On Sun, 03 Jul 2005 01:01:18 -0400, Christopher Subich <[EMAIL PROTECTED]>
wrote:
>Steven D'Aprano wrote:
>> comps. But reduce can't be written as a list comp, only as a relatively
>> complex for loop at a HUGE loss of readability -- and I've never used
>> Lisp or Scheme in my life. I'm surely not the only one.
>
>See my reply to your other post for a more detailed explanation, but I
>don't think that the for-loop solution is much less readable at all, and
>the additional complexity involved is simply setting the initial value
>and result for the accumulator. The for-loop solution is even more
>flexible, because it can include anonymous code blocks and not just
>expressions.
>
>One caevat that I just noticed, though -- with the for-solution, you do
>need to be careful about whether you're using a generator or list if you
>do not set an explicit initial value (and instead use the first value of
>'sequence' as the start). The difference is:
>_accum = g.next()
>for i in g: _accum = stuff(_accum,i)
>
>versus
>_accum = g[0]
>for i in g[1:]: _accum = stuff(_accum,i)
In either case, you want to write:
i = iter(g)
_accum = i.next()
for elem in i:
_accum = stuff(_accum, elem)
You also want to catch the StopIteration from that explicit .next() call, but
that's an unrelated matter.
Jp
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