Hi,
I spent all weekend buring imperative brain cells, and finally came up
with some code that worked, but encountered something I don't
understand. The code ...
fun {DoScan Is}
% Return a list that is the list of sub-strings of it's input
% defined by the delimiter character (space)
X
in
% Descend into the source string and work on the way out
case Is
of nil then
nil | nil
[] I|Ir then
X = {DoScan Ir}
case I
of & then
nil | X
else
(I|X.1) | X.2
end
end
end
works beautifully, and I must say it surprised me how elegantly it came
out after all the struggle (and particularly klunky code) I went through
to get my head around it.
Anyway, the first version had the the list construction things as
[ nil nil ]
[ nil X ]
[ I|X.1 X.2 ]
but as it was coming back out of the recursion, the second element of
the list from [I|X.1 X.2] was getting increasingly nested. eg after a
couple of returns up the stack, the function was returning
[[105 110] [[nil]]]
instead of what I expected which would be
[[105 110] nil ]
Can someone explain that? What is the difference between
[ nil nil ]
and
nil | nil
Cheers,
Jonathan.
PS ... I'm really starting to love Oz/Mozart, despite that it makes my
head hurt. :)
_________________________________________________________________________________
mozart-users mailing list
[email protected]
http://www.mozart-oz.org/mailman/listinfo/mozart-users
