From: daz <dooby@...10.karoo.co.uk>
Date: 2005-08-01T14:46:04+09:00
Subject: Re: Defining regexp's and variables set by them


Garance A Drosehn wrote:
> The thing is, by changing 'check' to '(check|test)', I have to
> remember that the when clause also needs to change from
> referencing $1 to referencing $2.  Note that in this case I do
> not *care* whether it matched 'check' as opposed to 'test'.
> Either word is acceptable to me, so I do not need the actual
> value of $1 for anything.

Hi Garance,

You can prevent the grouped expression from creating a
back-reference by using the ?: extension ...


s = 'start: check 41 is less than ...'

re_simple = /check (\d+)/
s =~ re_simple
p [$1, $2]  #->  ["41", nil]

re_simple = /(?:check|test) (\d+)/
s =~ re_simple
p [$1, $2]  #->  ["41", nil]


HTH,

daz