/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
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 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
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 *    any, must include the following acknowlegement:  
 *       "This product includes software developed by the 
 *        Apache Software Foundation (http://www.apache.org/)."
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 * ====================================================================
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 * This software consists of voluntary contributions made by many
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package org.apache.commons.el;

/**
 *
 * <p>An expression representing a boolean literal value
 * 
 * @author Nathan Abramson - Art Technology Group
 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: luehe $
 **/

public class BooleanLiteral
  extends Literal
{
  //-------------------------------------
  // Member variables
  //-------------------------------------

  public static final BooleanLiteral TRUE = new BooleanLiteral ("true");
  public static final BooleanLiteral FALSE = new BooleanLiteral ("false");

  //-------------------------------------
  /**
   *
   * Constructor
   **/
  public BooleanLiteral (String pToken)
  {
    super (getValueFromToken (pToken));
  }

  //-------------------------------------
  /**
   *
   * Parses the given token into the literal value
   **/
  static Object getValueFromToken (String pToken)
  {
    return
      ("true".equals (pToken)) ?
      Boolean.TRUE :
      Boolean.FALSE;
  }

  //-------------------------------------
  // Expression methods
  //-------------------------------------
  /**
   *
   * Returns the expression in the expression language syntax
   **/
  public String getExpressionString ()
  {
    return (getValue () == Boolean.TRUE) ? "true" : "false";
  }

  //-------------------------------------
}