * Return whether there are any errors.
	 * 
	 * @return <code>true</code> if no errors.
	 * 
	 * @since 1.0.0
	 */
	public boolean noErrors() {
		return !errorOccurred;
	}
	
	/**
	 * Return whether the error is a NoExpressionValueException or not.
	 * @return
	 * 
	 * @since 1.1.0
	 */
	public boolean isNoExpressionValue() {
		return novalueException;
	}
	
	/**
	 * Return the throwable if a Throwable was caught.
	 * 
	 * @return The throwable, or <code>null</code> if not set.
	 * 
	 * @since 1.0.0
	 */
	public Throwable getErrorThrowable() {
		return exception;
	}

	/**
	 * Push the expression value and its expected type.
	 * @param o
	 * @param type
	 * 
	 * @since 1.0.0
	 */
	protected final void pushExpressionValue(Object o, Class type) {
		expressionStack.add(o);
		expressionTypeStack.add(type);
	}

	/**
	 * Pop just the expression value. It is imperitive that the expression type
	 * is popped immediately following. Separated the methods so that we
	 * don't need to create an array to return two values. This will dereference
	 * any variable references.
	 * 
	 * @return The value.
	 * @throws NoExpressionValueException
	 * 
	 * @since 1.0.0
	 */
	protected final Object popExpression() throws NoExpressionValueException {
		return popExpression(true);
	}
	
	/**
	 * Pop just the expression value. It is imperitive that the expression type
	 * is popped immediately following. Separated the methods so that we
	 * don't need to create an array to return two values.
	 * 
	 * @param deReference If the top expression is a Reference, then dereference it.
	 * @return The value.
	 * @throws NoExpressionValueException
	 * 
	 * @since 1.0.0
	 */
	protected final Object popExpression(boolean deReference) throws NoExpressionValueException {
		try {
			Object result = expressionStack.remove(expressionStack.size()-1);
			if (deReference && result instanceof VariableReference)
				result = ((VariableReference) result).dereference();
			return result;
		} catch (IndexOutOfBoundsException e) {
			throw new NoExpressionValueException();
		}
	}

	/**
	 * Get the expression at <code>fromTop</code> down from the top. This is
	 * need for when multi-operators happen and they are stored in reverse of 
	 * what is needed. They would normally be stored left to right, with the
	 * rightmost one on top. But they need to be processed left to right, so
	 * to get the left most one requires digging down in the stack.
	 * <p>
	 * When done, <code>popExpressions(int count)</code> must be called to
	 * clean them out since they were processed.
	 * <p>
	 * This will not dereference the expression. It is the job of the caller to do this. 
	 *  
	 * @param fromTop <code>1</code> is the top one, <code>2</code> is the next one down.
	 * @return The entry from the top that was requested.
	 * @throws NoExpressionValueException
	 * 
	 * @see IDEExpression#popExpressions(int)
	 * @since 1.0.0
	 */
	protected final Object getExpression(int fromTop) throws NoExpressionValueException {
		try {
			return expressionStack.get(expressionStack.size()-fromTop);
		} catch (IndexOutOfBoundsException e) {
			throw new NoExpressionValueException();
		}
	}
	
	/**
	 * Remove the top <code>count</code> items. This will not cause dereferencing to occur. It
	 * removes the corresponding type stack entries.
	 * 
	 * @param count
	 * @throws NoExpressionValueException
	 * 
	 * @since 1.0.0
	 */
	protected final void popExpressions(int count) throws NoExpressionValueException {
		try {
			int remove = expressionStack.size()-1;
			while (count-- > 0) {
				expressionStack.remove(remove);
				expressionTypeStack.remove(remove--);
			}
		} catch (IndexOutOfBoundsException e) {
			throw new NoExpressionValueException();
		}
	}
	
	/**
	 * Pop just the expression type. It is imperitive that the expression type
	 * is popped immediately following popExpression. Separated the methods so that we
	 * don't need to create an array to return two values.
	 * <p>
	 * If the allowVoid is false and type is void, then a NoExpressionValueException will be thrown.
	 * This is for the case where the expression was trying to be used in a different
	 * expression. This will be set to void only on expressions that return no value (only
	 * method's do this for now).
	 * 
	 * @param allowVoid Allow void types if <code>true</code>
	 * @return The type.
	 * @throws NoExpressionValueException
	 * @since 1.0.0
	 */
	protected final Class popExpressionType(boolean allowVoid) throws NoExpressionValueException {
		try {
			Class result = (Class) expressionTypeStack.remove(expressionTypeStack.size()-1);
			if (!allowVoid && result == Void.TYPE)
				throw new NoExpressionValueException(InitparserTreeMessages.getString("ExpressionProcesser.PopExpressionType.ExpressionVoid_EXC_")); //$NON-NLS-1$
			return result;
				
		} catch (IndexOutOfBoundsException e) {
			throw new NoExpressionValueException();
		}
	}

	/**
	 * Get the expression type at <code>fromTop</code> down from the top. This is
	 * need for when multi-operators happen and they are stored in reverse of 
	 * what is needed. They would normally be stored left to right, with the
	 * rightmost one on top. But they need to be processed left to right, so
	 * to get the left most one requires digging down in the stack.
	 * <p>
	 * When done, <code>popExpressionTypes(int count)</code> must be called to
	 * clean them out since they were processed.

	 * @param fromTop <code>1</code> is the top one, <code>2</code> is the next one down.
	 * @param allowVoid Allow void types if <code>true</code>
	 * @return The type from the top that was requested.
	 * @throws ThrowableProxy
	 * @throws NoExpressionValueException
	 * 
	 * @see IDEExpression#popExpressionTypes(int)
	 * @since 1.0.0
	 */
	protected final Class getExpressionType(int fromTop, boolean allowVoid) throws NoExpressionValueException {
		try {
			Class result = (Class) expressionTypeStack.get(expressionTypeStack.size()-fromTop);
			if (!allowVoid && result == Void.TYPE)
				throw new NoExpressionValueException();
			return result;
		} catch (IndexOutOfBoundsException e) {
			throw new NoExpressionValueException();
		}
	}
	
	/**
	 * Flag indicating expression should be ignored and not processed.
	 * This happens because of few cases, like conditional and, that
	 * if one returns false, the rest of the expressions in that conditional and
	 * expression should be ignored and not processed.
	 * <p>
	 * It is an Object that acts as an enum for the type of expression that initiated the ignore. 
	 * If it is <code>null</code> then no one is ignoring. 
	 * <p>
	 * All of the pushTo...Proxy methods must test this for this to work correctly.
	 * Each expression has some way of testing that their particular nesting of 
	 * expressions is complete and they can turn off the ignore flag.
	 * <p>
	 * Only one type of ignore can exist at a time.
	 */
	protected Object ignoreExpression = null;	
	
	
	private List saveStates;
	
	/**
	 * Are we tracing or not.
	 */
	protected final boolean traceOn;
	private final long thresholdTime;
	private long startExpressionStepTime;
	private long startExpressionTime;
	private long lastExpressionEndTime;
	
	/**
	 * Trace head of this expression. So that traces from different expressions can be distinquished.
	 * It is simply an monotonically increasing counter. It is the header string for any trace output.
	 */
	protected final String traceHeader;
	
	private int indent = 0;	// Indented for certain block expressions.
	
	/*
	 * Trace counter. It is incremented once for each expression and assigned to the traceId of the expression.
	 */
	private static int TRACE_COUNTER;
	
	/**
	 * Create the Expression without tracing.
	 * @param registry
	 * 
	 * @since 1.0.0
	 */
	public ExpressionProcesser() {
		this(false, -1);
	}
	
	/**
	 * Create the expression, and set the tracing mode and threshold time. Use -1
	 * for default time of 100ms.
	 * @param traceOn
	 * 
	 * @since 1.1.0
	 */
	public ExpressionProcesser(boolean traceOn, long threshold) {
		this.traceOn = traceOn;
		if (traceOn) {
			traceHeader = "**"+(++TRACE_COUNTER)+':'; //$NON-NLS-1$
			System.out.print(traceHeader);
			System.out.println(" Start expression"); //$NON-NLS-1$
			this.thresholdTime = threshold != -1 ? threshold : 100;
			lastExpressionEndTime = startExpressionTime = System.currentTimeMillis();
		} else {
			traceHeader = null;
			thresholdTime = 100;
		}
	}
	
	/**
	 * Trace msg helper. Should only be called if traceOn is true. This method is only used to start a new trace message.
	 * The caller is must call printTraceEnd at the end.
	 *  
	 * @param msg message to print
	 * @param ignore are we ignoring the expression, or is it being processed (this just alters the trace output slightly).
	 * 
	 * @since 1.1.0
	 */
	protected void printTrace(String msg, boolean ignore) {
		startExpressionStepTime = System.currentTimeMillis();
		long sinceLastExpression = startExpressionStepTime - lastExpressionEndTime;
		System.out.print(traceHeader);
		if (sinceLastExpression > 0) {
			System.out.print('(');
			if (sinceLastExpression > thresholdTime)
				System.out.print("***"); //$NON-NLS-1$
			System.out.print(sinceLastExpression);
			System.out.print("ms)"); //$NON-NLS-1$
		}
		System.out.print('\t');
		if (!ignore)
			System.out.print("\t"); //$NON-NLS-1$
		else
			System.out.print("##\t"); //$NON-NLS-1$
		
		printIndent();
		System.out.print(msg);
	}
	
	/**
	 * print the indent. It will not do a new line before nor after.
	 * 
	 * @since 1.1.0
	 */
	protected void printIndent() {
		for(int i=indent; i>0; i--) {
			System.out.print("  "); //$NON-NLS-1$
		}
	}

	protected void printTraceEnd() {
		long stop = System.currentTimeMillis()-startExpressionStepTime;
		if (stop > 0) {
			System.out.print(" ("); //$NON-NLS-1$
			if (stop > thresholdTime)
				System.out.print("***"); //$NON-NLS-1$
			System.out.print(stop);
			System.out.print("ms)"); //$NON-NLS-1$
		}
		System.out.println();
		lastExpressionEndTime = System.currentTimeMillis();
	}
	
	/**
	 * Do an indent (undent) according to indent flag.
	 * @param indent <code>true</code> to increment indent, or otherwise decrement.
	 * 
	 * @since 1.1.0
	 */
	protected void indent(boolean indent) {
		this.indent += (indent ? 1 : -1);
		if (this.indent < 0)
			this.indent = 0;
	}
	
	/**
	 * Print the object and type. It will not end with a newline char, so one will be needed afterwards.
	 * 
	 * @param o
	 * @param t
	 * 
	 * @since 1.1.0
	 */
	protected void printObjectAndType(Object o, Class t) {
		System.out.print(' ');
		System.out.print("Object-"); //$NON-NLS-1$
		System.out.print(o);
		System.out.print(" Type-"); //$NON-NLS-1$
		System.out.print(t);
		System.out.print(' ');
	}
	
	/**
	 * Close the exception processing
	 * 
	 * @since 1.0.0
	 */
	public final void close() {
		boolean firstClose = expressionStack != null;
		if (firstClose && traceOn) {
			printTrace("End expression", false); //$NON-NLS-1$
			long totalTime = System.currentTimeMillis()-startExpressionTime;
			System.out.print(" Total expression evaluation time: "); //$NON-NLS-1$
			System.out.print(totalTime);
			System.out.print("ms."); //$NON-NLS-1$
		}
		try {
			expressionStack = null;
			expressionTypeStack = null;
			expressionProxies = null;
			exception = null;
			catchThrowable = null;
			saveStates = null;
		} finally {
			if (firstClose && traceOn)
				printTraceEnd();
		}
	}

	/**
	 * Pull the value. The value will be placed into the array passed in.
	 * It will be stored as value[0] = value value[1] = valuetype(Class).
	 * 
	 * @param value The value array to store the value and type into.
	 * @throws NoExpressionValueException
	 * @since 1.0.0
	 */
	public final void pullValue(Object[] value) throws NoExpressionValueException {
		if (traceOn)
			printTrace("Pull value:", false); //$NON-NLS-1$
		try {
			value[0] = popExpression();
			value[1] = popExpressionType(false);
		} finally {
			if (traceOn) {
				printObjectAndType(value[0], (Class) value[1]);
				printTraceEnd();
			}
		}
		close();
	}
	
	/**
	 * Pull the value of the expression proxy, dereferencing it if necessary. This is for resolution only purposes at the
	 * end of the expression being processed. Not meant for general access to the value of expression proxy. Use 
	 * {@link ExpressionProcesser#getExpressionProxyValue(int, Object[])} instead for general access to the value.
	 * 
	 * @param proxyid
	 * @param value
	 * @throws NoExpressionValueException
	 * 
	 * @since 1.1.0
	 */
	public final void pullExpressionProxyValue(int proxyid, Object[] value) throws NoExpressionValueException {
		getExpressionProxyValue(proxyid, value, true, true);
	}
	
