/*******************************************************************************
 * Copyright (c) 2017
 *
 * 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 smile.symbolic.internal;

/**
 * @author Ernest DeFoy
 */
public class Constant extends Expression {

    double value;

    public Constant(double value) {

        this.value = value;
    }

    @Override
    public Expression derive() {

        return new Constant(0);
    }

    @Override
    public Constant reduce() {

        return this;
    }

    @Override
    public String getType() {

        // int type
        if ((value == Math.floor(value)) && !Double.isInfinite(value)) {
            return String.valueOf((int)value);
        }

        return String.valueOf(value);
    }

    public double getValue() {
        return value;
    }

    @Override
    public Expression getLeftChild() {
        return null;
    }

    @Override
    public Expression getRightChild() {
        return null;
    }
}