Re: Function as an argument

[Marcus G. Daniels]

>>>>> "AO" == Akiko Ogawa <- RS/GIS lab <address@hidden>> writes:

AO> 1) In my example,
AO> assuming that -scientificTest: takes one arguments and
AO> -conventionalTest: takes two arguments (though here it doesn't),
AO> is there any nice way for the -goThroughtEggWith:InObj function to
AO> detect how many arguments a passed function takes so that it can
AO> switch between [obj perform: sel with: egg] and [obj perform: sel
AO> with: egg with: somethingElse] in itself?

Well, you could look at the method name and count the ":" characters,
and do a `switch' on that number.

Another idea is to use the FArguments/FCall interface so that the
information is all packaged together.  (See below.)

AO> 2) Can a selecter be a function that returns a value, as in
AO> M(getSomething), where, -(int) getSomething?

Strictly speaking, no.  It has to be a an `id'-like thing (typically
a 32 bit value).  `int' will work most places.

#import <simtools.h> // initSwarm
#import <defobj/Create.h> // CreateDrop

@interface Target: CreateDrop
@end

@implementation Target
- (void)message: (double)arg1 arg2: (int)arg2 arg3: (const char *)arg3
{
  printf ("arg1: %f arg2: %d arg3: `%s'\n", arg1, arg2, arg3);
}
@end

int
main (int argc, const char **argv)
{
  initSwarmBatch (argc, argv);

  {
    id obj = [Target create: globalZone];
    SEL sel = M(message:arg2:arg3:);
    id <FArguments> fa = [FArguments createBegin: globalZone];

    [fa setSelector: sel];
    [fa addDouble: 2.0];
    [fa addInt: 3];
    [fa addString: "Hello World"];
    fa = [fa createEnd];
    {
      id <FCall> fc =
        [FCall create: globalZone target: obj selector: sel arguments: fa];
      
      [fc performCall];
    }
  }
  return 0;
}

/*
Local Variables:
compile-command: "$SWARMHOME/bin/libtool-swarm --mode=link gcc -DAPPNAME=fcall 
-o fcall -Wall -Werror -g -Wno-import -I$SWARMHOME/include/swarm 
-L$SWARMHOME/lib/swarm fcall.m -lswarm -lobjc"
End:
*/


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