From: Yasushi Shoji <yashi@...>
Date: 2000-09-26T11:25:02+09:00
Subject: [ruby-talk:5120] Re: Types and ===

At Tue, 26 Sep 2000 09:55:14 +0900,
Hal E. Fulton <hal9000@hypermetrics.com> wrote:

> Still, it bothers me a little that x==y does not always
> imply x===y. But I will just have to get used to that...

how about stating:

'===' does not imply '==' at all.  '===' is defined in each class the
way to make writing case statement easier.  most classes use '==' for
'===', but some class, such as class Class and class Range uses
other.is_a?(self) and self.include?(other), respectively.

> Actually I have trouble remembering what === means --
> whether to say x === y or y === x, which are of course
> not the same.

so, i guess you don't have to remember what '===' at all ;)

I think the moment you need to remember about '===' is when you write
your own class.  you can define '===' in your own class to control
case statement.
--
         yashi