/*
 * Copyright (C) 2010 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.clearsilver.jsilver.functions.operators;

import com.google.clearsilver.jsilver.functions.NonEscapingFunction;
import com.google.clearsilver.jsilver.values.Value;
import static com.google.clearsilver.jsilver.values.Value.literalConstant;

/**
 * X - Y.
 */
public class SubtractFunction extends NonEscapingFunction {

  public Value execute(Value... args) {
    if (args.length == 1) {
      Value value = args[0];
      return literalConstant(0 - value.asNumber(), value);
    } else {
      Value left = args[0];
      Value right = args[1];
      return literalConstant(left.asNumber() - right.asNumber(), left, right);
    }
  }

}