	/**
	 * Get the expression proxy value. If the expression has not yet been evaluated it will
	 * return false. If it has it will return true.
	 * @param proxyid
	 * @param value put value into value[0] and the type into value[1].
	 * @return <code>true</code> if successful, or <code>false</code> if the expression proxy was never resolved or doesn't exist.
	 * 
	 * @since 1.1.0
	 */
	public boolean getExpressionProxyValue(int proxyid, Object[] value) {
		try {
			return getExpressionProxyValue(proxyid, value, true, false);
		} catch (NoExpressionValueException e) {
			return false;
		}
	}
	
	/*
	 * Internal method use to actually get the value, but to distinquish between pull and get of the public interface.
	 * Get will process the errors as normal execution errors, while pull will throw the errors. finalTrace is when
	 * this is the final call to return the values to the client. We will trace the results in that case.
	 * Return true if successful.
	 */
	private boolean getExpressionProxyValue(int proxyid, Object[] value, boolean pull, boolean finalTrace) throws NoExpressionValueException {
		// Note: This will throw the exceptions right away since this is called from outside to fill in the value and
		// so we are holding such exceptions.
		boolean doTrace = finalTrace && traceOn;
		try {
			if (expressionProxies != null && expressionProxies.size() > proxyid) {
				InternalExpressionProxy proxy = (InternalExpressionProxy) expressionProxies.get(proxyid);
				if (proxy != null && proxy.isSet()) {
					value[0] = proxy.getValue();
					if (value[0] instanceof VariableReference)
						value[0] = ((VariableReference) value[0]).dereference(); // Here we want the final current value.
					value[1] = proxy.getType();
					if (doTrace)
						if (value[1] != Void.TYPE) {
							printTrace("Return Proxy #" + proxyid + " Resolved to", false); //$NON-NLS-1$ //$NON-NLS-2$
							printObjectAndType(value[0], (Class) value[1]);
						} else
							printTrace("Return Proxy #" + proxyid + " Resolved to void.", false); //$NON-NLS-1$ //$NON-NLS-2$
					return true;

				} else {
					if (doTrace)
						printTrace("Return Proxy #" + proxyid + ": Not resolved", false); //$NON-NLS-1$ //$NON-NLS-2$
					NoExpressionValueException e = new NoExpressionValueException(InitparserTreeMessages.getString("ExpressionProcesser.GetExpressionProxyValue.ExpressionProxyNotSet_EXC_")); //$NON-NLS-1$
					if (pull)
						throw e;
					else
						processSyntaxException(e);
					return false;
				}
			} else {
				if (doTrace)
					printTrace("Return Proxy #" + proxyid + ": Never created.", false); //$NON-NLS-1$ //$NON-NLS-2$
				NoExpressionValueException e = new NoExpressionValueException(InitparserTreeMessages.getString("ExpressionProcesser.GetExpressionProxyValue.ExpressionProxyDoesntExist_EXC_")); //$NON-NLS-1$
				if (pull)
					throw e;
				else
					processSyntaxException(e);
				return false;
			}
		} finally {
			if (doTrace)
				printTraceEnd();
		}
	}
	
	/**
	 * Push the expression (just a value) onto the stack.
	 * 
	 * @param o
	 * @param t
	 * 
	 * @since 1.0.0
	 */
	public final void pushExpression(Object o, Class t) {
		boolean ignore = (ignoreExpression != null || errorOccurred);
		if (traceOn) {
			printTrace("Push: ", ignore); //$NON-NLS-1$
			printObjectAndType(o, t);
		}
		try {
			if (ignore)
				return;
			pushExpressionValue(o, t);
		} finally {
			if (traceOn)
				printTraceEnd();
		}
	}
	
	/**
	 * Get the value of the expression proxy (from proxy id), and push the value onto the stack.
	 *  
	 * @param proxyid The proxy id of the ExpressionProxy to push as a value.
	 * 
	 * @since 1.0.0
	 */
	public final void pushExpressionProxy(int proxyid) {
		boolean ignore =(ignoreExpression != null || errorOccurred);
		if (traceOn)
			printTrace("Push Expression Proxy #"+proxyid, ignore); //$NON-NLS-1$
		try {
			if (ignore)
				return;
			if (expressionProxies != null && expressionProxies.size() > proxyid) {
				InternalExpressionProxy proxy = (InternalExpressionProxy) expressionProxies.get(proxyid);
				if (proxy != null && proxy.isSet()) {
					if (traceOn)
						printObjectAndType(proxy.getValue(), proxy.getType());
					pushExpressionValue(proxy.getValue(), proxy.getType());	// Can push a VariableReference. This is ok. When used it will then deref with the current value.
				} else
					processSyntaxException(new NoExpressionValueException());
			} else
				processSyntaxException(new NoExpressionValueException());
		} finally {
			if (traceOn)
				printTraceEnd();
		}
	}
	
	/**
	 * Push a cast onto stack. The type passed in is either a String (with classname to cast to) or the
	 * type to cast to.
	 * @param type To cast to. If <code>String</code> then convert to type (using something like <code>Class.forName()</code>) or it is a Class
	 * 
	 * @since 1.0.0
	 */
	public final void pushCast(Class type) {
		boolean ignore = (ignoreExpression != null || errorOccurred);
		if (traceOn)
			printTrace("Cast to: "+type, ignore); //$NON-NLS-1$
		try {
			if (ignore)
				return;
			
			try {
				Object exp = popExpression();
				Class exptype = popExpressionType(false);
				
				pushExpressionValue(castBean(type, exp, exptype), type);
			} catch (RuntimeException e) {
				processException(e);
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
			
	}
	
	/**
	 * Cast a bean into the return type. If the return type is not primitive, then
	 * the bean is left alone, however it is checked to be an instance of
	 * the return type. If the return type is primitive, then the
	 * correct primitive wrapper is created from the bean (bean must be a number or character or boolean primitve so
	 * that cast will work).
	 * <p>
	 * However if can't be cast for primitive or if not an instance of the
	 * returntype for objects, a ClassCastException will be raised.
	 * <p>
	 * This is a helper method for expression processer to cast a bean. Since it is a helper method it doesn't
	 * check nor process the exception. It throws it. Callers must handle it as they see fit.
	 * 
	 * @param returnType
	 * @param bean
	 * @param beanType The type that bean is supposed to be (e.g. even though it is a Number, it actually represents a primitive).
	 * @return The cast bean (either to the appropriate primitive wrapper type or bean)
	 * 
	 * @throws ClassCastException
	 * @since 1.0.0
	 */
	protected final Object castBean(Class returnType, Object bean, Class beanType) throws ClassCastException {
		// Cast uses true value and true class of bean, not expected type (i.e. not beanType).
		if (bean == null)
			if (!returnType.isPrimitive())
				return bean;	// bean is null, and return type is not primitive, so this is a valid cast.
			else 
				throwClassCast(returnType, bean);
		else if (returnType.equals(bean.getClass()))
			return bean;	// They are already the same.
		else if (!returnType.isPrimitive()) {
			if (!beanType.isPrimitive() && returnType.isInstance(bean))
				return bean;
			else
				throwClassCast(returnType, bean);	// Either bean type was wrappering primitive or not instanceof returntype.
		} else {
			if (!beanType.isPrimitive())
				throwClassCast(returnType, bean);	// bean type was not wrappering a primitive. Can't cast to primitive.
			// It is return type of primitive. Now convert to correct primitive.
			if (returnType == Boolean.TYPE)
				if (bean instanceof Boolean)
					return bean;
				else
					throwClassCast(returnType, bean);
			else {
				if (bean instanceof Number) {
					if (returnType == Integer.TYPE)
						if (bean instanceof Integer)
							return bean;
						else
							return new Integer(((Number) bean).intValue());
					else if (returnType == Byte.TYPE)
						if (bean instanceof Byte)
							return bean;
						else
							return new Byte(((Number) bean).byteValue());
					else if (returnType == Character.TYPE)
						if (bean instanceof Character)
							return bean;
						else
							return new Character((char) ((Number) bean).intValue());
					else if (returnType == Double.TYPE)
						if (bean instanceof Double)
							return bean;
						else
							return new Double(((Number) bean).doubleValue());
					else if (returnType == Float.TYPE)
						if (bean instanceof Float)
							return bean;
						else
							return new Float(((Number) bean).floatValue());
					else if (returnType == Long.TYPE)
						if (bean instanceof Long)
							return bean;
						else
							return new Long(((Number) bean).longValue());
					else if (returnType == Short.TYPE)
						if (bean instanceof Short)
							return bean;
						else
							return new Short(((Number) bean).shortValue());	
					else
						throwClassCast(returnType, bean);
				} else if (bean instanceof Character) {
					if (returnType == Character.TYPE)
						return bean;
					else if (returnType == Integer.TYPE)
						return new Integer(((Character) bean).charValue());
					else if (returnType == Byte.TYPE)
						return new Byte((byte) ((Character) bean).charValue());
					else if (returnType == Double.TYPE)
						return new Double(((Character) bean).charValue());
					else if (returnType == Float.TYPE)
						return new Float(((Character) bean).charValue());
					else if (returnType == Long.TYPE)
						return new Long(((Character) bean).charValue());
					else if (returnType == Short.TYPE)
						return new Short((short) ((Character) bean).charValue());	
					else
						throwClassCast(returnType, bean);
				} else
					throwClassCast(returnType, bean);
			}
			
		}
		return null;	// It should never get here;
	}
	
	private void throwClassCast(Class returnType, Object bean) throws ClassCastException {
		throw new ClassCastException(MessageFormat.format(InitparserTreeMessages.getString("ExpressionProcesser.CannotCastXToY_EXC_"), new Object[] {bean != null ? bean.getClass().getName() : null, returnType.getName()})); //$NON-NLS-1$
	}

	/**
	 * Return the primitive type that the wrapper bean represents (i.e. Boolean instance returns Boolean.TYPE) 
	 * <p>
	 * This is a helper method for expression processer to get the primitive type. Since it is a helper method it doesn't
	 * check nor process the exception. It throws it. Callers must handle it as they see fit.

	 * @param bean
	 * @return the primitive type class of the given bean.
	 * @throws IllegalArgumentException if bean is <code>null</code> or not of the type that can be converted to a primitive.
	 * 
	 * @since 1.0.0
	 */
	protected final Class getPrimitiveType(Object bean) throws IllegalArgumentException {
		if (bean instanceof Boolean)
			return Boolean.TYPE;
		else if (bean instanceof Integer)
			return Integer.TYPE;
		else if (bean instanceof Byte)
			return Byte.TYPE;
		else if (bean instanceof Character)
			return Character.TYPE;
		else if (bean instanceof Double)
			return Double.TYPE;
		else if (bean instanceof Float)
			return Float.TYPE;
		else if (bean instanceof Long)
			return Long.TYPE;
		else if (bean instanceof Short)
			return Short.TYPE;
		else
			throw new IllegalArgumentException(bean != null ? bean.getClass().getName() : "null"); //$NON-NLS-1$
	}
	
	private static final Object IFELSE_IGNORE = "IF/ELSE IGNORE";	// Flag for if/else in ingore //$NON-NLS-1$
	private int ifElseNesting = 0;	// Nesting of if/else expressions.
	private int ifElseIgnoreNestCount = 0;	// When ignoring if/else expressions, ignore until this nest count.
	private boolean ifElseSkipTruePart;

	
	/**
	 * Push an if test expression.
	 * @param hasElseClause
	 * 
	 * @since 1.0.0
	 */
	public final void pushIfElse() {
		try {
			boolean ignore = true;
			try {
				if (errorOccurred)
					return;
				// Slightly different here in that if an ignoring occurred we still need to process at least part of it so that
				// we can get the expression grouping correct.
				ifElseNesting++;	// We have the test.
	
				if (ignoreExpression != null)
					return;
				ignore = false;
			} finally {
				if (traceOn)
					printTrace("If test condition", ignore); //$NON-NLS-1$
			}
					
			try {
				Object condition = popExpression();
				Class type = popExpressionType(false);
				if (type != Boolean.TYPE)
					throwClassCast(Boolean.TYPE, condition);
				if (traceOn) {
					System.out.print(" Test Result="+condition); //$NON-NLS-1$
					printTraceEnd();
					indent(true);
					printTrace("Begin True Expression.", ignore); //$NON-NLS-1$
					printTraceEnd();
					indent(true);
				}				
				if (((Boolean) condition).booleanValue()) {
					// Condition was true.
					// Do nothing. Let true condition be processed.
				} else {
					// Condition was false.
					ifElseSkipTruePart = true;	// Tell the true condition should be ignored.
					ignoreExpression = IFELSE_IGNORE;
					ifElseIgnoreNestCount = ifElseNesting;
				}
				// We don't put anything back on the stack because the condition test is not ever returned.
				// The appropriate true or false condition evaluation will be left on the stack.
			} catch (RuntimeException e) {
				processException(e);
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
	}

