> -----Original Message-----
> From: Damian Conway [mailto:[EMAIL PROTECTED]
> Sent: Saturday, October 01, 2005 8:53 AM
> To: perl6-language@perl.org
> Subject: Re: Look-ahead arguments in for loops
>
> Austin Hastings wrote:
>
> > All of these have the same solution:
> >
> > @list = ...
> > for [undef, @list[0...]] ¥ @list ¥ [EMAIL PROTECTED], undef] -> $last,
> > $curr,
> > $next {
> > ...
> > }
> >
> > Which is all but illegible.
>
> Oh, no! You mean I might have to write a...subroutine!??
>
> sub contextual (@list) {
> return [undef, @list[0...]] ¥ @list ¥ [EMAIL PROTECTED], undef]
> }
>
> for contextual( create_list_here() ) -> $last, $curr, $next {
> ...
This looks useful enough to be in the core, but it needs a couple of
parameters, one to say how many copies of the list it zips up, and another
to say what the first offset is.
sub contextual($number_of_copies, $first_offset, @list) {...} # I'm not
sure how to write it.
Then your example would be
for contextual(3, -1, create_list_here() )-> $last, $first, $next {
Joe Gottman
