/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package net.sourceforge.phpdt.internal.compiler.ast;

import net.sourceforge.phpdt.internal.compiler.ASTVisitor;
import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;

public class PrefixExpression extends CompoundAssignment {

	/**
	 * PrefixExpression constructor comment.
	 * 
	 * @param l
	 *            net.sourceforge.phpdt.internal.compiler.ast.Expression
	 * @param r
	 *            net.sourceforge.phpdt.internal.compiler.ast.Expression
	 * @param op
	 *            int
	 */
	public PrefixExpression(Expression l, Expression e, int op, int pos) {

		super(l, e, op, l.sourceEnd);
		this.sourceStart = pos;
		this.sourceEnd = l.sourceEnd;
	}

	public String operatorToString() {

		switch (operator) {
		case PLUS:
			return "++"; //$NON-NLS-1$
		case MINUS:
			return "--"; //$NON-NLS-1$
		}
		return "unknown operator"; //$NON-NLS-1$
	}

	public boolean restrainUsageToNumericTypes() {

		return true;
	}

	public String toStringExpressionNoParenthesis() {

		return operatorToString() + " " + lhs.toStringExpression(); //$NON-NLS-1$

	}

	public void traverse(ASTVisitor visitor, BlockScope scope) {

		if (visitor.visit(this, scope)) {
			lhs.traverse(visitor, scope);
		}
		visitor.endVisit(this, scope);
	}
}