	/**
	 * Push an if/else clause. It can be any clause of the if (true, or false clause).
	 * @param clauseType
	 * 
	 * @since 1.0.0
	 */
	public final void pushIfElse(InternalIfElseOperandType clauseType) {
		try {
			boolean ignore = true;
			if (errorOccurred)
				return;
			// Slightly different here in that if an ignoring occurred we still need to process at least part of it so that
			// we can get the expression grouping correct.
			switch (clauseType.getValue()) {
			case InternalIfElseOperandType.TRUE_CLAUSE_VALUE:
					if (traceOn) {
						indent(false);
						printTrace("Begin False Expression.", ignore); //$NON-NLS-1$
						printTraceEnd();
						indent(true);
					}
					if (ifElseSkipTruePart && ignoreExpression == IFELSE_IGNORE && ifElseIgnoreNestCount == ifElseNesting) {
						// stop ignoring, we've ignored the true condition of interest.
						ignoreExpression = null;
						return; // However, leave because since this condition was ignored.
					}
					break;
				case InternalIfElseOperandType.ELSE_CLAUSE_VALUE:
					if (traceOn) {
						indent(false);
						indent(false);
						printTrace("End IF/ELSE Expression.", ignore); //$NON-NLS-1$
						printTraceEnd();
					}					
					int currentNesting = ifElseNesting--;
					if (ignoreExpression == IFELSE_IGNORE && ifElseIgnoreNestCount == currentNesting) {
						// stop ignoring, we've ignored the false condition of interest.
						ignoreExpression = null;
						return; // However, leave because since this condition was ignored.
					}
			}
	
				if (ignoreExpression != null)
					return;
				ignore = false;

					
			try {
				switch (clauseType.getValue()) {
					case InternalIfElseOperandType.TRUE_CLAUSE_VALUE:
						ifElseSkipTruePart = false;	// Tell the false condition should be ignored.
						ignoreExpression = IFELSE_IGNORE;
						ifElseIgnoreNestCount = ifElseNesting;
						break;
					case InternalIfElseOperandType.ELSE_CLAUSE_VALUE:
						// There's nothing to do, if it was ignored due to true, we wouldn't of gotton here.
						// If it wasn't ignored, then the result of the false expression is on the stack, which is what it should be.
						break;
				}
			} catch (RuntimeException e) {
				processException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
	}

	/**
	 * Push the instanceof expression.  The type passed in is either a String (with classname to test against) or the
	 * type to test against.
	 * @param type To test against.
	 * @since 1.0.0
	 */
	public final void pushInstanceof(Class type) {
		boolean ignore = (ignoreExpression != null || errorOccurred);
		if (traceOn)
			printTrace("Instanceof type: "+type, ignore); //$NON-NLS-1$
		try {
			if (ignore)
				return;
			
			try {
				Object exp = popExpression();
				Class exptype = popExpressionType(false);
				pushExpressionValue(Boolean.valueOf(isInstance(type, exp, exptype)), Boolean.TYPE);
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			} catch (RuntimeException e) {
				processException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
	}
	
	/**
	 * Test if instance of. It will make sure that primitive to non-primitive is not permitted.
	 * This is a true instance of, which means null IS NOT AN instance of any type. This is
	 * different then assignable from, in that case null can be assigned to any class type.
	 * <p>
	 * This is a helper method for expression processer to do isInstance. Since it is a helper method it doesn't
	 * check nor process exceptions.

	 * @param type
	 * @param bean
	 * @param beanType
	 * @return
	 * 
	 * @since 1.0.0
	 */
	protected final boolean isInstance(Class type, Object bean, Class beanType) {
		if (type.isPrimitive())
			return beanType.isPrimitive() && type == beanType;	// Can't use isInstance because for a primitive type isInstance returns false.
		else 
			return type.isInstance(bean);
	}
	
	/**
	 * Push new instance from string.
	 * @param initializationString
	 * @param resultType expected result type. If it isn't of that type, a classcast will be processed. 
	 * @param classloader classloader to use for finding classes, or <code>null</code> to use classloader of InitializationStringParser.class.
	 * 
	 * @since 1.1.0
	 */
	public final void pushNewInstanceFromString(String initializationString, Class resultType, ClassLoader classloader) {
		boolean ignore = (ignoreExpression != null || errorOccurred);
		if (traceOn)
			printTrace("New instance from string: \""+initializationString+"\" Type="+resultType, ignore); //$NON-NLS-1$ //$NON-NLS-2$
		try {
			if (ignore)
				return;
			
			try {
				InitializationStringParser parser = InitializationStringParser.createParser(initializationString, classloader);
				Object newValue = parser.evaluate();
				newValue = castBean(resultType, newValue, parser.getExpectedType());
				pushExpressionValue(newValue, resultType);
			} catch (RuntimeException e) {
				processException(e);
			} catch (InitializationStringEvaluationException e) {
				processException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}

	}

	/**
	 * Push prefix expression.
	 * @param operator 
	 * @since 1.0.0
	 */
	public final void pushPrefix(PrefixOperator operator) {
		try {
			if (ignoreExpression != null || errorOccurred) {
				if (traceOn)
					printTrace("Prefix: \'"+operator+"\'", true); //$NON-NLS-1$ //$NON-NLS-2$
				return;
			}
			
			if (operator == PrefixOperator.PRE_PLUS)
				return;	// Do nothing. "+" doesn't affect the result of the current top expression.
	
			if (traceOn)
				printTrace("Prefix: \'"+operator+"\' ", false); //$NON-NLS-1$ //$NON-NLS-2$
	
			try {
				Object exp = popExpression();
				Class exptype = popExpressionType(false);
				if (!exptype.isPrimitive())
					throwInvalidPrefix(operator, exp);
				
				int primTypeEnum = getEnumForPrimitive(exptype);
				switch (operator.getValue()) {
					case PrefixOperator.PRE_MINUS_VALUE:
						switch (primTypeEnum) {
							case BOOLEAN:
								throwInvalidPrefix(operator, exp);						
							case BYTE:
								exp = new Integer(-((Number) exp).byteValue());
								break;
							case CHAR:
								exp = new Integer(-((Character) exp).charValue());
								break;
							case DOUBLE:
								exp = new Double(-((Number) exp).doubleValue());
								break;
							case FLOAT:
								exp = new Float(-((Number) exp).floatValue());
								break;
							case INT:
								exp = new Integer(-((Number) exp).intValue());
								break;
							case LONG:
								exp = new Long(-((Number) exp).longValue());
								break;
							case SHORT:
								exp = new Integer(-((Number) exp).shortValue());
								break;
						}
						exptype = getPrimitiveType(exp);	// It can actually change the type.				
						break;
						
					case PrefixOperator.PRE_COMPLEMENT_VALUE:
						switch (primTypeEnum) {
							case BOOLEAN:
							case DOUBLE:
							case FLOAT:
								throwInvalidPrefix(operator, exp);						
							case BYTE:
								exp = new Integer(~((Number) exp).byteValue());
								break;
							case CHAR:
								exp = new Integer(~((Character) exp).charValue());
								break;
							case INT:
								exp = new Integer(~((Number) exp).intValue());
								break;
							case LONG:
								exp = new Long(~((Number) exp).longValue());
								break;
							case SHORT:
								exp = new Integer(~((Number) exp).shortValue());
								break;
						}
						exptype = getPrimitiveType(exp);	// It can actually change the type.
						break;
					case PrefixOperator.PRE_NOT_VALUE:
						switch (primTypeEnum) {
							case BOOLEAN:
								exp = !((Boolean) exp).booleanValue() ? Boolean.TRUE : Boolean.FALSE;
								break;
							case BYTE:
							case CHAR:
							case DOUBLE:
							case FLOAT:
							case INT:
							case LONG:
							case SHORT:
								throwInvalidPrefix(operator, exp);						
						}				
						break;
					}
				
				if (traceOn)
					printObjectAndType(exp, exptype);
				pushExpressionValue(exp, exptype);	// Push the result back on the stack.
	
			} catch (IllegalArgumentException e) {
				processSyntaxException(e);
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			} catch (RuntimeException e) {
				processException(e);
			} 
		} finally {
			if (traceOn)
				printTraceEnd();
		}
			
	}
	
	/**
	 * Assign the right expression to the left expression.
	 * @since 1.1.0
	 */
	public final void pushAssignment() {
		if (ignoreExpression != null || errorOccurred) {
			if (traceOn) {
				printTrace("Assignment", true); //$NON-NLS-1$
				printTraceEnd();
			}
			return;
		}
		
		try {
			// KLUDGE: The only reason leftValue/refType are outside of try/finally is because
			// of tracing. pushExpression() does its own trace statements, so we need to end
			// our trace before calling pushExpression. 
			Object leftValue;
			Class refType;
			try {
				if (traceOn)
					printTrace("Assignment: ", false);			 //$NON-NLS-1$	
				// The order on the stack is right then left operand.
				// First the right operand
				Object value = popExpression();
				Class type = popExpressionType(false);

				// Next the left operand, should be a reference.
				VariableReference left = (VariableReference) popExpression(false); // Don't dereference it.
				refType = popExpressionType(false);

				if (traceOn)
					printObjectAndType(left, refType);

				leftValue = left.set(value, type);
			} finally {
				if (traceOn)
					printTraceEnd();
			}
			
			// Now do assignment and return the value to the stack.
			pushExpression(leftValue, refType);	// The type of the result is the type of the reference.

		} catch (IllegalArgumentException e) {
			processException(e);
		} catch (NoExpressionValueException e) {
			processSyntaxException(e);
		} catch (IllegalAccessException e) {
			processException(e);
		} catch (RuntimeException e) {
			processException(e);
		}
			
	}
	
	/**
	 * Assign the expression proxy to the top expression value.
	 * 
	 * @param proxy
	 * 
	 * @since 1.1.0
	 */
	public final void pushAssignment(InternalExpressionProxy proxy) {
		boolean ignore = (ignoreExpression != null || errorOccurred);
		try {
			if (traceOn) {
				printTrace("Assign to Proxy #"+proxy.getProxyID(), ignore); //$NON-NLS-1$
			}
			if (ignore)
				return;
			
			try {
				assignToExpressionProxyFromTopStackEntry(proxy);
				if (traceOn)
					printObjectAndType(proxy.getValue(), proxy.getType());
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			} catch (RuntimeException e) {
				processException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}

	}

	/**
	 * Assign the top stack entry to the new expression proxy and allocate it for callback later.
	 * @param proxy
	 * @throws NoExpressionValueException
	 * 
	 * @since 1.1.0
	 */
	protected void assignToExpressionProxyFromTopStackEntry(InternalExpressionProxy proxy) throws NoExpressionValueException {
		Object value = getExpression(1);
		Class type = getExpressionType(1, true);
		if (value instanceof VariableReference)
			value = ((VariableReference) value).dereference();	// Here we want the final current value.

		proxy.setProxy(value, type);
		allocateExpressionProxy(proxy);
	}

	/**
	 * Allocate an expression proxy. This is used to make an expression proxy known to the processor. The expression proxy must
	 * have been setProxy() at this point. This is used to assign from the top of the stack or to add from outside an evaluated proxy
	 * to be used later by others.
	 * 
	 * @param proxy
	 * 
	 * @since 1.1.0
	 */
	public void allocateExpressionProxy(InternalExpressionProxy proxy) {
		int minSize = proxy.getProxyID()+1;
		if (expressionProxies == null)
			expressionProxies = new ArrayList(minSize+10);	// Allow room to grow ten more.
		else if (expressionProxies.size() < minSize)
			expressionProxies.ensureCapacity(minSize+10);	// Allow room to grow ten more.
		int fill = minSize-expressionProxies.size();	// Number of "null" fill entries needed. Probably shouldn't occur, but to be safe.
		if (fill > 0) {
			while (--fill > 0)
				expressionProxies.add(null);
			expressionProxies.add(proxy);
		} else
			expressionProxies.set(proxy.getProxyID(), proxy);	// Already large enough, replace entry.

	}

	/**
	 * The primitive enums. 
	 * NOTE: Their order must not changed. They are in order of permitted widening.
	 * 
	 */
	protected static final int
		BOOLEAN = 0,
		BYTE = 1,
		SHORT = 2,	
		CHAR = 3,
		INT = 4,
		LONG = 5,
		FLOAT = 6,
		DOUBLE = 7;
		
		
	
	/**
	 * Get the enum constant for the type of primitive passed in.
	 * <p>
	 * This is a helper method for expression processer to get the enum for the primitive type. Since it is a helper method it doesn't
	 * check nor process the exception. It throws it. Callers must handle it as they see fit.

