From: Avi Bryant <avi@...4.com>
Date: 2001-07-25T14:32:24+09:00
Subject: [ruby-talk:18508] Re: OO question

On Wed, 25 Jul 2001, Dave Thomas wrote:

> Stephen White <spwhite@chariot.net.au> writes:
> 
> > It would be nice if there was some way of showing the connection between
> > "join" and "split", "pack" and "unpack" and other related operations even
> > though they reside in different classes.
> 
> I think this is an excellent thought. Logically, if not in actual
> implementation, it would be fun to think of an orthogonal set of
> capabilities that you can add to the language. For example, you might
> logically say
> 
>     use 'byte_and_bit_access'   // ok - bad name
> 
> and String and Array would be augmented with unpack and
> pack.

Smalltalk always did this with categories - you can ask a browser,
for example, to show you all the methods in a particular category,
regardless of class.  It's also fairly common to "file-in" and "file-out"
by category.  In Ruby, of course, it's quite natural to have a file which adds
methods to several classes, so that

require 'byte_and_bit_access.rb'

would be fine right now, if the standard libraries happened to be
modularized that way.

RCR: add smalltalk-like categories to Ruby?  This would involve, at the
least, having every method know which category it belonged to, from which
you could build searches for all methods in a particular category, etc.

Avi