From: Robert Dober <robert.dober@...>
Date: 2006-07-27T04:05:19+09:00
Subject: Re: gsub

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On 7/26/06, Guillaume Carbonneau <gusxedge@gmail.com> wrote:
>
> Hi, what you really want to use if you want a clean solution is negative
> lookaheads built into your regular expression.
>
> How lookaheads work:
> http://www.regular-expressions.info/lookaround.html
>
> Search google for specific lookahead uses in Ruby as I haven't experience=
d
> them yet with this language.


Well that is nice ;)
actually that would be something like

s.sub( %r{#{Regexp.escape(r)}(?!.*#{Regexp.escape(r)})},"")

but I am afraid that this is much more expensive than the
reverse.sub.reverse trick and much less readable

Robert

On 7/26/06, Tomas Fischer <tomas_fischer99@yahoo.de> wrote:
> >
> > Hi,
> >
> > I have a string s=3D XXaaXX, in which i want to replace the last substr=
ing
> > r, which is determined at run time.
> >
> > r=3D XX
> >
> > s.gsub(/XX\z/,'') solves the problem in a static way.
> > s.gsub(r,'') solves it too, but who can I specify, that only the last
> > occurence should be replaced.
> >
> > Best regards,
> > Tomas
> >
> >
> > --
> > Posted via http://www.ruby-forum.com/.
> >
> >
>
>


--=20
Deux choses sont infinies : l'univers et la b=EAtise humaine ; en ce qui
concerne l'univers, je n'en ai pas acquis la certitude absolue.

- Albert Einstein

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