package expression.exceptions;

import expression.AbstractBinaryOperation;
import expression.AbstractExpression;
import expression.OverflowException;

import java.math.BigDecimal;
import java.math.BigInteger;

/**
 * @author Doschennikov Nikita (me@fymio.us)
 */
public class CheckedSubtract extends AbstractBinaryOperation {
    public CheckedSubtract(AbstractExpression l, AbstractExpression r) { super(l, r); }

    @Override protected String  getOperator()  { return "-"; }
    @Override protected int     getPriority()  { return 1; }
    @Override protected boolean isRightAssoc() { return true; }

    @Override
    protected int applyInt(int a, int b) {
        int result = a - b;
        if (((a ^ b) & (a ^ result)) < 0) {
            throw new OverflowException("subtraction");
        }
        return result;
    }

    @Override protected BigInteger applyBi(BigInteger a, BigInteger b) { return a.subtract(b); }
    @Override protected BigDecimal applyBd(BigDecimal a, BigDecimal b) { return a.subtract(b); }
}