On Fri, 13 Aug 2004 11:36:05 -0700, Larry Wall <[EMAIL PROTECTED]> wrote:
> Yes, that's precisely why I'm trying to generalize Ruby's single
> "magic" block into one or more ordinary parameters.
Excellent. :)
> Two anonymous adverbs? Hmm. While I can think of ways to force it to
> work, I'm inclined to disallow it simply because it'd make another
> arbitrary rule we'd have to explain.
And there's quite a bit to explain already.
> You know, at some point you just break down and write them positionally:
>
> @array.each( { $^odd.bar() }, { $^even.baz() });
Speaking of which, let's talk a little bit about how I'd write these
methods. After looking at Apocalypse, Exegesis, and Synopsis 6 again,
I have a few more questions. There are two different ways used to
declare a subroutine or method:
sub foo (&block) {
&block('foo');
}
and
sub foo (Code $block) {
$block('foo');
}
Which is right? both? The second seems more extensible. And that leads
me to another question: can a slurpy array pick up a block?
sub foo ([EMAIL PROTECTED]) {
say ref @args[0]; # @args[0].type?
}
foo { $^a =~ /bar/ }; # does this print "Block\n"?
It'd be nice to be able to declare my each method like so:
class Array {
method each($self: [EMAIL PROTECTED]) {
my $i = 0;
my @results;
for @$self -> $elem {
my $block = @blocks[ $i++ % [EMAIL PROTECTED] ];
@results.push( $block($elem) );
}
return @results;
}
}
But that still doesn't let me call that like I'd want;
my @r = @array.each :{ $^first * 2 }
:{ $^second * 9 }
:{ $^third * 42 };
The other thing I'm wondering is how to apply adverbs to the results
of a function, if that's even possible. I believe this is valid:
my $odd = 1... :by(2) # an infinite list of odd numbers
But this?
sub odd_numbers([EMAIL PROTECTED] of Pair) {
return 1...;
}
my $odd = odd_numbers :by(2);
Does that pass C<by => 2> as a Pair to the function? Or does it apply
the adverb to the result? Maybe I need to do this?
my $odd = (odd_numbers) :by(2);
My head is swimming at this point, so I'd better give it a rest.
matt
> On the other hand, the parser will have to deal with multi-block
> structures all the time, so perhaps something could be modelled on
> how we eventually handle if/elsif/else, presuming we actually
> declare those as macros, and not strictly as grammar rules.
>
> Larry
