/* CompareBinaryOperator 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;

public class CompareBinaryOperator extends Operator {
    boolean allowsNaN = false;
    Type compareType;

    public CompareBinaryOperator(Type type, int op) {
        super(Type.tBoolean, op);
	compareType = type;
	initOperands(2);
    }

    public CompareBinaryOperator(Type type, int op, boolean allowsNaN) {
        super(Type.tBoolean, op);
	compareType = type;
	this.allowsNaN = allowsNaN;
	initOperands(2);
    }

    public int getPriority() {
        switch (getOperatorIndex()) {
        case 26:
        case 27:
            return 500;
        case 28:
        case 29:
        case 30:
        case 31: 
            return 550;
        }
        throw new RuntimeException("Illegal operator");
    }

    public Type getCompareType() {
	return compareType;
    }

    public void updateSubTypes() {
	subExpressions[0].setType(Type.tSubType(compareType));
	subExpressions[1].setType(Type.tSubType(compareType));
    }

    public void updateType() {
	Type leftType  = Type.tSuperType(subExpressions[0].getType());
	Type rightType = Type.tSuperType(subExpressions[1].getType());
	compareType = compareType
	    .intersection(leftType).intersection(rightType);
	subExpressions[0].setType(Type.tSubType(rightType));
	subExpressions[1].setType(Type.tSubType(leftType));
	/* propagate hints? XXX */
    }

    public Expression negate() {
	if (!allowsNaN || getOperatorIndex() <= NOTEQUALS_OP) {
            setOperatorIndex(getOperatorIndex() ^ 1);
            return this;
        } 
        return super.negate();
    }

    public boolean opEquals(Operator o) {
	return (o instanceof CompareBinaryOperator)
	    && o.operatorIndex == operatorIndex;
    }

    public void dumpExpression(TabbedPrintWriter writer)
	throws java.io.IOException {
	subExpressions[0].dumpExpression(writer, getPriority()+1);
	writer.breakOp();
	writer.print(getOperatorString());
	subExpressions[1].dumpExpression(writer, getPriority()+1);
    }
}