On 4/10/13 12:15 AM, Dan Douglas wrote:
> On Tuesday, April 09, 2013 10:23:34 PM Chet Ramey wrote:
>> On 4/9/13 9:56 PM, Dan Douglas wrote:
>>> Erm, here it is in a less unreadable format:
>>
>> It is pretty slow. You forgot to enable `extglob'.
>
> D'oh!
>
> Bad algorithm? I suppose it's lots of backtracking and maybe has to test
> every
> substring for every position in the string. In my version it took about .3 of
> a sec, but combining all that into one string with x=${a[*]}, doing the same
> on x took about 10 seconds. It's still 0.00 in ksh/zsh.
Yep. It's not a regexp engine, it's an interpreted-on-the-fly matcher.
There aren't as many opportunities for optimization, though I imagine
there are some. ksh and zsh translate those patterns into regexps,
compile them, and execute them across the strings.
Chet
>
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU [email protected] http://cnswww.cns.cwru.edu/~chet/