	 * @param primitiveType
	 * @return
	 * @throws IllegalArgumentException if type is not a primitive.
	 * 
	 * @see ExpressionProcesser#BOOLEAN
	 * @since 1.0.0
	 */
	protected final int getEnumForPrimitive(Class primitiveType) throws IllegalArgumentException {
		if (primitiveType == Boolean.TYPE)
			return BOOLEAN;
		else if (primitiveType == Integer.TYPE)
			return INT;
		else if (primitiveType == Byte.TYPE)
			return BYTE;
		else if (primitiveType == Character.TYPE)
			return CHAR;
		else if (primitiveType == Double.TYPE)
			return DOUBLE;
		else if (primitiveType == Float.TYPE)
			return FLOAT;
		else if (primitiveType == Long.TYPE)
			return LONG;
		else if (primitiveType == Short.TYPE)
			return SHORT;
		else
			throw new IllegalArgumentException(primitiveType != null ? primitiveType.getName() : "null"); //$NON-NLS-1$
	}
	
	private void throwInvalidPrefix(PrefixOperator operator, Object exp) throws IllegalArgumentException {
		throw new IllegalArgumentException(MessageFormat.format(InitparserTreeMessages.getString("ExpressionProcesser.InvalidOperandOfPrefixOperator_EXC_"), new Object[] {exp != null ? exp.toString() : null, operator.toString()})); //$NON-NLS-1$
	}		
	
	private static final Object INFIX_IGNORE = "INFIX IGNORE";	// Flag for infix in ingore //$NON-NLS-1$
	private int infixNesting = 0;	// Nesting of infix expressions.
	private int infixIgnoreNestCount = 0;	// When ignoring infix expressions, ignore until this nest count.
	/**
	 * Push the infix expression onto the stack.
	 * @param operator
	 * @param operandType The operator type. Left, right, other.
	 * @since 1.0.0
	 */
	public final void pushInfix(InfixOperator operator, InternalInfixOperandType operandType) {
		try {
			boolean ignore = true;
			try {
				if (errorOccurred) {
					return;
				}
				// Slightly different here in that if an ignored occurred we still need to process at least part of it so that
				// we can get the expression grouping correct.
				if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
					infixNesting++;
				else if (operandType == InternalInfixOperandType.INFIX_LAST_OPERAND) {
					int currentNest = infixNesting--;
					if (ignoreExpression == INFIX_IGNORE && currentNest == infixIgnoreNestCount) {
						// We were ignoring, and it was this expression that was being ignore.
						// We have received the last operand of the nested expression that was being ignored,
						// so we can stop ignoring. But we still leave since the value of the expression is on the
						// top of the stack.
						ignoreExpression = null;
						return;
					}
				}
	
				if (ignoreExpression != null)
					return;
				ignore = false;
			} finally {
				if (traceOn)
					printTrace("Infix: "+operator, ignore); //$NON-NLS-1$
			}
			
			try {
				Object right = null;
				Class rightType = null;
				if (operandType != InternalInfixOperandType.INFIX_LEFT_OPERAND) {
					// We are not the left operand, so the stack has the right on the top, followed by the left.
					right = popExpression();
					rightType = popExpressionType(false);
				} 
				
				Object value = popExpression();
				Class valueType = popExpressionType(false);
	
				switch (operator.getValue()) {
					case InfixOperator.IN_AND_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidBitType(valueType, InfixOperator.IN_AND);
						testValidBitType(rightType, InfixOperator.IN_AND);
						if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, the result will be long.
							value = new Long(getLong(value) & getLong(right));
							valueType = Long.TYPE;
						} else {
							// Else it is int. (even two shorts together produce an int).
							value = new Integer(getInt(value) & getInt(right));
							valueType = Integer.TYPE;
						}
						break;
					case InfixOperator.IN_CONDITIONAL_AND_VALUE:
						// This is tricky.
						// First if this is left type, then just continue.
						// Else if this other or last, then need to make it the new value.
						if (operandType != InternalInfixOperandType.INFIX_LEFT_OPERAND) {
							value = right;
							valueType = rightType;
						}
							
						//If the value is now false, we need to ignore the rest.
						if (valueType != Boolean.TYPE)
							throwInvalidInfix(operator, value);
						if (!((Boolean) value).booleanValue() && operandType != InternalInfixOperandType.INFIX_LAST_OPERAND)
							startInfixIgnore();	// Start ignoring because we know the value of the expression at this point. It is false.
						break;
					case InfixOperator.IN_CONDITIONAL_OR_VALUE:
						// This is tricky.
						// First if this is left type, then just continue.
						// Else if this other or last, then need to make it the new value.
						if (operandType != InternalInfixOperandType.INFIX_LEFT_OPERAND) {
							value = right;
							valueType = rightType;
						}
						
						//If the value is now true, we need to ignore the rest.
						if (valueType != Boolean.TYPE)
							throwInvalidInfix(operator, value);
						if (((Boolean) value).booleanValue() && operandType != InternalInfixOperandType.INFIX_LAST_OPERAND)
							startInfixIgnore(); // Start ignoring because we know the value of the expression at this point. It is true.
						break;
					case InfixOperator.IN_DIVIDE_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidArithmeticType(valueType, InfixOperator.IN_DIVIDE);
						testValidArithmeticType(rightType, InfixOperator.IN_DIVIDE);
						if (valueType == Double.TYPE || rightType == Double.TYPE) {
							// If either side is double, the result will be double.
							value = new Double(getDouble(value) / getDouble(right));
							valueType = Double.TYPE;
						} else if (valueType == Float.TYPE || rightType == Float.TYPE) {
							// If either side is float, the result will be float.
							value = new Float(getFloat(value) / getFloat(right));
							valueType = Float.TYPE;
						} else if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, the result will be long.
							value = new Long(getLong(value) / getLong(right));
							valueType = Long.TYPE;
						} else {
							// Else it will result in an int, even if both sides are short.
							value = new Integer(getInt(value) / getInt(right));
							valueType = Integer.TYPE;
						}
						break;
					case InfixOperator.IN_EQUALS_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						// We should never get extended operator for this, but we'll ignore the possibility.
						if (valueType.isPrimitive() && rightType.isPrimitive()) {
							// Primitives require more testing than just ==. boolean primitives 
							if (valueType == Boolean.TYPE || rightType == Boolean.TYPE) {
								// If either side is a boolean, then the other side needs to be boolean for it to even try to be true.
								if (valueType != Boolean.TYPE || valueType != Boolean.TYPE)
									value = Boolean.FALSE;
								else
									value = (((Boolean) value).booleanValue() == ((Boolean) right).booleanValue()) ? Boolean.TRUE : Boolean.FALSE;
							} else {
								// Now do number tests since not boolean primitive, only numbers are left
								if (valueType == Double.TYPE || rightType == Double.TYPE) {
									// If either side is double, compare as double.
									value = (getDouble(value) == getDouble(right)) ? Boolean.TRUE : Boolean.FALSE;
								} else if (valueType == Float.TYPE || rightType == Float.TYPE) {
									// If either side is float, compare as float.
									value = (getFloat(value) == getFloat(right)) ? Boolean.TRUE : Boolean.FALSE;
								} else if (valueType == Long.TYPE || rightType == Long.TYPE) {
									// If either side is long, the compare as long.
									value = (getLong(value) == getLong(right)) ? Boolean.TRUE : Boolean.FALSE;
								} else {
									// Else it will compare as int, even if both sides are short.
									value = (getInt(value) == getInt(right)) ? Boolean.TRUE : Boolean.FALSE;
								}
							}
						} else if (valueType.isPrimitive() || rightType.isPrimitive())
							value = Boolean.FALSE;	// Can't be true if one side prim and the other isn't
						else {
							// Just do object ==
							value = (value == right) ? Boolean.TRUE : Boolean.FALSE;
						}
						valueType = Boolean.TYPE;	// We know result will be a boolean.
						break;
					case InfixOperator.IN_GREATER_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidArithmeticType(valueType, InfixOperator.IN_GREATER);
						testValidArithmeticType(rightType, InfixOperator.IN_GREATER);
						if (valueType == Double.TYPE || rightType == Double.TYPE) {
							// If either side is double, compare will be double.
							value = (getDouble(value) > getDouble(right)) ? Boolean.TRUE : Boolean.FALSE;
						} else if (valueType == Float.TYPE || rightType == Float.TYPE) {
							// If either side is float, compare will be float.
							value = (getFloat(value) > getFloat(right)) ? Boolean.TRUE : Boolean.FALSE;
						} else if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, compare will be long.
							value = (getLong(value) > getLong(right)) ? Boolean.TRUE : Boolean.FALSE;
						} else {
							// Else compare will be int, even if both sides are short.
							value = (getInt(value) > getInt(right)) ? Boolean.TRUE : Boolean.FALSE;
						}
						valueType = Boolean.TYPE;	// We know result will be a boolean.
						break;
					case InfixOperator.IN_GREATER_EQUALS_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidArithmeticType(valueType, InfixOperator.IN_GREATER_EQUALS);
						testValidArithmeticType(rightType, InfixOperator.IN_GREATER_EQUALS);
						if (valueType == Double.TYPE || rightType == Double.TYPE) {
							// If either side is double, compare will be double.
							value = (getDouble(value) >= getDouble(right)) ? Boolean.TRUE : Boolean.FALSE;
						} else if (valueType == Float.TYPE || rightType == Float.TYPE) {
							// If either side is float, compare will be float.
							value = (getFloat(value) >= getFloat(right)) ? Boolean.TRUE : Boolean.FALSE;
						} else if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, compare will be long.
							value = (getLong(value) >= getLong(right)) ? Boolean.TRUE : Boolean.FALSE;
						} else {
							// Else compare will be int, even if both sides are short.
							value = (getInt(value) >= getInt(right)) ? Boolean.TRUE : Boolean.FALSE;
						}
						valueType = Boolean.TYPE;	// We know result will be a boolean.
						break;
					case InfixOperator.IN_LEFT_SHIFT_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidBitType(valueType, InfixOperator.IN_LEFT_SHIFT);
						testValidBitType(rightType, InfixOperator.IN_LEFT_SHIFT);
						if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, the result will be long.
							value = new Long(getLong(value) << getLong(right));
							valueType = Long.TYPE;
						} else {
							// Else it is int. (even two shorts together produce an int).
							value = new Integer(getInt(value) << getInt(right));
							valueType = Integer.TYPE;
						}
						break;
					case InfixOperator.IN_LESS_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidArithmeticType(valueType, InfixOperator.IN_LESS);
						testValidArithmeticType(rightType, InfixOperator.IN_LESS);
						if (valueType == Double.TYPE || rightType == Double.TYPE) {
							// If either side is double, compare will be double.
							value = (getDouble(value) < getDouble(right)) ? Boolean.TRUE : Boolean.FALSE;
						} else if (valueType == Float.TYPE || rightType == Float.TYPE) {
							// If either side is float, compare will be float.
							value = (getFloat(value) < getFloat(right)) ? Boolean.TRUE : Boolean.FALSE;
						} else if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, compare will be long.
							value = (getLong(value) < getLong(right)) ? Boolean.TRUE : Boolean.FALSE;
						} else {
							// Else compare will be int, even if both sides are short.
							value = (getInt(value) < getInt(right)) ? Boolean.TRUE : Boolean.FALSE;
						}
						valueType = Boolean.TYPE;	// We know result will be a boolean.
						break;
					case InfixOperator.IN_LESS_EQUALS_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidArithmeticType(valueType, InfixOperator.IN_LESS_EQUALS);
						testValidArithmeticType(rightType, InfixOperator.IN_LESS_EQUALS);
						if (valueType == Double.TYPE || rightType == Double.TYPE) {
							// If either side is double, compare will be double.
							value = (getDouble(value) <= getDouble(right)) ? Boolean.TRUE : Boolean.FALSE;
						} else if (valueType == Float.TYPE || rightType == Float.TYPE) {
							// If either side is float, compare will be float.
							value = (getFloat(value) <= getFloat(right)) ? Boolean.TRUE : Boolean.FALSE;
						} else if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, compare will be long.
							value = (getLong(value) <= getLong(right)) ? Boolean.TRUE : Boolean.FALSE;
						} else {
							// Else compare will be int, even if both sides are short.
							value = (getInt(value) <= getInt(right)) ? Boolean.TRUE : Boolean.FALSE;
						}
						valueType = Boolean.TYPE;	// We know result will be a boolean.
						break;
					case InfixOperator.IN_MINUS_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidArithmeticType(valueType, InfixOperator.IN_MINUS);
						testValidArithmeticType(rightType, InfixOperator.IN_MINUS);
						if (valueType == Double.TYPE || rightType == Double.TYPE) {
							// If either side is double, the result will be double.
							value = new Double(getDouble(value) - getDouble(right));
							valueType = Double.TYPE;
						} else if (valueType == Float.TYPE || rightType == Float.TYPE) {
							// If either side is float, the result will be float.
							value = new Float(getFloat(value) - getFloat(right));
							valueType = Float.TYPE;
						} else if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, the result will be long.
							value = new Long(getLong(value) - getLong(right));
							valueType = Long.TYPE;
						} else {
							// Else it will result in an int, even if both sides are short.
							value = new Integer(getInt(value) - getInt(right));
							valueType = Integer.TYPE;
						}
						break;
					case InfixOperator.IN_NOT_EQUALS_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						// We should never get extended operator for this, but we'll ignore the possibility.
						if (valueType.isPrimitive() && rightType.isPrimitive()) {
							// Primitives require more testing than just ==. boolean primitives 
							if (valueType == Boolean.TYPE || rightType == Boolean.TYPE) {
								// If either side is a boolean, then the other side needs to be boolean for it to even try to be true.
								if (valueType != Boolean.TYPE || valueType != Boolean.TYPE)
									value = Boolean.TRUE;
								else
									value = (((Boolean) value).booleanValue() != ((Boolean) right).booleanValue()) ? Boolean.TRUE : Boolean.FALSE;
							} else {
								// Now do number tests since not boolean primitive, only numbers are left
								if (valueType == Double.TYPE || rightType == Double.TYPE) {
									// If either side is double, compare as double.
									value = (getDouble(value) != getDouble(right)) ? Boolean.TRUE : Boolean.FALSE;
								} else if (valueType == Float.TYPE || rightType == Float.TYPE) {
									// If either side is float, compare as float.
									value = (getFloat(value) != getFloat(right)) ? Boolean.TRUE : Boolean.FALSE;
								} else if (valueType == Long.TYPE || rightType == Long.TYPE) {
									// If either side is long, the compare as long.
									value = (getLong(value) != getLong(right)) ? Boolean.TRUE : Boolean.FALSE;
								} else {
									// Else it will compare as int, even if both sides are short.
									value = (getInt(value) != getInt(right)) ? Boolean.TRUE : Boolean.FALSE;
								}
							}
						} else if (valueType.isPrimitive() || rightType.isPrimitive())
							value = Boolean.TRUE;	// Must be true if one side prim and the other isn't
						else {
							// Just do object !=
							value = (value != right) ? Boolean.TRUE : Boolean.FALSE;
						}
						valueType = Boolean.TYPE;	// We know result will be a boolean.
						break;
					case InfixOperator.IN_OR_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidBitType(valueType, InfixOperator.IN_OR);
						testValidBitType(rightType, InfixOperator.IN_OR);
						if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, the result will be long.
							value = new Long(getLong(value) | getLong(right));
							valueType = Long.TYPE;
						} else {
							// Else it is int. (even two shorts together produce an int).
							value = new Integer(getInt(value) | getInt(right));
							valueType = Integer.TYPE;
						}
						break;
					case InfixOperator.IN_PLUS_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND) {
							if (valueType == String.class) {
								// Special. left argument is a string, so we want to store a string buffer instead
								// since we know we will be appending to it. 
								value = new StringBuffer((String) value);
							}	
							break;	// Do nothing with first operand
						}
						
