mnj/lua/LuaFunction.java

   1 /*  $Header: //info.ravenbrook.com/project/jili/version/1.1/code/mnj/lua/LuaFunction.java#1 $
   2  * Copyright (c) 2006 Nokia Corporation and/or its subsidiary(-ies).
   3  * All rights reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining
   6  * a copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sublicense, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject
  11  * to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be
  14  * included in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  19  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
  20  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
  21  * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 package mnj.lua;
  26
  27 /**
  28  * Models a Lua function.
  29  * Note that whilst the class is public, its constructors are not.
  30  * Functions are created by loading Lua chunks (in source or binary
  31  * form) or executing Lua code which defines functions (and, for
  32  * example, places them in the global table).  {@link
  33  * Lua#load(InputStream, String) Lua.load} is used
  34  * to load a Lua chunk (it returns a <code>LuaFunction</code>),
  35  * and {@link Lua#call Lua.call} is used to call a function.
  36  */
  37 public final class LuaFunction
  38 {
  39   private UpVal[] upval;
  40   private LuaTable env;
  41   private Proto p;
  42
  43   /**
  44    * Constructs an instance from a triple of {Proto, upvalues,
  45    * environment}.  Deliberately not public, See {@link
  46    * Lua#load(InputStream, String) Lua.load} for
  47    * public construction.  All arguments are referenced from the
  48    * instance.  The <code>upval</code> array must have exactly the same
  49    * number of elements as the number of upvalues in <code>proto</code>
  50    * (the value of the <code>nups</code> parameter in the
  51    * <code>Proto</code> constructor).
  52    *
  53    * @param proto  A Proto object.
  54    * @param upval  Array of upvalues.
  55    * @param env    The function's environment.
  56    * @throws NullPointerException if any arguments are null.
  57    * @throws IllegalArgumentsException if upval.length is wrong.
  58    */
  59   LuaFunction(Proto proto, UpVal[] upval, LuaTable env)
  60   {
  61     if (null == proto || null == upval || null == env)
  62     {
  63       throw new NullPointerException();
  64     }
  65     if (upval.length != proto.nups())
  66     {
  67       throw new IllegalArgumentException();
  68     }
  69
  70     this.p = proto;
  71     this.upval = upval;
  72     this.env = env;
  73   }
  74
  75   /** Get nth UpVal. */
  76   UpVal upVal(int n)
  77   {
  78     return upval[n];
  79   }
  80
  81   /** Get the Proto object. */
  82   Proto proto()
  83   {
  84     return p;
  85   }
  86
  87   /** Getter for environment. */
  88   LuaTable getEnv()
  89   {
  90     return env;
  91   }
  92   /** Setter for environment. */
  93   void setEnv(LuaTable env)
  94   {
  95     if (null == env)
  96     {
  97       throw new NullPointerException();
  98     }
  99
 100     this.env = env;
 101   }
 102
 103
 104 }