Re: Coroutine Question

[Damian Conway]

John Macdonald wrote a lovely summary of coroutines [omitted]. Then added:
> I'd use "resume" instead of "coreturn"
We've generally said we'd be using "yield".
> and the interface for resume would allow values to be sent
> in as well as out.
Indeed. As John suggested, the "yield" keyword (or whatever we call it) will 
evaluate to the argument list that is passed when the coroutine is resumed.

> sub byn(@base) is coroutine($count,@add) {
>     while(1) {
>         push(@base,@add);
>         return undef unless @base;
>         ($count, @add) = resume .call (splice @base, 0, $count );
>     }
> }
Under the "stupid" proposal, that would be:
  sub byn(@base) {
      return coro ($count, [EMAIL PROTECTED] is copy) {  # Anonymous coroutine
          while (1) {
              push @base, @add;
              return undef unless @base;
              ($count, @add) = yield splice @base, 0, $count;
          }
      }
  }
> my $co = byn(1..10);
>
> print $co.resume(3);          # 1 2 3
> print $co.resume(2,50..56)    # 4 5
> print $co.resume(10);         # 6 7 8 9 10 50 51 52 53 54
> print $co.resume(10);         # 55 56
> print $co.resume(10);         # (undef)
> print $co.resume(10);         # exception or undef
Which would become:
  my $co = byn(1..10);
  print $co(3);                 # 1 2 3
  print $co(2,50..56)           # 4 5
  print $co(10);                # 6 7 8 9 10 50 51 52 53 54
  print $co(10);                # 55 56
  print $co(10);                # undef
  print $co(10);                # exception
Damian