From: Jamis Buck <jamis_buck@...>
Date: 2005-02-24T01:59:29+09:00
Subject: Re: surprising: class A; end; A === A  ==> false

On 01:24 Thu 24 Feb     , Sam Roberts wrote:
> I'm used to thinking of === being MORE useful
> On thinking about it, I can see why: in A === A, A is of class Class,
> and that class is not derived from the class A, so comparison is
> false...
> 
> But this causes me some trouble, because there is no way to use
> case statements with a class:
> 
>   class A
>    Ordinal = 1
>   end
>   class B
>    Ordinal = 2
>   end
> 
>   t = A
> 
>   case t
>     when A then ...
>     when B then ...
>   end
> 
> No case will ever match!
> 
> Is my only way:
> 
>   if t == A
>     ...
>   elsif t == B
>     ...
>   elsif
>     .....
> 
> or is there some clever workaround?

You could do:

  case t.name
    when "A" then ...
    when "B" then ...
  end

or

  case t.id
    when A.id then ...
    when B.id then ...
  end

Still kind of kludgy, though.

- Jamis

-- 
Jamis Buck
jamis_buck@byu.edu
http://jamis.jamisbuck.org
------------------------------
"I am Victor of Borge. You will be assimil-nine-ed."