Adam Kennedy kirjoitti:
[»+^=«] reminds me of a P5 regex that has a comment saying "This is
black magic. Don't touch!". --That's-- my complaint.
I look at...
>>but the basic operator there is just ^, with a + modifier to indicate
>>numeric XOR, = to indicate an assignment operator, »« to indicate
>>explicit parallelism, and now [] to indicate reduction
...and I just mind-wipe... so it's doing WHAT exactly? I've read it 5
times and I still have no idea. And reduction? I write 25,000+ lines of
Perl a year, and if you are talking about something like
List::Util::reduce, I think I've used it maybe twice?
Just trying to guess:
(Here @a, @b, @c all have same length for simplicity)
[>>+^=<<] (@a, @b, @c)
# reduction: place the op between each item in the given list
@a >>+^=<< @b >>+^=<< @c
# hyper-op: apply op in parallel for items in lists
for @a Y @b Y @c -> $a is rw, $b is rw, $c {
$a +^= $b +^= $c
}
# and finally (+^= is right-associative)
for @a Y @b Y @c -> $a is rw, $b is rw, $c {
$b = $b +^ $c;
$a = $a +^ $b;
}
I'm not too familiar with xor, so here's an easier example with plain +=
my @a = (1,2,3);
my @b = (10,20,30);
my @c = (100,200,300);
[>>+=<<] (@a, @b, @c);
# i.e. @a >>+=<< @b >>+=<< @c
# now @c = (100, 200, 300)
# @b = (110, 220, 330)
# @a = (111, 222, 333)
--
Markus Laire
<Jam. 1:5-6>
