BinaryFunction.java

/**
 *  Copyright (C) 2010 dennis zhuang (killme2008@gmail.com)
 *
 *  This library 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 2.1 of the License, or
 *  (at your option) any later version.
 *
 *  This library 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 **/
package com.googlecode.aviator.runtime.function.system;

import java.util.Map;

import com.googlecode.aviator.exception.ExpressionRuntimeException;
import com.googlecode.aviator.lexer.token.OperatorType;
import com.googlecode.aviator.runtime.function.AbstractFunction;
import com.googlecode.aviator.runtime.type.AviatorObject;


/**
 * Binary function,includes +,-,*,/,%,!
 * 
 * @author dennis
 * 
 */
public class BinaryFunction extends AbstractFunction {
    private final OperatorType opType;


    public BinaryFunction(OperatorType opType) {
        super();
        this.opType = opType;
    }


    public String getName() {
        return this.opType.getToken();
    }


    public OperatorType getOpType() {
        return this.opType;
    }


    @Override
    public AviatorObject call(Map<String, Object> env, AviatorObject arg1, AviatorObject arg2) {
        AviatorObject left = arg1;
        AviatorObject right = arg2;
        switch (this.opType) {
        case ADD:
            return left.add(right, env);
        case SUB:
            return left.sub(right, env);
        case MULT:
            return left.mult(right, env);
        case DIV:
            return left.div(right, env);
        case MOD:
            return left.mod(right, env);
        case NOT:
        case NEG:
            return this.throwArity(2);
        default:
            throw new ExpressionRuntimeException("Invalid binary operator");
        }
    }


    @Override
    public AviatorObject call(Map<String, Object> env, AviatorObject arg1) {
        AviatorObject left = arg1;
        switch (this.opType) {
        case ADD:
        case SUB:
        case MULT:
        case DIV:
        case MOD:
            return this.throwArity(1);
        case NOT:
            return left.not(env);
        case NEG:
            return left.neg(env);
        default:
            throw new ExpressionRuntimeException("Invalid binary operator");

        }
    }

}