From: Robert Klemme <bob.news@...>
Date: 2005-04-28T21:34:33+09:00
Subject: Re: Scanning a String


"David A. Black" <dblack@wobblini.net> schrieb im Newsbeitrag
news:Pine.LNX.4.61.0504280509220.30582@wobblini...
> Hi --
>
> On Thu, 28 Apr 2005, Robert Klemme wrote:
>
> >
> > "David A. Black" <dblack@wobblini.net> schrieb im Newsbeitrag
> > news:Pine.LNX.4.61.0504280320190.13336@wobblini...
> >> Hi --
> >>
> >> On Thu, 28 Apr 2005, Robert Klemme wrote:
> >>> Yes, it's preferred because it's faster.  Although your variant
works,
> > I
> >>> usually prefer to put the correct number of backslashes in there:
> >>>
> >>> "pious".gsub(/([aeiou])(?=[aeiou])/, '\\1\'\\2')
> >>
> >> Why do you consider that more correct?
> >
> > Although both produce the same:
> >
> >>> p '\1'
> > "\\1"
> > => nil
> >>> p '\\1'
> > "\\1"
> > => nil
> >
> > because Ruby is so kind to take "\1" literally (i.e not using the
> > backslash as escaping char because "\1" is not an escaping sequence).
I
> > prefer to explicitely escape the backslash and put the "1" in there
> > literally.  IMHO it's more fail safe when changes are done (especially
> > when changing single quotes to double quotes, see below).
>
> If you're talking about double quotes then clearly it has to be "\\1".
> I meant specifically in the case of single quotes.

Well, yes.  But quotes don't necessarily stay single through the course of
a software's lifecycle - with all this dating and matching around... :-)
Sorry, drifting off-topic.

>  Anyway, it's not a
> big deal -- I was just curious.

Thought so.  I hope I could satisfy your curiosity. :-)

Kind regards

    robert