						testValidPlusType(valueType, rightType);
						if (valueType == String.class || rightType == String.class) {
							// Special we have a string on one side. Need to do it as strings instead.
							// We are going to be tricky in that we will store a StringBuffer on the stack (if not last operand)
							// but call it a string.
							StringBuffer sb = null;
							if (valueType == String.class) {
								sb = (StringBuffer) value;	// We know that if the value (left) is string type, we've already converted it to buffer.
							} else {
								// The right is the one that introduces the string, so we change the value over to a string buffer.
								sb = new StringBuffer(((String) right).length()+16);	// We can't put the value in yet, need to get left into it.
								appendToBuffer(sb, value, valueType);	// Put the left value in now
								value = sb;
								valueType = String.class;	// Make it a string class
							}
							appendToBuffer(sb, right, rightType);
							// Now if we are the last operand, we should get rid of the buffer and put a true string back in.
							if (operandType == InternalInfixOperandType.INFIX_LAST_OPERAND)
								value = sb.toString();
						} else if (valueType == Double.TYPE || rightType == Double.TYPE) {
							// If either side is double, the result will be double.
							value = new Double(getDouble(value) + getDouble(right));
							valueType = Double.TYPE;
						} else if (valueType == Float.TYPE || rightType == Float.TYPE) {
							// If either side is float, the result will be float.
							value = new Float(getFloat(value) + getFloat(right));
							valueType = Float.TYPE;
						} else if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, the result will be long.
							value = new Long(getLong(value) + getLong(right));
							valueType = Long.TYPE;
						} else {
							// Else it will result in an int, even if both sides are short.
							value = new Integer(getInt(value) + getInt(right));
							valueType = Integer.TYPE;
						}
						break;
					case InfixOperator.IN_REMAINDER_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidArithmeticType(valueType, InfixOperator.IN_REMAINDER);
						testValidArithmeticType(rightType, InfixOperator.IN_REMAINDER);
						if (valueType == Double.TYPE || rightType == Double.TYPE) {
							// If either side is double, the result will be double.
							value = new Double(getDouble(value) % getDouble(right));
							valueType = Double.TYPE;
						} else if (valueType == Float.TYPE || rightType == Float.TYPE) {
							// If either side is float, the result will be float.
							value = new Float(getFloat(value) % getFloat(right));
							valueType = Float.TYPE;
						} else if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, the result will be long.
							value = new Long(getLong(value) % getLong(right));
							valueType = Long.TYPE;
						} else {
							// Else it will result in an int, even if both sides are short.
							value = new Integer(getInt(value) % getInt(right));
							valueType = Integer.TYPE;
						}
						break;
					case InfixOperator.IN_RIGHT_SHIFT_SIGNED_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidBitType(valueType, InfixOperator.IN_RIGHT_SHIFT_SIGNED);
						testValidBitType(rightType, InfixOperator.IN_RIGHT_SHIFT_SIGNED);
						if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, the result will be long.
							value = new Long(getLong(value) >> getLong(right));
							valueType = Long.TYPE;
						} else {
							// Else it is int. (even two shorts together produce an int).
							value = new Integer(getInt(value) >> getInt(right));
							valueType = Integer.TYPE;
						}
						break;
					case InfixOperator.IN_RIGHT_SHIFT_UNSIGNED_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidBitType(valueType, InfixOperator.IN_RIGHT_SHIFT_UNSIGNED);
						testValidBitType(rightType, InfixOperator.IN_RIGHT_SHIFT_UNSIGNED);
						if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, the result will be long.
							value = new Long(getLong(value) >>> getLong(right));
							valueType = Long.TYPE;
						} else {
							// Else it is int. (even two shorts together produce an int).
							value = new Integer(getInt(value) >>> getInt(right));
							valueType = Integer.TYPE;
						}
						break;
					case InfixOperator.IN_TIMES_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidArithmeticType(valueType, InfixOperator.IN_TIMES);
						testValidArithmeticType(rightType, InfixOperator.IN_TIMES);
						if (valueType == Double.TYPE || rightType == Double.TYPE) {
							// If either side is double, the result will be double.
							value = new Double(getDouble(value) * getDouble(right));
							valueType = Double.TYPE;
						} else if (valueType == Float.TYPE || rightType == Float.TYPE) {
							// If either side is float, the result will be float.
							value = new Float(getFloat(value) * getFloat(right));
							valueType = Float.TYPE;
						} else if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, the result will be long.
							value = new Long(getLong(value) * getLong(right));
							valueType = Long.TYPE;
						} else {
							// Else it will result in an int, even if both sides are short.
							value = new Integer(getInt(value) * getInt(right));
							valueType = Integer.TYPE;
						}
						break;
					case InfixOperator.IN_XOR_VALUE:
						if (operandType == InternalInfixOperandType.INFIX_LEFT_OPERAND)
							break;	// Do nothing with first operand
						
						testValidBitType(valueType, InfixOperator.IN_XOR);
						testValidBitType(rightType, InfixOperator.IN_XOR);
						if (valueType == Long.TYPE || rightType == Long.TYPE) {
							// If either side is long, the result will be long.
							value = new Long(getLong(value) ^ getLong(right));
							valueType = Long.TYPE;
						} else {
							// Else it is int. (even two shorts together produce an int).
							value = new Integer(getInt(value) ^ getInt(right));
							valueType = Integer.TYPE;
						}
						break;
					} 
				
				if (traceOn)
					printObjectAndType(value, valueType);
				pushExpressionValue(value, valueType);	// Push the result back on the stack.
	
			} catch (IllegalArgumentException e) {
				processException(e);
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			} catch (RuntimeException e) {
				processException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
			
	}

	/**
	 * Start ignoring rest of the current infix expression.
	 * 
	 * @since 1.1.0
	 */
	private void startInfixIgnore() {
		ignoreExpression = INFIX_IGNORE;
		infixIgnoreNestCount = infixNesting;	// Ignore until we get back to the current nesting.

	}

	/**
	 * Get int value of the primitive wrapper bean passed in (must be either a <code>Number/code> or <code>Character</code>.
	 * Anything else will cause a class cast error.
	 * <p>
	 * This is a helper method for expression processer to get the int value of the object. Since it is a helper method it doesn't
	 * check nor process the exception. It throws it. Callers must handle it as they see fit.
	 * @param bean
	 * @return the int value of the number/character
	 * @throws ClassCastException
	 * 
	 * @since 1.0.0
	 */
	protected final int getInt(Object bean) throws ClassCastException {
		return (bean instanceof Number) ? ((Number) bean).intValue() : ((Character) bean).charValue();
	}
	
	/**
	 * Get float value of the primitive wrapper bean passed in (must be either a <code>Number/code> or <code>Character</code>.
	 * Anything else will cause a class cast error.
	 * <p>
	 * This is a helper method for expression processer to get the float value of the object. Since it is a helper method it doesn't
	 * check nor process the exception. It throws it. Callers must handle it as they see fit.
	 * @param bean 
	 * @return float value of the Number/character
	 * @throws ClassCastException
	 * @since 1.0.0
	 */
	protected final float getFloat(Object bean) throws ClassCastException {
		return (bean instanceof Number) ? ((Number) bean).floatValue() : ((Character) bean).charValue();
	}

	/**
	 * Get double value of the primitive wrapper bean passed in (must be either a <code>Number/code> or <code>Character</code>.
	 * Anything else will cause a class cast error.
	 * <p>
	 * This is a helper method for expression processer to get the float value of the object. Since it is a helper method it doesn't
	 * check nor process the exception. It throws it. Callers must handle it as they see fit.
	 * 
	 * @param bean
	 * @return double value of the Number/Character.
	 * @throws ClassCastException
	 * @since 1.0.0
	 */
	protected final double getDouble(Object bean) throws ClassCastException {
		return (bean instanceof Number) ? ((Number) bean).doubleValue() : ((Character) bean).charValue();
	}
	
	/**
	 * Get long value of the primitive wrapper bean passed in (must be either a <code>Number/code> or <code>Character</code>.
	 * Anything else will cause a class cast error.
	 * <p>
	 * This is a helper method for expression processer to get the float value of the object. Since it is a helper method it doesn't
	 * check nor process the exception. It throws it. Callers must handle it as they see fit.
	 * 
	 * @param bean
	 * @return
	 * @throws ClassCastException
	 * @since 1.0.0
	 */
	protected final long getLong(Object bean) throws ClassCastException {
		return (bean instanceof Number) ? ((Number) bean).longValue() : ((Character) bean).charValue();
	}
	
	private void throwInvalidInfix(InfixOperator operator, Object value) throws IllegalArgumentException {
		throw new IllegalArgumentException(MessageFormat.format(InitparserTreeMessages.getString("ExpressionProcesser.InvalidOperandOfOperator_EXC_"), new Object[] {value != null ? value.toString() : null, operator.toString()})); //$NON-NLS-1$
	}
	
	private void testValidBitType(Class type, InfixOperator operator) {
		if (!type.isPrimitive() || type == Boolean.TYPE || type == Double.TYPE|| type == Float.TYPE)
			throwInvalidInfix(operator, type);
	}
	
	private void testValidArithmeticType(Class type, InfixOperator operator) {
		if (!type.isPrimitive() || type == Boolean.TYPE)
			throwInvalidInfix(operator, type);
	}

	private void testValidPlusType(Class left, Class right) {
		// Plus is special in that string objects are also valid.
		if (left == String.class || right == String.class)
			return;	// As long as one side is string. Anything is valid.
		// If neither is string, then standard arithmetic test.
		testValidArithmeticType(left, InfixOperator.IN_PLUS);
		testValidArithmeticType(right, InfixOperator.IN_PLUS);
	}
	
	private void appendToBuffer(StringBuffer sb, Object value, Class valueType) {
		if (value == null)
			sb.append((Object)null);
		else if (valueType == String.class)
			sb.append((String) value);
		else if (valueType.isPrimitive()) {
			switch (getEnumForPrimitive(valueType)) {
				case BOOLEAN:
					sb.append(((Boolean) value).booleanValue());
					break;
				case BYTE:
					sb.append(((Number) value).byteValue());
					break;
				case CHAR:
					sb.append(((Character) value).charValue());
					break;
				case DOUBLE:
					sb.append(((Number) value).doubleValue());
					break;
				case FLOAT:
					sb.append(((Number) value).floatValue());
					break;
				case INT:
					sb.append(((Number) value).intValue());
					break;
				case LONG:
					sb.append(((Number) value).longValue());
					break;
				case SHORT:
					sb.append(((Number) value).shortValue());
					break;		
			}
		} else {
			// Just an object.
			sb.append(value);
		}
	}
	
