Re: RFC 90 (v1) Builtins: zip() and unzip()

[Tom Hughes]

In message <[EMAIL PROTECTED]>
          Graham Barr <[EMAIL PROTECTED]> wrote:

> On Fri, Aug 11, 2000 at 03:30:28PM -0000, Perl6 RFC Librarian wrote:
>
> > In order to reverse this operation we need an C<unzip> function:
> >
> >   @zipped_list = zip(\@a,\@b);   # (1,2,3,4,5,6)
> >   @unzipped_list = unzip(3, \@zipped_list);   # ([1,3,5], [2,4,6])
>
> Is unzip used that often ?

I wondered the same thing. As far as I can tell from a quick perusal
of my copy of "Introduction to Functional Programming" there isn't a
direct inverse of zip in Miranda.

Of course if the array slicing RFC goes through you could always
extract the original lists from a zipped list using array slices.

> > =head1 IMPLEMENTATION
> >
> > The C<zip> and C<unzip> functions should be evaluated lazily.
>
> lazily ? why, no other operator does by default (I am asuming here)

Currently... I thought one idea for perl6 was to make more things
use iterators instead of creating large temporary lists.

Tom

-- 
Tom Hughes ([EMAIL PROTECTED])
http://www.compton.nu/
...I'm so close to hell I can almost see Vegas!