On Sun, 27 Feb 2005 02:20:59 -0700, [EMAIL PROTECTED] (Luke Palmer) wrote:
> Luke Palmer writes:
> > Autrijus Tang writes:
> > > Just a quick question: Is Hash keys still Strings, or can they be
> > > arbitary values?
> >
> > They can be declared to be arbitrary:
> >
> > my %hash is shape(Any);
> >
> >
> > > If the latter, can Int 2, Num 2.0 and Str "2" point to different
> > > values?
> >
> > That's an interesting question. Some people would want them to, and
> > some people would definitely not want them to. I think the general
> > consensus is that people would not want them to be different, since in
> > the rest of perl, 2 and "2" are the same.
>
> I forgot an important concretity. Hashes should compare based on the
> generic "equal" operator, which knows how to compare apples and apples,
> and oranges and oranges, and occasionally a red orange to an apple.
>
> That is:
>
> 3 equal 3 ==> true
> 3 equal { codeblock } ==> false
> 3 equal "3" ==> true
>
I would have assumed a hash who shape was defined as C<Int> to perform the
hashing function directly on the (nominally 32-bit) binary representation Int
2.
Likewise, c<my % hash is shape(Double)>, would perform the hashing on the
binary
rep of the (nom.64-bit) Double value.
And C<my %hash is shape(Ref)>, on the address of the key passed?
By extension, a C<%hash is shape( Any )> would hash the binary representation
of
whatever (type of) key it was given, which would make keys of 2, 2.0, '2',
'2.0', (Int2)2 etc. all map to different keys.
If C<%hash is shape(Any)> maps all the above representation of 2 to the same
value, then C<my %hash is shape(Any)> becomes a synonym for
C<%hash is shape(Scalar)>.
(is that the same as C<my %hash of Scalar>?).
If my auumption is correct, then that would imply that each type hash or
inherits a .binary or .raw method to allow access to the internal
representation?
> Luke
