001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 *
017 */
018package org.apache.bcel.generic;
019
020/**
021 * DCONST - Push 0.0 or 1.0, other values cause an exception
022 *
023 * <PRE>
024 * Stack: ... -&gt; ...,
025 * </PRE>
026 *
027 */
028public class DCONST extends Instruction implements ConstantPushInstruction {
029
030    private double value;
031
032    /**
033     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
034     */
035    DCONST() {
036    }
037
038    public DCONST(final double f) {
039        super(org.apache.bcel.Const.DCONST_0, (short) 1);
040        if (f == 0.0) {
041            super.setOpcode(org.apache.bcel.Const.DCONST_0);
042        } else if (f == 1.0) {
043            super.setOpcode(org.apache.bcel.Const.DCONST_1);
044        } else {
045            throw new ClassGenException("DCONST can be used only for 0.0 and 1.0: " + f);
046        }
047        value = f;
048    }
049
050    /**
051     * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
052     * methods according to the class hierarchy in descending order, i.e., the most specific visitXXX() call comes last.
053     *
054     * @param v Visitor object
055     */
056    @Override
057    public void accept(final Visitor v) {
058        v.visitPushInstruction(this);
059        v.visitStackProducer(this);
060        v.visitTypedInstruction(this);
061        v.visitConstantPushInstruction(this);
062        v.visitDCONST(this);
063    }
064
065    /**
066     * @return Type.DOUBLE
067     */
068    @Override
069    public Type getType(final ConstantPoolGen cp) {
070        return Type.DOUBLE;
071    }
072
073    @Override
074    public Number getValue() {
075        return Double.valueOf(value);
076    }
077}