[Python-Dev] Wild Idea for the Year
Phillip J. Eby
pje at telecommunity.com
Sun Jun 27 18:03:06 EDT 2004
At 02:38 PM 6/27/04 +0100, Armin Rigo wrote:
>On Sat, Jun 19, 2004 at 03:40:07PM -0400, Raymond Hettinger wrote:
> > s = ""
> > for e in iterable:
> > s = s + e
>Hum, it may not be impossible after all.
>http://www.python.org/sf/980695 -> an idea that seems to work and only
>involves 3 pages of obfuscated code in new well-isolated functions of
>stringobject.c is unmodified.
Looks interesting. It appears the cost is added to cases that are likely
to have longer execution times anyway. (i.e. the slow_add and slow_iadd
I notice that string_concatenate() doesn't cover the STORE_DEREF case,
however. Was that intentional?
Last question: is this actually faster when 'e' is replaced by an
expression that causes memory allocation? That is, isn't this *still*
going to be an O(n**2) operation if the string has to be relocated on each
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