From: Rick DeNatale <rick.denatale@...>
Date: 2007-10-25T03:53:02+09:00
Subject: Re: string method that takes in a regex

On 10/24/07, Gregory Seidman <gsslist+ruby@anthropohedron.net> wrote:
> On Thu, Oct 25, 2007 at 03:06:36AM +0900, Parv G. wrote:
> > Hi,
> > Is there a string method that takes in a regular expression AND returns
> > a boolean value?
> >
> > Looking at the documentation i can't find a method that meets my
> > requirements (very surprising).
>
> % irb
> >> /foo/ === 'foo'
> => true

although

      'foo' === /foo/
     => false

=== is non-symmetric.

That said, I think that there are very few cases in Ruby where you
actually need an instance of either TrueClass or FalseClass, those
being when you want to use the non-shortcut methods

    |  instead of ||
and
   & instead of &&

or the exclusive or operator ^

In these few cases you might have to do (expr == true) & expr2
instead of just expr & expr2

There's also !!expr but be careful with that
http://www.therailsway.com/2007/8/1/dangers-of-cargo-culting

-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/