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：

public Object buildActions () {
    super.buildActions();
0 P9 s, Y3 D) n2 r+ }% A   
% n; h. M3 Z/ I$ S4 E    // 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
' {1 G; \, E0 U  I7 j4 O    // take no (simulated) time. The M(foo) means "The message
4 u0 Q* u/ V1 h) }) w+ {    // called <foo>". You can send a message To a particular
    // object, or ForEach object in a collection.
# ~$ ?& l3 c) ?2 A        
    // Note we update the heatspace in two phases: first run
! U4 P& v9 a! y) v8 G    // diffusion, then run "updateWorld" to actually enact the
0 k0 t; r2 V0 B( \; s8 J    // changes the heatbugs have made. The ordering here is
: H8 X2 C7 s) v, X$ X    // significant!
5 w8 d5 F! }* g3 Q8 ?        
0 Y- U. U) \7 ~# [    // Note also, that with the additional
- r  k- K$ q7 \2 i! d$ i/ x) N/ _    // `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
3 @/ v$ R$ A9 B    // list from timestep to timestep
. ]  s& |! `" X        
    // By default, all `createActionForEach' modelActions have
; o$ h* q3 w/ o4 [6 }& Q5 k$ |    // a default order of `Sequential', which means that the
' m2 @8 Y1 l& b8 l& M2 O    // order of iteration through the `heatbugList' will be
    // identical (assuming the list order is not changed
    // indirectly by some other process).
+ W; X# ?$ C/ N   
    modelActions = new ActionGroupImpl (getZone ());

    try {
# `0 @0 w2 i6 x. e8 Y0 [' L9 n" T      modelActions.createActionTo$message
) q8 s/ s. z! r4 @  h3 W9 a        (heat, new Selector (heat.getClass (), "stepRule", false));
    } catch (Exception e) {
      System.err.println ("Exception stepRule: " + e.getMessage ());
    }
: v& l& |' e0 I2 m+ ~! o! ?4 f
    try {
      Heatbug proto = (Heatbug) heatbugList.get (0);
6 M. d6 b4 ~. J% L; e! y" r8 [      Selector sel =
& K5 V7 F) n) h/ I* `3 ?        new Selector (proto.getClass (), "heatbugStep", false);
& @' V0 c: G# k/ _/ b7 A3 o) o5 n      actionForEach =
        modelActions.createFActionForEachHomogeneous$call
. n, ]% }. Y% `* _$ B. J        (heatbugList,
+ [5 Z5 F' g0 @" Z2 g4 ]         new FCallImpl (this, proto, sel,
' J1 S! e1 u' L                        new FArgumentsImpl (this, sel)));
7 G+ R, c: R3 q8 C; ?# \& H    } catch (Exception e) {
      e.printStackTrace (System.err);
    }
   
3 }" K0 l. i/ e    syncUpdateOrder ();

    try {
* _6 t- R7 A5 v6 r/ U2 B      modelActions.createActionTo$message
        (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
' X1 a8 n( X5 }) z7 x    // has no notion of time. In order to have it executed in
    // time, we create a Schedule that says to use the
1 ^- f5 c2 ?2 V6 Y+ b! ^! W    // modelActions ActionGroup at particular times.  This
" l& I6 d/ M2 s9 F5 l: z    // 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
/ `4 z8 `& _6 t, r+ T    // just repeated every time. See jmousetrap for more
    // complicated schedules.
2 \! V! P+ ]. e& D& L8 O3 O9 `6 \: D  
" F7 P& r8 z5 I/ |1 ^2 x3 r0 h* a    modelSchedule = new ScheduleImpl (getZone (), 1);
    modelSchedule.at$createAction (0, modelActions);
        
3 k; e+ l9 D7 r% p+ h  d+ X    return this;
  }