From: Luke Kanies <luke@...>
Date: 2005-07-12T08:52:31+09:00
Subject: Re: class_attr_accessor

On Tue, 12 Jul 2005, Ara.T.Howard wrote:

> right you are.  it bit me a few times and was ending up writing things like
>
>    class A
>      class << self
>        attr 'a'
>        attr 'b'
>        def init
>          self.a = 42
>          self.b = 'forty-two'
>        end
>        def inherited subklass
>          subklass.init
>          super
>        end
>      end
>      self.init
>    end
>
>    class B < A
>      self.b = 42.0
>    end
>
> all over the place.

The whole '<< self' syntax still confuses me; considering how often I
could use code that's the equivalent of this, I should obviously learn
to understand it...  The newer pickaxe book implies that a new "virtual"
class is created when using this syntax; is that true when operating on
Class instances?  That is, if I do this, are there somehow two A
instances, one of them "virtual" and with the methods I've added?  I
doubt it, but the book leaves it a bit unclear.

I'll begin switching all of my 'def Class.attr...' method defs to this.
:/

> which starts being kinda ugly.  i found that i almost always wanted class
> varibles to essentially call 'super' when not over-ridden - in otherwords to
> get a reasonable value from the parent class - but this is not possible with
> either @@vars or @vars without some trickery.  so i wrote it once and called
> it traits.  ;-)

Interesting; I use class instance variables all over the place --
literally in just about every Ruby project I do -- and I almost never
have subclasses inheret values from parent classes.

Just having a builtin simple class-equivalent to the attr methods would
be very useful to me, which I think was the point of the initial post.
I love how Ruby's classes are just normal objects, but the fact that I
have to manually define all of these attr_accessors for the classes
themselves gets pretty annoying.

I'll check into 'traits', but I don't think I can use it for this
project, since I have to mostly stick to libs that are part of the
standard library.

-- 
We're not surrounded, we're in a target-rich environment!
---------------------------------------------------------------------
Luke Kanies | http://reductivelabs.com | http://config.sage.org