shift.java :  » Scripting » Pnuts » org » pnuts » lib » Java Open Source

/*
 * @(#)shift.java 1.2 04/12/06
 *
 * Copyright (c) 1997-2004 Sun Microsystems, Inc. All Rights Reserved.
 *
 * See the file "LICENSE.txt" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */
package org.pnuts.lib;

import pnuts.lang.*;
import java.util.*;

/*
 * function shift(linkedList)
 */
public class shift extends PnutsFunction {

  public shift(){
    super("shift");
  }

  public boolean defined(int nargs){
    return nargs == 1;
  }

  protected Object exec(Object[] args, Context context){
    if (args.length != 1){
      undefined(args, context);
      return null;
    }
    return ((LinkedList)args[0]).removeFirst();
  }

  public String toString(){
    return "function shift(linkedList)";
  }
}