From: "Wolfgang Nádasi-Donner" <wonado@...>
Date: 2007-02-15T03:10:05+09:00
Subject: Re: Programmatically turning a Regexp into an anchored Regexp

Greg Hurrell schrieb:
> Is there any programmatic way to take a Regexp like /foo/ and turn it
> into an anchored Regexp (/^foo/)? I'm looking for a programmatic way
> to do this because the actual Regexp is dynamic, not known until run
> time.
> 
> I'm wishing for an option or method similar to the EXTENDED,
> IGNORECASE, MULTILINE options, except for anchoring.
> 
> I suspect the answer will be "no", but I wanted to ask anyway before
> giving up hope...
> 
> Cheers,
> Greg
> 

irb(main):001:0> r1 = /foo/
=> /foo/
irb(main):002:0> "the foo in the middle".gsub(r1, '###')
=> "the ### in the middle"
irb(main):003:0> "foo at the beginning".gsub(r1, '###')
=> "### at the beginning"
irb(main):004:0> "foo at the beginning".gsub(/^#{r1}/, '###')
=> "### at the beginning"
irb(main):005:0> "the foo in the middle".gsub(/^#{r1}/, '###')
=> "the foo in the middle"

O.K.?

Wolfgang N�dasi-Donner