Dan Sugalski wrote:
I dunno. One of the things I've seen with coroutines is that as long as
you call them with no arguments, you get another iteration of the
coroutine--you actually had to call it with new arguments to reset the
thing.
The formulation of coroutines I favour doesn't work like that.
Every time you call a suspended coroutine it resumes from immediately
after the previous C<yield> than suspended it. *And* that C<yield>
returns the new argument list with which it was resumed.
So you can write things like:
sub pick_no_repeats (*@from_list) {
my $seen;
while (pop @from_list) {
next when $seen;
@from_list := yield $_;
$seen |= $_;
}
}
# and later:
while pick_no_repeats( @values ) {
push @values, some_calc($_);
}
Allowing the list of choices to change, but repetitions still to be avoided.
OTOH, forcing a closure allows you to have multiple versions of the same
coroutine instantiated simultaneously, which strikes me as a terribly
useful thing.
Yep!
Perhaps we'd be better with an explicit coroutine instantiation call, like:
$foo = &bar.instantiate(1, 2, 3);
or something.
Ew!
(Or not, as it is ugly)
That'd be my vote! ;-)
Damian
