/* NopOperator Copyright (C) 1998-2002 Jochen Hoenicke.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; see the file COPYING.LESSER.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * $Id$
 */

package net.sf.jode.expr;
import net.sf.jode.type.Type;
import net.sf.jode.decompiler.TabbedPrintWriter;

/**
 * A NopOperator takes one arguments and returns it again.  It is used
 * as placeholder when the real operator is not yet known (e.g. in
 * SwitchBlock, but also in every other Operator).
 *
 * A Nop operator doesn't have subExpressions; getSubExpressions() simply
 * returns zero.
 *
 * @author Jochen Hoenicke */
public class NopOperator extends Expression {
    public NopOperator(Type type) {
	super(type);
    }

    public int getFreeOperandCount() {
	return 1;
    }

    public int getPriority() {
        return 1000;
    }

    public void updateSubTypes() {
    }
    public void updateType() {
    }

    public Expression addOperand(Expression op) {
	op.setType(type);
	op.parent = parent;
	return op;
    }

    public boolean isConstant() {
	return false;
    }

    public boolean equals(Object o) {
	return (o instanceof NopOperator);
    }

    public Expression simplify() {
	return this;
    }

    public void dumpExpression(TabbedPrintWriter writer)
	throws java.io.IOException {
	writer.print("POP");
    }
}