Re: Bracket expressions with character ranges are slow

[Seth David Schoen]

Seth David Schoen writes:

> That is, using the explicit list of characters in the backet
> expression was three orders of magnitude faster!  Using the
> character class [:upper:] is also fast:
> 
> address@hidden:~$ time grep  '[:upper:]' /usr/share/dict/words > /dev/null

I was wrong about that -- my grep doesn't have the patch from

https://lists.gnu.org/archive/html/bug-grep/2010-09/msg00015.html

so it didn't warn me that I wasn't actually using the character
class I thought I was.  In fact, using the character class [[:upper:]]
is also _slow_, about as slow as using the range [A-Z].

-- 
Seth David Schoen <address@hidden> | Qué empresa fácil no pensar en
     http://www.loyalty.org/~schoen/   | un tigre, reflexioné.
     http://vitanuova.loyalty.org/     |            -- Borges, El Zahir