Nobuyoshi Nakada wrote:
> Hi,
>
> At Wed, 15 Nov 2006 20:50:05 +0900,
> Trans wrote in [ruby-talk:225107]:
> > My mistake. It is for Symbols that it doesn't work. I was mistakingly
> > thinking nil was the same, but that it not the case --which is great
> > b/c it makes my code obsolete! :-)
>
> I guess that Symbol in current 1.9 could have singleton
> methods.  Or, it would be possible by a hack similar to
> instance variables of them, if really desirable.
>
> > > It might be doubtful to be effective, since a Proc doesn't equal
> > > another Proc created in the same place almost.
> >
> > Hmm... yes, I mean to go one step futher and catch the module and
> > create methods within it:
>
> Point taken.

Oh, there was one more thing I got confused about last night (sorry, it
was late). Actually, the code I wrote for NilClass used delegation and
#method_missing rather than an extension. This allowed me to turn the
behavior off on the fly. And that's what I was referring to when I
spoke of safe core extensions. But we can't do that using extending
modules :-( Oh, only if we could #unextend.

T.