[REBOL] Re: for bug?
From: rotenca:telvia:it at: 17-Jun-2002 22:47
Hi Joel, some notes about this thread (also to clear my looping mind :-):
1) it is strange, but your simulation code is more slow on my system (W98 -
Celeron 333 view 1.2.1.3.1 and beta 1.2.5.3.1) than the standard simulated
'for
>>race 500000
0:00:03.52 0:00:04.01
2) neither your code can check this case:
for i #"^(00)" #"^(01)" 256 []
the code should do an additional test of this type (with positive bump):
if old => old + bump [break]
3) the right solution should be a consistent math overflow error with all
scalar datatype! and not a
pseudo-random [error wrap stop bug]
like it is in the actual implementation (bug is for the time! datatype!) :-)
4) I always think that
for i #"^(00)" #"^(ff)" 1 []
should stop at #"^(ff)", with or without math overflow and with or without
wrap, so 'for should check the end condition at the end of the loop and before
adding the bump value.
5) a while or until loop is the best mode to do what 'for should do, so one
can directly control what happens (and a rebol for loop is always slower than
a rebol while/until loop)
---
Ciao
Romano
