问jheatbugs-2001-03-28中某些代码

sybbk

HeatbugModelSwarm中buildActions部分，3个try分别是做什么？查了下refbook-java-2.2，解释太简略，还是不懂，高手指点，谢谢！代码如下：
$ O2 p, H* A6 M4 A8 h' r3 h
/ }. j  r5 N* | public Object buildActions () {
    super.buildActions();
   
    // Create the list of simulation actions. We put these in
    // an action group, because we want these actions to be
    // executed in a specific order, but these steps should
    // take no (simulated) time. The M(foo) means "The message
    // called <foo>". You can send a message To a particular
    // object, or ForEach object in a collection.
        
    // Note we update the heatspace in two phases: first run
    // diffusion, then run "updateWorld" to actually enact the
" C, W0 I( j3 N0 P8 {/ ]    // changes the heatbugs have made. The ordering here is
! |4 w3 x, X% q. T0 j    // significant!
2 O* Q# s2 G) n+ s, `, }        
    // Note also, that with the additional
; P7 \/ ?& F! q# w/ \/ g* G    // `randomizeHeatbugUpdateOrder' Boolean flag we can
    // randomize the order in which the bugs actually run
    // their step rule.  This has the effect of removing any
    // systematic bias in the iteration throught the heatbug
9 K1 }: C5 E, C7 x    // list from timestep to timestep
& z" J  I0 u+ r) ^/ @- h. w, L+ ^. J8 }' r        
    // By default, all `createActionForEach' modelActions have
7 E4 H  N* o* W  ]4 }: H+ _* N    // a default order of `Sequential', which means that the
    // order of iteration through the `heatbugList' will be
9 V) W( s9 I1 k& h- Z# @8 ^    // identical (assuming the list order is not changed
3 [9 l) A/ M; H# a2 h    // indirectly by some other process).
   
    modelActions = new ActionGroupImpl (getZone ());

3 K& Q) l7 C- c" J7 C    try {
      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
      System.err.println ("Exception stepRule: " + e.getMessage ());
    }

    try {
4 h  _" F9 @. O7 C      Heatbug proto = (Heatbug) heatbugList.get (0);
      Selector sel =
        new Selector (proto.getClass (), "heatbugStep", false);
* ~+ V; c4 ^, c( b      actionForEach =
        modelActions.createFActionForEachHomogeneous$call
        (heatbugList,
         new FCallImpl (this, proto, sel,
                        new FArgumentsImpl (this, sel)));
    } catch (Exception e) {
      e.printStackTrace (System.err);
    }
   
7 l/ {5 T7 B1 }: x! `    syncUpdateOrder ();

5 H3 N8 v4 O) }/ f/ p3 v9 Z# s9 o    try {
      modelActions.createActionTo$message
, r% i1 _3 Z( G# i+ ~        (heat, new Selector (heat.getClass (), "updateLattice", false));
    } catch (Exception e) {
      System.err.println("Exception updateLattice: " + e.getMessage ());
    }
        
    // Then we create a schedule that executes the
    // modelActions. modelActions is an ActionGroup, by itself it
    // has no notion of time. In order to have it executed in
    // time, we create a Schedule that says to use the
  z7 ?4 V6 q. L3 t& ~    // modelActions ActionGroup at particular times.  This
/ x3 |2 X% D' X; K' K0 Z    // schedule has a repeat interval of 1, it will loop every
    // time step.  The action is executed at time 0 relative to
5 Z0 Y4 x  M+ t' c3 K% ]    // the beginning of the loop.

    // This is a simple schedule, with only one action that is
    // just repeated every time. See jmousetrap for more
    // complicated schedules.
6 q. p3 @- |$ B5 y- T1 I  
, G# l: {1 h  \4 r1 m/ _    modelSchedule = new ScheduleImpl (getZone (), 1);
    modelSchedule.at$createAction (0, modelActions);
# m8 m& m1 E0 T% y3 C6 \5 n3 m        
    return this;
  }