David Green wrote:
> Jon Lang wrote:
>> Would it be reasonable to allow hashes to use .[] syntax as something
>> of a shortcut for ".iterator in list context", thus allowing
>> autosorted hashes to partake of the same sort of dual cardinal/ordinal
>> lookup capabilities that lists with user-defined array indices have?
>
> I thought it already did, but apparently it's something that we discussed
> that didn't actually make it into S09. I agree that .[] should apply to
> hashes just as .{} can apply to arrays. The hashes don't even need to be
> sorted -- %h[$n] would basically be a shorter way of saying
> @(%h.values)[$n], in whatever order .values would give you.
I believe that the order that .values (or is that :v?) would give you
is determined by .iterator - which, if I'm understanding things
correctly, means that any use of :v, or :k, :p, or :kv, for that
matter, would autosort the hash (specifically, its keys).
Or am I reading too much into autosorting?
Bear in mind that keys are not necessarily sortable, let alone
autosorted. For instance, consider a hash that stores values keyed by
complex numbers: since there's no way to determine .before or .after
when comparing two complex numbers, there's no way to sort them -
which necessarily means that the order of :v is arbitrary, making
%h[0] arbitrary as well. This is why I was suggesting that it be
limited to autosorted hashes: it's analogous to how @a{'x'} is only
accessible if you've actually defined "keys" (technically,
user-defined indices) for @a.
--
Jonathan "Dataweaver" Lang
