From: dblack@...
Date: 2002-11-15T22:24:27+09:00
Subject: Re: Regexp: What does //o do?

Hi --

On Fri, 15 Nov 2002, Jim Freeze wrote:

> On Friday, 15 November 2002 at 15:23:16 +0900, nobu.nokada@softhome.net wrote:
> > Hi,
> >
> > At Fri, 15 Nov 2002 15:02:51 +0900,
> > Jim Freeze wrote:
> > > In a regex, what is the /o for (as opposed to n, i or g)?
> > >
> > > EG
> > >  re = /\A\s+/o
> >
> > This o has no meanings.  It's usefull with interpolation.
> >
> > ['\A\s+', '\S+\z'].map {|s| /#{s}/}	# => [/\A\s+/, /\S+\z/]
> > ['\A\s+', '\S+\z'].map {|s| /#{s}/o}	# => [/\A\s+/, /\A\s+/]
> >
>
> I'm confused. Why does it affect the map iterator?
>
> ['a','b'].map {|s| /#{s}/o}  # => [/a/,/a/]

I think what's happening is that the /o causes the regex to
be compiled only once, and in this case that sort of freezes
it with respect to the further iterations.


David

-- 
David Alan Black
home: dblack@candle.superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav