From: Robert Klemme <shortcutter@...>
Date: 2007-06-08T01:00:18+09:00
Subject: Re: === operator

On 07.06.2007 13:02, dblack@wobblini.net wrote:
> Hi --
> 
> On Thu, 7 Jun 2007, Bertram Scharpf wrote:
> 
>> Am Donnerstag, 07. Jun 2007, 05:32:38 +0900 schrieb Robert Dober:
>>> On 6/6/07, dblack@wobblini.net <dblack@wobblini.net> wrote:
>>> <snip>
>>>> Yes; === is called on the when expression(s), with the case object as
>>>> argument.
>>> Well you are right of course, I said now because I did not understand
>>> what OP meant :(
>>
>> Some may say it's an unexpected behaviour. Others will find
>> themselves detecting it as a welcome surprise. This is Ruby
>> at its best.
> 
> I always thought it was just the logical way to do the case statement.
> Since you're testing something about the case object, you may not know
> what it is or what its === method does:
> 
>   case x     # what is x?
>   when 1     ...
>   when "yes" ...
>   when C
>   when nil   ...
>   end
> 
> So I don't think it would make sense to have a case construct where
> === was called on x.

Another reason why that would be an odd way to do it: *all* tests then 
would have to be implemented in x's class - now how much sense would 
that make to do that?  Just think of the type test (i.e. using class 
objects in when clause)...

Kind regards

	robert