Wondering about compile time error checking

[Paul Johnson]

I'm running the swarm snapshot June 6, 2000. 

I wrote a dynamic scheduling setup and mistakenly got a selector wrong. 
A statement:

  [schedule at: x createActionTo: self message: M(moveTo:): position ]; 

Referred to a nonexistent method, moveTo:, so the program crashed with
no message like "object does not respond to "moveTo:".  Could there be
or has there ever been compile-time checking to see if objects implement
the method in the createActionTo: statement? I keep thinking there used
to be a warning about this kind of mistake.


Here is the backtrace from the debugger-it does point to the right line,
I just didn't understand the problem for a while:

#0  0x401c1b2b in ?? ()
#1  0x4016b896 in ?? ()
#2  0x4016b736 in ?? ()
#3  0x40171cc8 in ?? ()
#4  0x8054b86 in _i_Citizen__scheduleAvailableWorld_Start_Duration_
(self=0x818ea88,
    _cmd=0x8062ad8, position=0x818f058, x=1, d=4) at Citizen.m:1258
#5  0x8052909 in _i_Citizen__step (self=0x818ea88, _cmd=0x805cbf8) at
Citizen.m:459
#6  0x4001396b in ?? ()
#7  0x401cf613 in ?? ()
#8  0x401c1007 in ?? ()
#9  0x4016ba23 in ?? ()
#10 0x40175caf in ?? ()
#11 0x40175b89 in ?? ()
#12 0x40175b89 in ?? ()
#13 0x40175b89 in ?? ()
#14 0x40175b89 in ?? ()
#15 0x40175b89 in ?? ()
#16 0x401758e9 in ?? ()
#17 0x40176014 in ?? ()
#18 0x40173735 in ?? ()
#19 0x4004cc5c in ?? ()
#20 0x4004d7df in ?? ()
#21 0x80497f8 in main (argc=1, argv=0xbffffaa4) at main.m:49
#22 0x405bb1eb in ?? ()

I don't know why ?? appears in so many of these lines. Until I came
across this problem, I was getting file/line numbers from swarm itself
for other crashes.

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

                  ==================================
   Swarm-Support is for discussion of the technical details of the day
   to day usage of Swarm.  For list administration needs (esp.
   [un]subscribing), please send a message to <address@hidden>
   with "help" in the body of the message.