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    1   /*
    2    * Copyright 2002-2006 The Apache Software Foundation.
    3    *
    4    * Licensed under the Apache License, Version 2.0 (the "License");
    5    * you may not use this file except in compliance with the License.
    6    * You may obtain a copy of the License at
    7    *
    8    *      http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  package org.apache.commons.jexl.parser;
    17
    18  import java.math.BigDecimal;
    19  import java.math.BigInteger;
    20
    21  import org.apache.commons.jexl.JexlContext;
    22
    23  /***
    24   * - (unary minus).
    25   *
    26   * @author <a href="mailto:mhw@kremvax.net">Mark H. Wilkinson</a>
    27   * @version $Id: ASTUnaryMinusNode.java 398325 2006-04-30 12:34:29Z dion $
    28   */
    29  public class ASTUnaryMinusNode extends SimpleNode {
    30      /***
    31       * Create the node given an id.
    32       *
    33       * @param id node id.
    34       */
    35      public ASTUnaryMinusNode(int id) {
    36          super(id);
    37      }
    38
    39      /***
    40       * Create a node with the given parser and id.
    41       *
    42       * @param p a parser.
    43       * @param id node id.
    44       */
    45      public ASTUnaryMinusNode(Parser p, int id) {
    46          super(p, id);
    47      }
    48
    49      /*** {@inheritDoc} */
    50      public Object jjtAccept(ParserVisitor visitor, Object data) {
    51          return visitor.visit(this, data);
    52      }
    53
    54      /*** {@inheritDoc} */
    55      public Object value(JexlContext jc) throws Exception {
    56          Object val = ((SimpleNode) jjtGetChild(0)).value(jc);
    57
    58          if (val instanceof Byte) {
    59              byte valueAsByte = ((Byte) val).byteValue();
    60              return new Byte((byte) -valueAsByte);
    61          } else if (val instanceof Short) {
    62              short valueAsShort = ((Short) val).shortValue();
    63              return new Short((short) -valueAsShort);
    64          } else if (val instanceof Integer) {
    65              int valueAsInt = ((Integer) val).intValue();
    66              return new Integer(-valueAsInt);
    67          } else if (val instanceof Long) {
    68              long valueAsLong = ((Long) val).longValue();
    69              return new Long(-valueAsLong);
    70          } else if (val instanceof Float) {
    71              float valueAsFloat = ((Float) val).floatValue();
    72              return new Float(-valueAsFloat);
    73          } else if (val instanceof Double) {
    74              double valueAsDouble = ((Double) val).doubleValue();
    75              return new Double(-valueAsDouble);
    76          } else if (val instanceof BigDecimal) {
    77              BigDecimal valueAsBigD = (BigDecimal) val;
    78              return valueAsBigD.negate();
    79          } else if (val instanceof BigInteger) {
    80              BigInteger valueAsBigI = (BigInteger) val;
    81              return valueAsBigI.negate();
    82          }
    83          throw new Exception("expression not a number");
    84      }
    85  }