From: Hal Fulton <hal9000@...>
Date: 2004-05-28T07:28:10+09:00
Subject: Re: true.respond_to?("clone")

Michael Campbell wrote:
> On Fri, 28 May 2004 07:15:59 +0900, Sean O'Dell <sean@celsoft.com> wrote:
>
>>Why have respond_to? at all then?  Why not just catch NotImplementedError
>>everywhere you need to check an object before trying to call a method?
> 
> Convenience?
> 
> It really can only do what it's doing though, no?  Trying to determine
> anything beyond "does there exist an implementation, however crappy or
> useless it may be" sounds a lot like trying to solve the halting
> problem.

It's not really a question of how respond_to? should behave or how much
work it should do.

The question is: Do we gain anything by defining TrueClass#clone rather
than just leaving it nonexistent?

The only rationale I can think of is that "later" there might be a
TrueClass#clone implemented, and we're leaving a placeholder for it...
but this seems unlikely to me and a flimsy justification.


Hal