At 01:31 PM 5/21/2001 +1000, Damian Conway wrote:
> > Um, this is a tiny little diversion here prompted by something that
> > came up on perl-beginners, of all places... it's not possible in
> > perl 5 to make a reference to an array or hash slice without doing
> > some copying.
> >
>
>Hey, this is *Perl*! Of course it's possible...
>
>@A = (1..10); # array
>@I = (3..5); # indices of desired slice
>
>$ref =
> sub{my%k;@k{@{+pop}}=\(@_);splice@_,$_,!$k{$_}for reverse
> 0..@_;\@_}->(@A,\@I);
Oh, well, if I'd known it was *that* succinct...
But... that *does* involve copying; the original poster was talking about
huge arrays where copying was actually significant. You've got the list of
keys and values in the temporary hash there. It certainly violates the
spirit of the request. Which still seems like a reasonable request.
A reference to a slice in perl 5 yields the list of the references to the
slice members. Is that the way it's going to be in perl 6?
