Hi Per, an interesting pitfall, thanks for pointing that out.
It does seem that Qlib sets the value of the repeat loop control variable to 0 at the start of the loop. Do you know how this fares on plain QDOS, not SMSQE? Regards Wolfgang > I dont know if this has been documented anywhere, but Im putting it out > here as it caused me some grief. > > It appears that Q-Liberator zeroes the loop variable on entry to a loop. > The following demo, which is acceptable (although perhaps not very > elegant) S*BASIC, will not work in the same way once compiled with Qlib. > > 100 loop = 3 > 110 cnt = 0 > 120 PRINT 'Start:'! loop, cnt > 130 REPeat loop > 140 PRINT loop, cnt > 150 cnt = cnt + 1 > 160 IF cnt >= loop: EXIT loop > 170 END REPeat loop > 180 PRINT 'End:'! loop, cnt > 190 PAUSE: QUIT > > In the Qlib-compiled version the loop is exited after a single run as > the condition cnt >= loop is met immediately, to wit 1 >= 0 > > The worrying part of this is that while I was figuring out what was > wrong, running an embedded routine like this many times, the system > crashed due to memory corruption. Whether this was due to the SBASIC or > Qlib compiled version I cant say right now. So just beware and keep on > progging! > > NB: This works, though. As long as you start out with loop = 0 > > 100 loop = 0 > 110 cnt = 3 > 120 PRINT 'Start:'! loop, cnt > 130 REPeat loop > 140 PRINT loop, cnt > 150 loop = loop + 1 > 160 IF loop >= cnt: EXIT loop > 170 END REPeat loop > 180 PRINT 'End:'! loop, cnt > 190 PAUSE: QUIT > > Per > > _______________________________________________ > QL-Users Mailing List _______________________________________________ QL-Users Mailing List
