From: ara.t.howard@...
Date: 2007-02-18T05:27:54+09:00
Subject: Re: Oppinions on RCR for dup on immutable classes

On Sun, 18 Feb 2007 Ara.T.Howard@noaa.gov wrote:

> On Sun, 18 Feb 2007, Dean Wampler wrote:
>
>> 
>> As someone else commented, perhaps the real issue is that
>> 5.respond_to?(:dup) returns true yet 5.dup raises, so you have no way of
>> knowing in advance that you shouldn't call dup.
>> 
>
> i simply do not understand this line of thinking - every call to every object
> always has that characteristic
>
>  f.respond_to? :read  #=> true
>  f.gets               # EOFError
>
>  q.respond_to? :pop   #=> true
>  q.pop(true)          #=> ThreadError if empty
>
> to me this really seems like a dynamic vs static issue - i just don't see how
> ruby can save you, regardless of the impl of dup, or any other method.  one
> cannot avoid hanlding runtime exceptions in a dynamic language.  one cannot
> know in advance whether it's ok to call something - even if the object
> responds to it.

   ... or even if it doesn't:  method_missing

-a
-- 
we can deny everything, except that we have the possibility of being better.
simply reflect on that.
- the dalai lama