From: dblack@...
Date: 2007-06-09T20:10:03+09:00
Subject: Re: #respond_to? not working for dynamically generated metho

Hi --

On Thu, 31 May 2007, James Edward Gray II wrote:

> On May 30, 2007, at 3:31 PM, Robert Dober wrote:
>
>> This is very interesting, I just imagine that dynamic_finder does not
>> give consistent results depending on events outside the Ruby
>> program(*). Are you still happy with the semantics, instead of
>> respond_to? giving false negatives it gives false positives now.
>
> Well, if it can't be made accurate, that's a different thing.  First, we 
> would probably need to document that it can't be trusted in such a case.
>
>> You have created a dependency between method_missing and respond_to? I
>> really feel bad about this.
>
> I guess that means that I made it so that respond_to?() needs to be updated 
> if method_missing() is?  Yes, I guess that's right.
>
> David says that's bad.  OK.  I thought respond_to?() lying to me was bad.  So 
> I guess we just chose to care about different things.

I just raise an eyebrow at that much repeated/parallel code.

> I guess each person needs to decide what is more important to them.

I think it's just a matter of how you define respond_to? conceptually
-- as a handle on the methods in the object's method lookup path, or
as a registry of everything the object can do without raising an
error.  It's interesting in this connection that delegation adds the
delegated methods to the respond_to? roster.  I guess that summarizes
the difference for me: a method that's delegated is known to be taken
care of, whereas a method that's missing is missing (even if the
potential error can be averted).


David

-- 
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