From: Robert Klemme <bob.news@...>
Date: 2003-06-28T00:27:50+09:00
Subject: Re: Using & for arrays of objects


"Simon Strandgaard" <0bz63fz3m1qt3001@sneakemail.com> schrieb im
Newsbeitrag news:pan.2003.06.27.10.33.05.161749@sneakemail.com...
> On Fri, 27 Jun 2003 13:21:42 +0200, Robert Klemme wrote:
>
> >
> > "Simon Strandgaard" <0bz63fz3m1qt3001@sneakemail.com> schrieb im
> > Newsbeitrag news:pan.2003.06.27.08.07.16.538696@sneakemail.com...
> >> On Fri, 27 Jun 2003 10:41:55 +0200, Robert Klemme wrote:
> >> > "Simon Strandgaard" <0bz63fz3m1qt3001@sneakemail.com> schrieb im
> >> >>
> >> >> There is no intersection(&) method.
> >> >
> >> > There is:
> >> > 07:31:22 [temp]: ri 'Array#&'
> >>
> >> I was refering to the code posted in the root of this thread.
> >> You can see that the adjustment I proposed uses Array#&.
> >
> > Sorry, I don't seem to understand you.  The OP used Array#& and it is
> > defined.  What did you want to say with "There is no intersection(&)
> > method"?
>
> OK.. What I meant with "no intersection method" was: That his class did
> not have a Trival#& method defined. I suggested him to use Array#& to
> do the intersection for him.
>
> Sorry, I am terrible at communition :-)

No, I'm sorry, but I think in this case you're just plain wrong. :-)  I
don't think the class needs a method & because array intersection
(Array#&) is defined as returning a single array that contains only
elements in self and the argument array.  Thus elements need only be
comparable or similar.  No Trivial#& required.  As Nobu Nakada pointed out
it was the hash method that was missing (at least in during my
experimenting).

Kind regards

    robert