Berger, Daniel
3/31/2006 3:31:00 PM
> -----Original Message-----
> From: ara.t.howard@noaa.gov [mailto:ara.t.howard@noaa.gov]
> Sent: Friday, March 31, 2006 8:21 AM
> To: ruby-talk ML
> Subject: Re: TrueClass/FalseClass vs. Boolean
>
>
> On Fri, 31 Mar 2006, Christian Neukirchen wrote:
>
> > "baumanj@gmail.com" <baumanj@gmail.com> writes:
> >
> >> Since everything in ruby is an object, there need to be
> objects for
> >> representing true and false. Once you have those, why do
> you need a
> >> Boolean class?
> >
> > if a.kind_of? Boolean
> >
> > case y
> > when Integer
> > when Boolean
> > end
> >
> > I often wanted this shortcut...
>
> indeed. i tend to use
>
> case obj
> when Klass
> when TrueClass, FalseClass
> end
>
> which is ugly.
>
> another thing a real Boolean class could give is a 'maybe'
> obj such that
>
> maybe or true -> maybe
> maybe or true and false or true -> maybe
> maybe and false -> maybe
>
> although i can't think of anything attm to do with this it
> would undoubtably lead to some nice logical constructs that
> more closely parallel the way we think.
Think 'NULL' in databases, where 'NULL' is may not mean true or false,
but unknown. At the moment, NULL maps to nil, which is false.
> i've brought this up once or twice before - maybe we should
> just put together a patch and send to ruby-core?
It's been proposed and rejected by Matz once already.
Regards,
Dan