Re: Possible to "promote" an object from one class to another?

[Marcus G. Daniels]

>>>>> "PJ" == Paul Johnson <address@hidden> writes:

PJ> Is there an automagical way to say "aPrivate you are now of class
PJ> Sargent. Keep your IVars and take on the properties of this class
PJ> Sargent"?

Yes, this is possible by assigning to the class ivar in an instance¹.
There's a macro in Swarm called setClass to do this.

¹: This is strictly an Objective C (or Lisp) thing. 
   Languages like Java will require instantiation of a new object.

Here's an example:

#import <simtools.h> // initSwarmBatch
#import <objectbase/SwarmObject.h>

@interface Private: SwarmObject
- shoot;
- run;
- duck;
@end

@interface Sargent: Private
- order;
@end

@implementation Private
- shoot
{
  printf ("[%s] Shoot!\n", [self getName]);
  return self;
}

- run
{
  printf ("[%s] Run\n", [self getName]);
  return self;
}

- duck
{
  printf ("[%s] Duck\n", [self getName]);
  return self;
}
@end

@implementation Sargent
- order
{
  printf ("[%s] Do it!\n", [self getName]);
  return self;
}
@end

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

  initSwarmBatch (argc, argv);

  soldier = [Private create: globalZone];

  [soldier run];
  
  setClass (soldier, [Sargent self]);
  [soldier run];
  [soldier order];

  exit (0);
}

/*
Local Variables:
compile-command: "/opt/src/mgd/packages/development/egcs/bin/gcc -o hindu -g 
-Wno-import -L/opt/SUNWtcl/8.0/sun4/lib -R/opt/SUNWtcl/8.0/sun4/lib 
-L/opt/SDGblt/2.4g/lib -R/opt/SDGblt/2.4g/lib -L/opt/SDGlibffi/1.20/lib 
-R/opt/SDGlibffi/1.20/lib -L/opt/src/mgd/packages/swarm/swarm/lib 
-R/opt/src/mgd/packages/swarm/swarm/lib 
-L/opt/src/mgd/packages/development/zlib/lib 
-R/opt/src/mgd/packages/development/zlib/lib -L/usr/local/X11/lib 
-R/usr/local/X11/lib -L/usr/openwin/lib -R/usr/openwin/lib 
-L/opt/SDGhdf5/1.0.1/lib -I/opt/src/mgd/packages/swarm/swarm/include hindu.m 
-ljavaswarm -ljavaswarmstubs -lanalysis -lspace -lsimtools -lsimtoolsgui 
-lactivity -ltkobjc -lrandom -lobjectbase  -ldefobj -lcollections -lmisc  
-ltclobjc -ltk8.0 -ltcl8.0 -lBLT -lsocket -ldl -lnsl -L/usr/openwin/lib -lhdf5 
-lpng -lz -lXpm -lX11 -lffi -lm -lobjc -lpthread -lposix4"
End:
*/

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