	/**
	 * Push the array access expression.
	 * 
	 * @param indexCount Number of dimensions being accessed
	 * @since 1.0.0
	 */
	public final void pushArrayAccess(int indexCount) {
		boolean ignore = (ignoreExpression != null || errorOccurred);
		
		if (traceOn) {
			printTrace("Array Access["+indexCount+']', ignore); //$NON-NLS-1$
		}
		try {
			if (ignore)
				return;
			
			try {
				// We need to pop off the args. The topmost will be the rightmost index, and the bottom most will be the array itself.
				int[] arguments = new int[indexCount];
				// Fill the arg array in reverse order.
				for(int i=indexCount-1; i >= 0; i--) {
					Object index = popExpression();
					Class indexType = popExpressionType(false);
					if (indexType.isPrimitive() && (indexType == Integer.TYPE || indexType == Short.TYPE || indexType == Character.TYPE || indexType == Byte.TYPE)) {
						arguments[i] = getInt(index);
					} else
						throwClassCast(Integer.TYPE, index);
				}
				
				Object array = popExpression();
				Class arrayType = popExpressionType(false);
				if (arrayType.isArray()) {
					// First figure out how many dimensions are available. Stop when we hit indexcount because we won't be going further.
					int dimcount = 0;
					Class[] componentTypes = new Class[indexCount];	// 
					Class componentType = arrayType;
					while (dimcount < indexCount && componentType.isArray()) {
						componentTypes[dimcount++] = componentType = componentType.getComponentType();
					}
					
					if (dimcount < indexCount)
						throw new IllegalArgumentException(MessageFormat.format(InitparserTreeMessages.getString("ExpressionProcesser.XIsGreaterThanNumberOfDimensionsInArray_EXC_"), new Object[] {new Integer(indexCount), new Integer(dimcount)})); //$NON-NLS-1$
					
					// Now start accessing one index at a time, stop just before the last one. The last one will be turned into an ArrayAccessReference.
					Object value = array;	// Final value, start with full array.
					int pullCount = indexCount-1;
					for(int i=0; i<pullCount; i++) {
						value = Array.get(value, arguments[i]);
					}
					ArrayAccessReference arrayValue = ArrayAccessReference.createArrayAccessReference(value, arguments[pullCount]);
					if (traceOn)
						printObjectAndType(arrayValue, componentTypes[pullCount]);
					pushExpressionValue(arrayValue, componentTypes[pullCount]);
				}  else
					 throw new IllegalArgumentException(MessageFormat.format(InitparserTreeMessages.getString("ExpressionProcesser.NotAnArray_EXC_"), new Object[] {arrayType})); //$NON-NLS-1$
	
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			} catch (RuntimeException e) {
				processException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
	}
	
	/**
	 * Push the array creation request.
	 * 
	 * @param arrayType The type of the array
	 * @param dimensionCount The number of dimensions being initialized. Zero if using an initializer.
	 * @since 1.0.0
	 */
	public final void pushArrayCreation(Class arrayType, int dimensionCount) {
		boolean ignore = (ignoreExpression != null || errorOccurred);
		if (traceOn)
			printTrace("Array Creation: "+arrayType.getName()+'['+dimensionCount+']', ignore); //$NON-NLS-1$
		
		try {
			if (ignore)
				return;
			
			try {
				if (dimensionCount == 0) {
					// The top value is the array itself, from the array initializer.
					// So we do nothing.
				} else {
					// Strip off dimensionCounts from the array type, e.g.
					// ArrayType is int[][][]
					// Dimensioncount is 2
					// Then we need to strip two componenttypes off of the array type
					// wind up with int[]
					// This is necessary because Array.new will add those dimensions back
					// on through the dimension count.
					Class componentType = arrayType;
					for(int i=0; i < dimensionCount && componentType != null; i++)
						componentType = componentType.getComponentType();
					if (componentType == null)
						throw new IllegalArgumentException(MessageFormat.format(InitparserTreeMessages.getString("ExpressionProcesser.ArraytypeHasFewerDimensionsThanRequested_EXC_"), new Object[] {arrayType, new Integer(dimensionCount)})); //$NON-NLS-1$
					
					// We need to pull in the dimension initializers. They are stacked in reverse order.
					int[] dimInit = new int[dimensionCount];
					for(int i=dimensionCount-1; i >= 0; i--) {
						Object index = popExpression();
						Class dimType = popExpressionType(false);
						if (dimType.isPrimitive() && (dimType == Integer.TYPE || dimType == Short.TYPE || dimType == Character.TYPE || dimType == Byte.TYPE)) {
							dimInit[i] = getInt(index);
						} else
							throwClassCast(Integer.TYPE, index);
					}
					
					// Finally create the array.
					Object array = Array.newInstance(componentType, dimInit);
					pushExpressionValue(array, arrayType);
				}
			} catch (RuntimeException e) {
				processException(e);
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
			
	}

	/**
	 * Push the array initializer request.
	 * 
	 * @param arrayType The original type of the array to create.
	 * @param stripCount the count of how many dimensions to strip to get the type needed for this initializer.
	 * @param expressionCount
	 * @since 1.0.0
	 */
	public final void pushArrayInitializer(Class arrayType, int stripCount, int expressionCount) {
		boolean ignore = (ignoreExpression != null || errorOccurred);
		
		if (traceOn)
			printTrace("Initialize Array: "+arrayType.getName()+'{'+expressionCount+'}', ignore); //$NON-NLS-1$
		
		try {
			if (ignore)
				return;
	
			try {
				if (!arrayType.isArray()) {
					// It is not an array type.
					throw new ClassCastException(MessageFormat.format(InitparserTreeMessages.getString("ExpressionProcesser.CannotCastXToY_EXC_"), new Object[] {arrayType, "array"})); //$NON-NLS-1$ //$NON-NLS-2$
				} 
				// Strip off the number of dimensions specified.
				while(stripCount-->0) {
					arrayType = arrayType.getComponentType();
				}
				Object[] dimValues = null;
				if (expressionCount > 0) {
					// We need to pull in the initializers. They are stacked in reverse order.
					dimValues = new Object[expressionCount];
					for (int i = expressionCount - 1; i >= 0; i--) {
						Object dimValue = dimValues[i] = popExpression();
						Class dimType = popExpressionType(false);
						if (arrayType.isPrimitive()) {
							if (dimValue == null || !dimType.isPrimitive())
								throwClassCast(arrayType, dimType);
							// A little trickier. Can assign short to an int, but can't assign long to an int. Widening is permitted.
							if (arrayType != dimType) {
								int compEnum = getEnumForPrimitive(arrayType);
								int dimEnum = getEnumForPrimitive(dimType);
								if (compEnum == BOOLEAN || dimEnum == BOOLEAN)
									throwClassCast(arrayType, dimType);
								int dimValueAsInt = getInt(dimValue);
								switch (compEnum) {
									case BYTE :
										// Can accept byte, short, char, or int as long as value is <= byte max. Can't accept long, double, float at all.
										// Note: This isn't actually true. The max/min test is only valid if the value is a literal, not an expression,
										// however, at this point in time we no longer know this. So we will simply allow it.
										if (dimEnum > INT || dimValueAsInt > Byte.MAX_VALUE || dimValueAsInt < Byte.MIN_VALUE)
											throwClassCast(arrayType, dimType);
										// But need to be changed to appropriate type for the array.set to work.									
										dimValues[i] = new Byte((byte)dimValueAsInt);
										break;
									case SHORT :								
										// Can accept byte, short, char, or int as long as value is <= byte max. Can't accept long, double, float at all.
										// Note: This isn't actually true. The max/min test is only valid if the value is a literal, not an expression,
										// however, at this point in time we no longer know this. So we will simply allow it.
										if (dimEnum > INT || dimValueAsInt > Short.MAX_VALUE || dimValueAsInt < Short.MIN_VALUE)
											throwClassCast(arrayType, dimType);
										// But need to be changed to appropriate type for the array.set to work.									
										dimValues[i] = new Short((short)dimValueAsInt);
										break;
									case CHAR :
										// Can accept byte, short, char, or int as long as value is <= byte max. Can't accept long, double, float at all.
										// Note: This isn't actually true. The max/min test is only valid if the value is a literal, not an expression,
										// however, at this point in time we no longer know this. So we will simply allow it.
										if (dimEnum > INT || dimValueAsInt > Character.MAX_VALUE || dimValueAsInt < Character.MIN_VALUE)
											throwClassCast(arrayType, dimType);
										// But need to be changed to appropriate type for the array.set to work.									
										dimValues[i] = new Character((char)dimValueAsInt);
										break;
									case INT :
										// Can accept byte, short, char, or int. Can't accept long, double, float at all.
										if (dimEnum > INT)
											throwClassCast(arrayType, dimType);
										// But need to be changed to appropriate type for the array.set to work.									
										dimValues[i] = new Integer(dimValueAsInt);
										break;
									case LONG :
										// Can accept byte, short, char, int, or long. Can't accept double, float at all.
										if (dimEnum > LONG)
											throwClassCast(arrayType, dimType);
										// But need to be changed to appropriate type for the array.set to work.									
										dimValues[i] = new Long(getLong(dimValue));
										break;
									case FLOAT :
										// Can accept byte, short, char, int, long, or float. Can't accept double at all.
										if (dimEnum > FLOAT)
											throwClassCast(arrayType, dimType);
										// But need to be changed to appropriate type for the array.set to work.									
										dimValues[i] = new Float(getFloat(dimValue));
										break;
									case DOUBLE :
										// But need to be changed to appropriate type for the array.set to work.									
										dimValues[i] = new Double(getDouble(dimValue));
										break;
	
								}
							}
							// Compatible, so ok.
						} else if (dimType != MethodHelper.NULL_TYPE && !arrayType.isAssignableFrom(dimType)) {
							// If it is NULL_TYPE, then this is a pushed null. This is always assignable to a non-primitive.
							// So we don't enter here in that case. However, a null that was returned from some expression
							// won't have a NULL_TYPE, it will instead have the expected return type. That must be used
							// in the assignment instead. That is because in java it uses the expected type to determine
							// compatibility, not the actual type.
							throwClassCast(arrayType, dimType);
						}
					}
					
				}
				
				// Now we finally create the array.
				Object array = Array.newInstance(arrayType, new int[] {expressionCount});
				for (int i = 0; i < expressionCount; i++) {
					Array.set(array, i, dimValues[i]);
				}
				
				pushExpressionValue(array, array.getClass());	// Adjust to true array type, not the incoming type (which is one dimension too small).
	
