content: /*******************************************************************************
   * Copyright (c) 2009-2011 Luaj.org. All rights reserved.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   * 
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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   ******************************************************************************/
  package org.luaj.vm2;
  
  /** 
   * Base class for functions implemented in Java. 
   * <p>
   * Direct subclass include {@link LibFunction} which is the base class for 
   * all built-in library functions coded in Java, 
   * and {@link LuaClosure}, which represents a lua closure 
   * whose bytecode is interpreted when the function is invoked.    
   * @see LuaValue
   * @see LibFunction
   * @see LuaClosure
   */
  abstract
  public class LuaFunction extends LuaValue {
  	
  	/** Shared static metatable for all functions and closures. */
  	public static LuaValue s_metatable;
  
  	public int type() {
  		return TFUNCTION;
  	}
  	
  	public String typename() {
  		return "function";
  	}
  	
  	public boolean isfunction() {
  		return true;
  	}
  
  	public LuaFunction checkfunction()  {
  		return this;
  	}
  	
  	public LuaFunction optfunction(LuaFunction defval) {
  		return this; 
  	}
  
  	public LuaValue getmetatable() { 
  		return s_metatable; 
  	}
  
  	public String tojstring() {
  		return "function: " + classnamestub();
  	}
  
  	public LuaString strvalue() {
  		return valueOf(tojstring());
  	}
  
  	/** Return the last part of the class name, to be used as a function name in tojstring and elsewhere. 
  	 * @return String naming the last part of the class name after the last dot (.) or dollar sign ($).
  	 */
  	public String classnamestub() {
  		String s = getClass().getName();
  		return s.substring(Math.max(s.lastIndexOf('.'),s.lastIndexOf('$'))+1);
  	}
  	
  	/** Return a human-readable name for this function.  Returns the last part of the class name by default.
  	 * Is overridden by LuaClosure to return the source file and line, and by LibFunctions to return the name.
  	 * @return common name for this function.  */
  	public String name() {
  		return classnamestub();
  	}
  }
  