From: Patrick Hurley <phurley@...>
Date: 2005-03-24T11:50:47+09:00
Subject: Re: (Maybe) a simple question about regex

What they said, but also if you can be more precise about your real
problem, we might be able to better model a solution. You might find
matching the expression you want and then scanning it to be more
flexible for example.


On Thu, 24 Mar 2005 11:09:51 +0900, Assaph Mehr <assaph@gmail.com> wrote:
> 
> > s = '0123456789'
> > s.scan(/\d\d/) #-> ["01", "23", "45", "67", "89"]
> >
> > Now I want to exclude "45".
> > How can I express it in the regex?
> > When it's only one character, I can use ^.
> > But for 2 characters, I don't think I can use it.
> >
> > What I want is:
> >
> > s = '0123456789'
> > s.scan(some_regex) #-> ["01", "23", "67", "89"]
> 
> Negative lookahead:
> s.scan /(?!4|5)\d\d/
> Note the OR sign ('|') between the digits, otherwise it would produce:
> ["01", "23", "56", "78"]
> 
> You need to tune it to your exact domain.
> 
> Cheers,
> Assaph
> 
>