			} catch (RuntimeException e) {
				processException(e);
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
			
	}

	/**
	 * Push the class instance creation request.
	 * 
	 * @param type The type to create an instance of
	 * @param argumentCount The number of arguments (which are stored on the stack).	 * @throws NoExpressionValueException
	 * @since 1.0.0
	 */
	public final void pushClassInstanceCreation(Class type, int argumentCount) {
		boolean ignore = (ignoreExpression != null || errorOccurred);
		
		if (traceOn)
			printTrace("Create Class: "+type+" (", ignore); //$NON-NLS-1$ //$NON-NLS-2$
		try {
			if (ignore)
				return;
						
			try {
				// We need to pull in the arguments. They are stacked in reverse order.
				Object value = null;	// The new instance.
				if (argumentCount > 0) {
					Object[]  args = new Object[argumentCount];
					Class[] argTypes = new Class[argumentCount];
					for (int i = argumentCount - 1; i >= 0; i--) {
						args[i] = popExpression();
						argTypes[i] = popExpressionType(false);
					}
					
					// Now we need to find the appropriate constructor.
					Constructor ctor;
					ctor = MethodHelper.findCompatibleConstructor(type, argTypes);
					if (traceOn) {
						System.out.print(ctor);
						System.out.print(')');
					}
					value = ctor.newInstance(args);
				} else {
					// No args, just do default ctor.
					if (traceOn) {
						System.out.print("Default ctor)"); //$NON-NLS-1$
					}
					value = type.newInstance();
				}
				
				pushExpressionValue(value, type);
			} catch (RuntimeException e) {
				processException(e);
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			} catch (InstantiationException e) {
				processException(e);
			} catch (IllegalAccessException e) {
				processException(e);
			} catch (InvocationTargetException e) {
				processException(e);
			} catch (NoSuchMethodException e) {
				processException(e);
			} catch (AmbiguousMethodException e) {
				processException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
			
	}

	/**
	 * Push the field access expression.
	 * @param field String for fieldname, or a java.lang.reflect.Field.
	 * @param fieldIsString <code>true</code> if field is a string name, and not a java.lang.reflect.Field.
	 * @param hasReceiver
	 * 
	 * @since 1.0.0
	 */
	public final void pushFieldAccess(Object field, boolean fieldIsString, boolean hasReceiver) {
		try {
			if (ignoreExpression != null || errorOccurred) {
				if (traceOn)
					printTrace("Field Access", true); //$NON-NLS-1$
				return;
			}
		
			if (traceOn)
				printTrace("Field Access: ", false); //$NON-NLS-1$
			try {
				// Get the receiver off of the stack.
				Object receiver = null;
				Class receiverType = null;
				if (hasReceiver) {
					receiver = popExpression();
					receiverType = popExpressionType(false);
				}
				
				// Find the field.
				Field reflectField = fieldIsString ? receiverType.getField((String) field) : (Field) field;
				// Access the field.
				Object value = FieldAccessReference.createFieldAccessReference(reflectField, receiver);
				Class valueType = reflectField.getType();
				if (traceOn) {
					System.out.print("Field: "); //$NON-NLS-1$
					if (fieldIsString)
						System.out.print("(looked up) "); //$NON-NLS-1$
					System.out.print(reflectField);
					System.out.print(">"); //$NON-NLS-1$
					printObjectAndType(value, valueType);
				}
					
				pushExpressionValue(value, valueType);
			} catch (RuntimeException e) {
				processException(e);
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			} catch (NoSuchFieldException e) {
				processException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
			
	}

	/**
	 * Push the method invocation expression.
	 * @param method
	 * @param methodIsString <code>true</code> if method is a string (so string name) or else it is a java.lang.reflect.Method.
	 * @param hasReceiver
	 * @param argCount
	 * @since 1.0.0
	 */
	public final void pushMethodInvocation(Object method, boolean methodIsString, boolean hasReceiver, int argCount) {
		try {
			if (ignoreExpression != null || errorOccurred) {
				if (traceOn)
					printTrace("Invoke", true); //$NON-NLS-1$
				return;
			}
			
			if (traceOn)
				printTrace("Invoke: ", false); //$NON-NLS-1$
			
			try {
				// We need to pull in the arguments. They are stacked in reverse order.
				Object[]  args = new Object[argCount];
				Class[] argTypes = new Class[argCount];
				for (int i = argCount - 1; i >= 0; i--) {
					args[i] = popExpression();
					argTypes[i] = popExpressionType(false);
				}
				
				// Now get receiver
				Object receiver = null;
				Class receiverType = null;
				if (hasReceiver) {
					receiver = popExpression();
					receiverType = popExpressionType(false);
				}
				
				// Now we need to find the appropriate method. If it is a string then there must be a receiver, otherwise no way to know.
				Method reflectMethod;
				if (methodIsString) {
					reflectMethod = MethodHelper.findCompatibleMethod(receiverType, (String) method, argTypes);
				} else
					reflectMethod = (Method) method;
				
				if (traceOn && reflectMethod != null) {
					System.out.print("Method: "); //$NON-NLS-1$
					if (methodIsString)
						System.out.print("(looked up) "); //$NON-NLS-1$
					System.out.print(reflectMethod);					
				}
				
				Object value = reflectMethod.invoke(receiver, args);
				
				if (traceOn) {
					System.out.print(" returns: "); //$NON-NLS-1$
					printObjectAndType(value, reflectMethod.getReturnType());
				}
				pushExpressionValue(value, reflectMethod.getReturnType());
			} catch (RuntimeException e) {
				processException(e);
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			} catch (IllegalAccessException e) {
				processException(e);
			} catch (InvocationTargetException e) {
				processException(e);
			} catch (NoSuchMethodException e) {
				processException(e);
			} catch (AmbiguousMethodException e) {
				processException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
			
	}

	private static final Object CONDITIONAL_IGNORE = "CONDITIONAL IGNORE";	// Flag for conditional in ingore //$NON-NLS-1$
	private int conditionalNesting = 0;	// Nesting of conditional expressions.
	private int conditionalIgnoreNestCount = 0;	// When ignoring conditional expressions, ignore until this nest count.
	private boolean skipTruePart;

	/**
	 * Push a conditional expression. It can be any clause of the conditional (test, true, or false clause).
	 * @param expressionType
	 * 
	 * @since 1.0.0
	 */
	public final void pushConditional(InternalConditionalOperandType expressionType) {
		try {
			boolean ignore = true;
			try {
				if (errorOccurred)
					return;
				// Slightly different here in that if an ignoring occurred we still need to process at least part of it so that
				// we can get the expression grouping correct.
				switch (expressionType.getValue()) {
					case InternalConditionalOperandType.CONDITIONAL_TEST_VALUE:
						conditionalNesting++;
						break;
					case InternalConditionalOperandType.CONDITIONAL_TRUE_VALUE:
						if (skipTruePart && ignoreExpression == CONDITIONAL_IGNORE && conditionalIgnoreNestCount == conditionalNesting) {
							// stop ignoring, we've ignored the true condition of interest.
							ignoreExpression = null;
							return; // However, leave because since this condition was ignored.
						}
						break;
					case InternalConditionalOperandType.CONDITIONAL_FALSE_VALUE:
						int currentNesting = conditionalNesting--;
						if (ignoreExpression == CONDITIONAL_IGNORE && conditionalIgnoreNestCount == currentNesting) {
							// stop ignoring, we've ignored the false condition of interest.
							ignoreExpression = null;
							return; // However, leave because since this condition was ignored.
						}
				}
	
				if (ignoreExpression != null)
					return;
				ignore = false;
			} finally {
				if (traceOn)
					printTrace("Conditional "+expressionType, ignore); //$NON-NLS-1$
			}
					
			try {
				switch (expressionType.getValue()) {
					case InternalConditionalOperandType.CONDITIONAL_TEST_VALUE:
						Object condition = popExpression();
						Class type = popExpressionType(false);
						if (type != Boolean.TYPE)
							throwClassCast(Boolean.TYPE, condition);
						if (((Boolean) condition).booleanValue()) {
							// Condition was true.
							// Do nothing. Let true condition be processed.
						} else {
							// Condition was false.
							skipTruePart = true;	// Tell the true condition should be ignored.
							ignoreExpression = CONDITIONAL_IGNORE;
							conditionalIgnoreNestCount = conditionalNesting;
						}
						// We don't put anything back on the stack because the condition test is not ever returned.
						// The appropriate true or false condition evaluation will be left on the stack.
						break;
					case InternalConditionalOperandType.CONDITIONAL_TRUE_VALUE:
						skipTruePart = false;	// Tell the false condition should be ignored.
						ignoreExpression = CONDITIONAL_IGNORE;
						conditionalIgnoreNestCount = conditionalNesting;
						break;
					case InternalConditionalOperandType.CONDITIONAL_FALSE_VALUE:
						// There's nothing to do, if it was ignored due to true, we wouldn't of gotton here.
						// If it wasn't ignored, then the result of the false expression is on the stack, which is what it should be.
						break;
				}
			} catch (RuntimeException e) {
				processException(e);
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
	}
	
	private static final Object BLOCK_IGNORE = "BLOCK IGNORE"; //$NON-NLS-1$
	private int[] blocks;	// Stack of block numbers currently evaluating.
	private int topBlock = -1;	// Top block index.
	private int breakBlock = -1;	// Block number we are breaking to.
	
	/**
	 * Push a begin block.
	 * @param blockNumber
	 * 
	 * @since 1.1.0
	 */
	public final void pushBlockBegin(int blockNumber) {
		if (traceOn) {
			printTrace("Begin Block #"+blockNumber, errorOccurred); //$NON-NLS-1$
			indent(true);
		}
		try {
			if (errorOccurred)
				return;
			// We are not checking ignore because this is a structural concept instead of executable expressions, so we need to keep track of these.
			if (blocks == null)
				blocks = new int[10];
			if (++topBlock >= blocks.length) {
				int[] newList = new int[blocks.length*2];
				System.arraycopy(blocks, 0, newList, 0, blocks.length);
				blocks = newList;
			}
			blocks[topBlock] = blockNumber;
		} finally {
			if (traceOn)
				printTraceEnd();
		}
	}
	
	/**
	 * Push a block end. The current block must be the given number, or it is an error.
	 * 
	 * @param blockNumber
	 * 
	 * @since 1.1.0
	 */
	public final void pushBlockEnd(int blockNumber) {
		try {
			if (traceOn) {
				indent(false);
				printTrace("End Block #"+blockNumber, errorOccurred); //$NON-NLS-1$
			}
			if (errorOccurred)
				return;
			// We are not checking ignore because this is a structural concept instead of executable expressions, so we need to keep track of these.
			if (blocks == null || topBlock < 0 || blocks[topBlock] != blockNumber) {
				processSyntaxException(new IllegalStateException(InitparserTreeMessages.getString("ExpressionProcesser.PushBlockEnd.ReceivedEndBlocksOutOfOrder_EXC_"))); //$NON-NLS-1$
			} else {
				topBlock--;
				if (ignoreExpression == BLOCK_IGNORE && blockNumber == breakBlock) {
					ignoreExpression = null;
				}
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}			
	}
	
	/**
	 * Skip all following until we hit the requested block number.
	 * @param blockNumber
	 * 
	 * @since 1.1.0
	 */
	public final void pushBlockBreak(int blockNumber) {
		try {
			if (traceOn)
				printTrace("Break Block #"+blockNumber, errorOccurred); //$NON-NLS-1$
			if (errorOccurred)
				return;
			if (ignoreExpression == null) {
				ignoreExpression = BLOCK_IGNORE;	// Start ignoring expressions until we hit the block number end block.
				breakBlock = blockNumber;
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
	}
	
	private static final Object TRY_THROW_IGNORE = "TRY THROW IGNORE"; //$NON-NLS-1$
	private static final Object TRY_FINAL_IGNORE = "TRY FINAL IGNORE"; //$NON-NLS-1$
	private int[] trys;	// Stack of try numbers currently evaluating.
	// Stack of trys in catch clause (i.e. starting executing a catch/final clause for the try). Corresponds with try from same index in trys. Contains the throwable for the catch.
	// This is used to know we are executing a catch (entry not null) and for the rethrow short-hand to rethrow the same exception within the catch.
	private Throwable[] trysInCatch;	
	private int topTry = -1;	// Top try index.
	private int breakTry = -1;	// Try number we are breaking to.
	private Throwable catchThrowable;	// The throwable to check catches against.
	
