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：

9 X% F: z+ C  b public Object buildActions () {
    super.buildActions();
9 A6 z) h# K( s0 ?0 h   
) C' f& @# q5 h% ^    // Create the list of simulation actions. We put these in
* y6 x7 d& C$ {, Z# N9 P' n2 s    // 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
& Q: \/ n" _; [& p0 Q+ `/ h. U3 S    // 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
# C& P9 e# ^! c( Z. M+ m4 z    // diffusion, then run "updateWorld" to actually enact the
5 ]+ ]2 L0 Q1 H+ q: f& E8 }# n    // changes the heatbugs have made. The ordering here is
    // significant!
        
    // Note also, that with the additional
    // `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
    // list from timestep to timestep
        
3 x- W4 C6 N5 S1 }: ?' i    // By default, all `createActionForEach' modelActions have
: v9 r% O5 _% L    // a default order of `Sequential', which means that the
3 h2 j$ |6 D# z+ W; r% I- X    // order of iteration through the `heatbugList' will be
    // identical (assuming the list order is not changed
    // indirectly by some other process).
) K5 Z( E2 d" z   
    modelActions = new ActionGroupImpl (getZone ());
8 w; K# @2 |+ M7 T. }4 V
% U% p* l" j- p. V7 W$ v' C1 V8 E    try {
; |3 E$ Z; _" |# c  T      modelActions.createActionTo$message
9 ?# V& x+ V7 v  `; X6 _; `: X        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
( i! W5 z5 W! Q' D$ O      System.err.println ("Exception stepRule: " + e.getMessage ());
    }

' I) W. G! e8 R# \, l    try {
      Heatbug proto = (Heatbug) heatbugList.get (0);
      Selector sel =
0 |$ H5 }' f8 G' r& p. I        new Selector (proto.getClass (), "heatbugStep", false);
5 ^- c; m& `6 L1 \* g- w      actionForEach =
        modelActions.createFActionForEachHomogeneous$call
        (heatbugList,
         new FCallImpl (this, proto, sel,
  ?$ @, P' S* d8 r" t                        new FArgumentsImpl (this, sel)));
    } catch (Exception e) {
      e.printStackTrace (System.err);
    }
   
    syncUpdateOrder ();

    try {
      modelActions.createActionTo$message
9 n2 ~  E# @. R8 p8 @        (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
& T7 l" k3 r; l2 H5 K5 _% s    // 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
) P* G" _6 L" q$ o8 _$ W0 c    // modelActions ActionGroup at particular times.  This
    // schedule has a repeat interval of 1, it will loop every
    // time step.  The action is executed at time 0 relative to
    // the beginning of the loop.

    // This is a simple schedule, with only one action that is
) v  l/ U: T7 s1 i    // just repeated every time. See jmousetrap for more
9 L6 C& K0 x1 K" D/ S    // complicated schedules.
  
8 k( N' C4 C5 ]& F7 s1 H; Y, y    modelSchedule = new ScheduleImpl (getZone (), 1);
    modelSchedule.at$createAction (0, modelActions);
        
: X( w* k, {" H! N5 D* U. E  _    return this;
# Q% \9 n: q6 @; ^, x0 F  }