From: Daniel Schierbeck <daniel.schierbeck@...>
Date: 2007-02-20T04:29:35+09:00
Subject: Re: The peak of the iceberg, was Range cannot loop down and RCR	Integer#pred

On Tue, 2007-02-20 at 04:15 +0900, Robert Dober wrote:
> On 2/19/07, Daniel Schierbeck <daniel.schierbeck@gmail.com> wrote:
> > On Mon, 2007-02-19 at 18:14 +0900, Robert Dober wrote:
> > > Hi all
> > >
> > > I was just following the thread about "loop cannot count down" and
> > > was about to propose a monkey patched method which might have been
> > > convenient for the poster.
> > >
> > > Like e.g. Range#each_down  (bad name I know).
> > >
> > > The point is, I cannot, because Range#each is based on succ, and
> > > Range#each_down would be based on pred.
> > >
> > > I just wonder if it might not be a good idea to define pred for all
> > > core classes for which succ is defined. I kind of feel stupid not
> > > having suggested that in the first place, now :(.
> > > (http://rcrchive.net/rcrs/6)
> > >
> > > Opinions?
> >
> > It seems you beat me to it :)
> Really my fault, I did not discuss it on the list, I did announce it
> though, because it seemed so simple.
> AAMOF Matz accepted it surely because of its simplicity.
> Really a mistake of mine because it could have been discussed for many
> more classes and its impact on Ranges.
> 
> Maybe you would like to lead discussion about this one, as I stole the
> other one from you ;) ?
> >
> > I'm sure it's been brought up before, and it will surely add more
> > complexity
> But I do not advocate any usage of #pred, I just advocate its presence.
> The user has the power than :)
> >to a problem that seems relatively small,
> I am not really sure it is that small, this unidirectionality seems
> somehow incorrect to me and what I said in the beginning really
> bothers me
> 
> I cannot iterate through a Range in the reverse sense.
> 
> > based on the low
> > volume of posts on it here on the mailing list.
> It is not an issue for most of us I did not run into it in two years
> of Ruby Programming but now that it was brought up for me an iceberg
> emerged. ;)

True all dat, I'm just playing the devil's advocate ;)


Cheers,
Daniel