CoroutineLib.java :  » Graphics-3D-2D-OpenGL » e3roid » org » luaj » vm2 » lib » Android Open Source

/*******************************************************************************
* Copyright (c) 2007 LuaJ. 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
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
******************************************************************************/
package org.luaj.vm2.lib;

import org.luaj.vm2.LuaTable;
import org.luaj.vm2.LuaThread;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Varargs;

public class CoroutineLib extends VarArgFunction {
  
  private static final int INIT    = 0;
  private static final int CREATE  = 1;
  private static final int RESUME  = 2;
  private static final int RUNNING = 3;
  private static final int STATUS  = 4;
  private static final int YIELD   = 5;
  private static final int WRAP    = 6;
  private static final int WRAPPED = 7;
  
  public CoroutineLib() {
  }

  private LuaTable init() {
    LuaTable t = new LuaTable();
    bind(t, CoroutineLib.class, new  String[] {
      "create", "resume", "running", "status", "yield", "wrap" },
      CREATE);
    env.set("coroutine", t);
    PackageLib.instance.LOADED.set("coroutine", t);
    return t;
  }
  
  public Varargs invoke(Varargs args) {
    switch ( opcode ) {
      case INIT: {
        return init();
      }
      case CREATE: {
        final LuaValue func = args.checkfunction(1);
        return new LuaThread(func, LuaThread.getGlobals() );
      }
      case RESUME: {
        final LuaThread t = args.checkthread(1);
        return t.resume( args.subargs(2) );
      }
      case RUNNING: {
        final LuaThread r = LuaThread.getRunning();
        return LuaThread.isMainThread(r)? NIL: r;
      }
      case STATUS: {
        return valueOf( args.checkthread(1).getStatus() );
      }
      case YIELD: {
        final LuaThread r = LuaThread.getRunning();
        if ( LuaThread.isMainThread( r ) )
          error("main thread can't yield");
        return r.yield( args );
      }
      case WRAP: {
        final LuaValue func = args.checkfunction(1);
        final LuaThread thread = new LuaThread(func, func.getfenv());
        CoroutineLib cl = new CoroutineLib();
        cl.setfenv(thread);
        cl.name = "wrapped";
        cl.opcode = WRAPPED;
        return cl;
      }
      case WRAPPED: {
        final LuaThread t = (LuaThread) env;
        final Varargs result = t.resume( args );
        if ( result.arg1().toboolean() ) {
          return result.subargs(2);
        } else {
          error( result.arg(2).tojstring() );
        }
      }
      default:
        return NONE;
    }
  }
}