[Swarm-Support] Customize & Protocol problem updating tipsybug from contrib

[Paul Johnson]

Hello, Swarmish folk:

My students have been pointing out to me that many of the old standards 
in Swarm's ftp do not work anymore. SO I'm updating the ones I can fix, 
and I come across some things I can fix, but don't understand very well.

Can anybody clarify for me?


Consider Barry McMullin's old standby "tipsybugs".  You can see his 
original here (which Alex Lancaster had updated):

ftp://ftp.swarm.org/pub/swarm/apps/objc/contrib/tipsybugs-2.1.tar.gz

And I put the one I "fixed" (hacked?) in here:


ftp://ftp.swarm.org/pub/swarm/apps/objc/contrib/tipsybugs-2.1-Swarm-2.1.141.tar.gz

So, what don't I understand?

1 First the problem is that the file Coord2d.m in tipsybugs is missing a 
@end at the end of the line.

gcc -c -g -O2 -march=i386 -mcpu=i686 -Wall -Wno-import -Wno-protocol 
-Werror  -D_GNU_SOURCE -DAPPNAME=tipsybugs -DAPPVERSION=2.1 
address@hidden   -I/usr/include/swarm Coord2d.m
/usr/include/swarm/defobj/Customize.h:143: warning: address@hidden' missing in 
implementation context
/usr/include/swarm/defobj/Customize.h:143: warning: incomplete 
implementation of class `Coord2d'

The compiler used to ignore that, no more, no big problem, just add it. 
 The compiler also points out that Swarm's own Customize.h is missing 
the @end. Customize.m is missing @end at the end as well.  I suspect the 
Swarm files are missing that for a reason, as is usually the case in 
Swarm. But I don't see why.


2. After adding @end at the end of Coord2d.m, then I get a problem with 
protocols:

gcc -c -g -O2 -march=i386 -mcpu=i686 -Wall -Wno-import -Wno-protocol 
-Werror  -D_GNU_SOURCE -DAPPNAME=tipsybugs -DAPPVERSION=2.1 
address@hidden   -I/usr/include/swarm ModelSwarm.m
gcc -c -g -O2 -march=i386 -mcpu=i686 -Wall -Wno-import -Wno-protocol 
-Werror  -D_GNU_SOURCE -DAPPNAME=tipsybugs -DAPPVERSION=2.1 
address@hidden   -I/usr/include/swarm Tipsybug.m
gcc -c -g -O2 -march=i386 -mcpu=i686 -Wall -Wno-import -Wno-protocol 
-Werror  -D_GNU_SOURCE -DAPPNAME=tipsybugs -DAPPVERSION=2.1 
address@hidden   -I/usr/include/swarm LatticeAgent.m
gcc -c -g -O2 -march=i386 -mcpu=i686 -Wall -Wno-import -Wno-protocol 
-Werror  -D_GNU_SOURCE -DAPPNAME=tipsybugs -DAPPVERSION=2.1 
address@hidden   -I/usr/include/swarm Agent.m
gcc -c -g -O2 -march=i386 -mcpu=i686 -Wall -Wno-import -Wno-protocol 
-Werror  -D_GNU_SOURCE -DAPPNAME=tipsybugs -DAPPVERSION=2.1 
address@hidden   -I/usr/include/swarm Lattice2d.m
gcc -c -g -O2 -march=i386 -mcpu=i686 -Wall -Wno-import -Wno-protocol 
-Werror  -D_GNU_SOURCE -DAPPNAME=tipsybugs -DAPPVERSION=2.1 
address@hidden   -I/usr/include/swarm Coord2d.m
Coord2d.m:284: warning: incomplete implementation of class `Coord2d'
Coord2d.m:284: warning: method definition for `-_I_Using' not found
Coord2d.m:284: warning: class `Coord2d' does not fully implement the 
`Copy' protocol
make: *** [Coord2d.o] Error 1


This happens because tipsybug's Coord.h file declares a protocol that
adopts the Copy protocol.

//Coord.h
#import <objectbase.h>

#import "NeighborCode.h"

@protocol Coord <Copy>

I've gone into the Swarm source, I see how examples of how macros like 
USING (and CREATING, and SETTING) are put into the h files and m files 
have parallel phase macros, PHASE(Using) and such.

If I just act like a trained monkey typing the Bible, then I am able to 
fix the problem by mimicing the Swarm source code.

In Coord.h, I put in phase using the MACROS just like the Swarm source

CREATING
USING
SETTING

And in Coord2d.m, the implementation file that adopts <Coord>, then I 
put in

PHASE(Creating)

PHASE(Setting)

PHASE(Using)

That makes the program compile and run, but I do not understand the 
reason that it works. In particular, I don't understand why it is 
looking for _I_Using at all, or why it was macro'd to be just USING, etc 
etc.

I conceptually understand the phases in Swarm, just not how this code 
implements them.


--
Paul E. Johnson                       email: address@hidden
Dept. of Political Science            http://lark.cc.ku.edu/~pauljohn
University of Kansas                  Office: (785) 864-9086
Lawrence, Kansas 66045                FAX: (785) 864-5700