From: Ross Bamford <rosco@...>
Date: 2006-11-13T00:40:06+09:00
Subject: Re: regular expression too big

On Sun, 12 Nov 2006 15:01:56 -0000, Peter Schrammel  
<peter.schrammel@gmx.de> wrote:

> Why is there a limitation at all? I implemented the same thing in perl
> and it no complains ...
> Is the regexp engine of perl that much better?
>

Irrespective of whether regex the best solution for your needs, it seems  
Oniguruma will improve the situation somewhat with respect to large  
regular expressions.

$ wc -w acd-holmes-return.txt
112110 acd-holmes-return.txt


$ cat bigregexp.rb
txt = File.read('acd-holmes-return.txt').split(' ')
re = /^(#{txt.map { |e| "#{Regexp.escape(e)}" }.join('|')})$/

p re =~ "beautiful"
p $&
__END__


$ ruby -v bigregexp.rb
ruby 1.8.5 (2006-08-25) [i686-linux]
bigregexp.rb:2: regular expression too big: /...[snipped].../ (RegexpError)


$ ruby9 -v bigregexp.rb
ruby 1.9.0 (2006-09-07) [i686-linux]
0
"beautiful"

-- 
Ross Bamford - rosco@roscopeco.remove.co.uk