	/**
	 * Push a try statement.
	 * @param tryNumber
	 * 
	 * @since 1.1.0
	 */
	public final void pushTryBegin(int tryNumber) {
		try {
			if (traceOn) {
				printTrace("Begin Try #"+tryNumber, errorOccurred); //$NON-NLS-1$
				indent(true);
			}
	
			if (errorOccurred)
				return;
			// We are not checking ignore because this is a structural concept instead of executable expressions, so we need to keep track of these.
			if (trys == null) {
				trys = new int[10];
				trysInCatch = new Throwable[10];
			}
			if (++topTry >= trys.length) {
				int[] newList = new int[trys.length*2];
				System.arraycopy(trys, 0, newList, 0, trys.length);
				trys = newList;
				Throwable[] newCatches = new Throwable[trys.length];
				System.arraycopy(trysInCatch, 0, newCatches, 0, trysInCatch.length);
				trysInCatch = newCatches;
			}
			trys[topTry] = tryNumber;
			trysInCatch[topTry] = null;
		} finally {
			if (traceOn)
				printTraceEnd();
		}
	}

	/**
	 * Throw the top stack entry. It must be an exception.
	 * 
	 * 
	 * @since 1.1.0
	 */
	public final void pushThrowException() {
		try {
			boolean ignore = (ignoreExpression != null || errorOccurred);
			if (traceOn)
				printTrace("Throw exception: ", ignore); //$NON-NLS-1$
			
			if (ignore)
				return;
	
			try {
				Object t = popExpression();
				popExpressionType(false);
				if (traceOn) {
					System.out.print(t);
				}
				throwException((Throwable) t);
			} catch (NoExpressionValueException e) {
				processSyntaxException(e);
			} catch (ClassCastException e) {
				processException(e);
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}			
	}
	
	/**
	 * Throw this exception (means throw through the expression being processed, not throw for this thread).
	 * @param exception
	 * 
	 * @since 1.1.0
	 */
	protected final void throwException(Throwable exception) {
		if (topTry == -1) {
			// There are no tries, so treat this as a syntax error.
			processSyntaxException(exception);
		} else if (trysInCatch[topTry] == null) {
			// We are not in a catch clause of the top try. So do a throw ignore for toptry.
			ignoreExpression = TRY_THROW_IGNORE;
			breakTry = trys[topTry];
			catchThrowable = exception;
		} else {
			// We are in a catch of the top try. So do a throw to finally instead.
			ignoreExpression = TRY_FINAL_IGNORE;
			trysInCatch[topTry] = FINAL_CATCH;
			breakTry = trys[topTry];
			catchThrowable = exception;
		}
	}
	
	/**
	 * Push a catch clause
	 * @param tryNumber
	 * @param exceptionType
	 * @param expressionProxy
	 * 
	 * @since 1.1.0
	 */
	public final void pushTryCatchClause(int tryNumber, Class exceptionType, InternalExpressionProxy expressionProxy) {
		try {
			if (traceOn) {
				indent(false);
				if (expressionProxy == null)
					printTrace("Catch Try #"+tryNumber+" ("+exceptionType+')', errorOccurred); //$NON-NLS-1$ //$NON-NLS-2$
				else
					printTrace("Catch Try #"+tryNumber+" ("+exceptionType+") Return exception in proxy #"+expressionProxy.getProxyID(), errorOccurred); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
				indent(true);
			}
			
			if (errorOccurred)
				return;
			
			// We are not checking ignore because this is a structural concept instead of executable expressions, so we need to keep track of these.
			if (trys == null || topTry < 0 || trys[topTry] != tryNumber) {
				processSyntaxException(new IllegalStateException(InitparserTreeMessages.getString("ExpressionProcesser.PushTryCatchClause.CatchReceivedOutOfOrder_EXC_"))); //$NON-NLS-1$
			} else {
				if (ignoreExpression == null) {
					// Normal flow, no throw in progress, so just ignore now until the finally or end try reached.
					ignoreExpression = TRY_FINAL_IGNORE;
					breakTry = tryNumber;
				} else if (ignoreExpression == TRY_THROW_IGNORE && tryNumber == breakTry) {
					// We are here due to a throw occuring in this try block, see if for us, and if it is, stop ignoring.
					// Else just continue ignoring.
					if (exceptionType.isInstance(catchThrowable)) {
						// For us, so just turn everything back on, except mark that we are in the catch phase.
						ignoreExpression = null;
						trysInCatch[topTry] = catchThrowable; // This is so that we know if we throw again that we should not catch anything.
						breakTry = -1;
						if (expressionProxy != null) {
							expressionProxy.setProxy(catchThrowable, catchThrowable.getClass());
							allocateExpressionProxy(expressionProxy);
						}
						if (traceOn) {
							System.out.print(" Caught: "); //$NON-NLS-1$
							System.out.print(catchThrowable);
						}
						catchThrowable = null;
					}
				}
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}			
	}
	
	// This is used only so that finally clause can indicate it was executing so that end expression knows this.
	private static final Throwable FINAL_CATCH = new RuntimeException();

	/**
	 * Push the try finally clause.
	 * @param tryNumber
	 * 
	 * @since 1.1.0
	 */
	public final void pushTryFinallyClause(int tryNumber) {
		try {
			if (traceOn) {
				indent(false);
				printTrace("Finally Try #"+tryNumber, errorOccurred); //$NON-NLS-1$
				indent(true);
			}
			if (errorOccurred)
				return;
			// We are not checking ignore because this is a structural concept instead of executable expressions, so we need to keep track of these.
			if (trys == null || topTry < 0 || trys[topTry] != tryNumber) {
				processSyntaxException(new IllegalStateException(InitparserTreeMessages.getString("ExpressionProcesser.PushTryFinallyClause.FinallyReceivedOutOfOrder_EXC_"))); //$NON-NLS-1$
			} else {
				if (tryNumber == breakTry && (ignoreExpression == TRY_THROW_IGNORE || ignoreExpression == TRY_FINAL_IGNORE)) {
					// We are here due to a throw occuring in this try block or a catch was reached (in which case all intervening catch's were ignored).
					// Now do a normal execution. If we are here due to a throw that wasn't cleared (either no catch or another throw occured within the catch)
					// then we leave it uncleared so that try/end may rethrow it.
					ignoreExpression = null;
					trysInCatch[topTry] = FINAL_CATCH; // We are in the finally clause of a exception being thrown within this try.
					breakTry = -1;
					if (traceOn)
						System.out.print(" Executing finally."); //$NON-NLS-1$
				}
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}			
	}
	
	/**
	 * Rethrow the caught exception. This is a shortcut for:
	 * } catch (Exception e) {
	 *   ... do stuff ...
	 *   throw e;
	 * }
	 * @param tryNumber
	 * 
	 * @since 1.1.0
	 */
	public final void pushTryRethrow(int tryNumber) {
		if (traceOn)
			printTrace("Rethrow Try #"+tryNumber, errorOccurred  || ignoreExpression != null); //$NON-NLS-1$
		
		try {
			if (errorOccurred)
				return;
			// We are not checking ignore because we need to make sure this is not called out of order.
			if (trys == null || topTry < 0 || trys[topTry] != tryNumber) {
				processSyntaxException(new IllegalStateException(InitparserTreeMessages.getString("ExpressionProcesser.PushTryRethrow.RethrowReceivedOutOfOrder_EXC_"))); //$NON-NLS-1$
			} else if (ignoreExpression == null) {
				if (trysInCatch[topTry] == null || trysInCatch[topTry] == FINAL_CATCH)
					processSyntaxException(new IllegalStateException(InitparserTreeMessages.getString("ExpressionProcesser.PushTryRethrow.RetryReceivedOutOfExecutingCatchClause_EXC_"))); //$NON-NLS-1$
				else {
					throwException(trysInCatch[topTry]);
				}
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}		
	}
	
	public final void pushTryEnd(int tryNumber) {
		if (traceOn) {
			indent(false);
			printTrace("End Try #"+tryNumber, errorOccurred); //$NON-NLS-1$
		}
		try {
			if (errorOccurred)
				return;
			// We are not checking ignore because this is a structural concept instead of executable expressions, so we need to keep track of these.
			if (trys == null || topTry < 0 || trys[topTry] != tryNumber) {
				processSyntaxException(new IllegalStateException(InitparserTreeMessages.getString("ExpressionProcesser.PushTryEnd.TryEndReceivedOutOfOrder_EXC_"))); //$NON-NLS-1$
			} else {
				boolean inCatch = trysInCatch[topTry] != null;
				trysInCatch[topTry] = null;
				topTry--;
				if (inCatch || (tryNumber == breakTry && (ignoreExpression == TRY_THROW_IGNORE || ignoreExpression == TRY_FINAL_IGNORE))) {
					// We are here due to a throw or normal flow through a catch. Either way if there is a throwable still pending, we rethrow.
					ignoreExpression = null;
					breakTry = -1;
					if (catchThrowable != null)
						throwException(catchThrowable);
				} 
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}			
	}
	
	/**
	 * Class used to save the state at time of mark. It will
	 * be used to restore state if error.
	 * 
	 * @since 1.1.0
	 */
	protected class SaveState {
		public int markID;
		
		// Block state
		public int topBlock;
		public int breakBlock;
		
		// Try state
		public int topTry;
		public int breakTry;
		public Throwable catchThrowable;
		
		// Error state
		public boolean errorOccurred;
		public boolean novalueException;
		public Throwable exception;
		public Object ignoreExpression;
		
		// Expression stack state
		public int expressionStackPos;
		
		// If/else state
		public int ifElseNesting;
		public int ifElseIgnoreNestCount;
		public boolean ifElseSkipTruePart;
		
		// Other
		public int indent;
		public int expressionProxyPos;
		
		/**
		 * Construct and save the state.
		 * 
		 * @param markNumber
		 * 
		 * @since 1.1.0
		 */
		public SaveState(int markID) {
			this.markID = markID;
			
			ExpressionProcesser ep = ExpressionProcesser.this;
			this.topBlock = ep.topBlock;
			this.breakBlock = ep.breakBlock;
			
			this.topTry = ep.topTry;
			this.breakTry = ep.breakTry;
			this.catchThrowable = ep.catchThrowable;
			
			this.errorOccurred = ep.errorOccurred;
			this.novalueException = ep.novalueException;
			this.exception = ep.exception;
			this.ignoreExpression = ep.ignoreExpression;
			
			this.expressionStackPos = expressionStack.size()-1;
			
			this.ifElseNesting = ep.ifElseNesting;
			this.ifElseIgnoreNestCount = ep.ifElseIgnoreNestCount;
			this.ifElseSkipTruePart = ep.ifElseSkipTruePart;
			
			this.indent = ep.indent;
			this.expressionProxyPos = expressionProxies != null ? expressionProxies.size()-1 : -1;
		}
		
		/**
		 * Restore the state.
		 * 
		 * 
		 * @since 1.1.0
		 */
		public void restoreState() {
			ExpressionProcesser ep = ExpressionProcesser.this;
			ep.topBlock = this.topBlock;
			ep.breakBlock = this.breakBlock;
			
			ep.topTry = this.topTry;
			ep.breakTry = this.breakTry;
			ep.catchThrowable = this.catchThrowable;
			if (trysInCatch != null) {
				for (int i = topTry + 1; i < ep.trysInCatch.length; i++) {
					ep.trysInCatch[i] = null;
				}
			}
			
			ep.errorOccurred = this.errorOccurred;
			ep.novalueException = ep.novalueException;
			ep.exception = this.exception;
			ep.ignoreExpression = this.ignoreExpression;
			
			// Pop stack down to saved state.
			for (int i = expressionStack.size()-1; i > this.expressionStackPos; i--) {
				expressionStack.remove(i);
				expressionTypeStack.remove(i);
			}
			
			ep.ifElseNesting = this.ifElseNesting;
			ep.ifElseIgnoreNestCount = this.ifElseIgnoreNestCount;
			ep.ifElseSkipTruePart = this.ifElseSkipTruePart;
			
			ep.indent = this.indent;
			
			if (expressionProxies != null) {
				for (int i = expressionProxies.size() - 1; i > this.expressionProxyPos; i--) {
					expressionProxies.remove(i);
				}
			}
			
			// These settings can't cross mark boundaries, so reset them to not set. This is in case we were in this state somewhere
			// in the mark when the restore occurred.
			ep.conditionalIgnoreNestCount = 0;
			ep.conditionalNesting = 0;
			ep.skipTruePart = false;
			
			ep.infixIgnoreNestCount = 0;
			ep.infixNesting = 0;
		}
	}
	
	/**
	 * Create the save state with the given id.
	 * @param markID
	 * @return
	 * 
	 * @since 1.1.0
	 */
	protected SaveState createSaveState(int markID) {
		return new SaveState(markID);
	}
	
	/**
	 * Push the start of a mark.
	 * @param markNumber
	 * 
	 * @since 1.1.0
	 */
	public final void pushMark(int markNumber) {
		if (traceOn)
			printTrace("Mark#"+markNumber, false); //$NON-NLS-1$
		
		if (saveStates == null)
			saveStates = new ArrayList();
		saveStates.add(createSaveState(markNumber));
		
		if (traceOn)
			printTraceEnd();
	}
	
	/**
	 * Push the end mark. If there is no error, it will simply
	 * remove it and all save states in the map after it. If there
	 * is an error it will do this plus it will restore the state.
	 * <p>
	 * It is assumed that the calls are coming in correct order from
	 * the server so we won't check validity.
	 * 
	 * @param markID
	 * @param restore
	 * 
	 * @since 1.1.0
	 */
	public final void pushEndmark(int markID, boolean restore) {
		if (traceOn)
			printTrace("End Mark#"+markID+" Restored="+restore, false); //$NON-NLS-1$ //$NON-NLS-2$
		
		try {
			if (saveStates != null) {
				// Start from the end (since that is where it most likely will be) and start
				// search, removing the end one until we reach the markID.
				for (int i = saveStates.size() - 1; i >= 0; i--) {
					SaveState state = (SaveState) saveStates.remove(i);
					if (state.markID == markID) {
						// We found it.
						if (restore)
							state.restoreState();
						return;
					}
				}
				// But to be safe, if we got here, this is bad. We tried restore a mark we didn't have.
				processSyntaxException(new IllegalStateException(MessageFormat.format(InitparserTreeMessages.getString("ExpressionProcesser.PushEndmark.EndMarkOnNonExistingID_EXC_"), new Object[]{new Integer(markID)}))); //$NON-NLS-1$
			}
		} finally {
			if (traceOn)
				printTraceEnd();
		}
	}

}