Luke Palmer writes:
>
> for parallel(<>, 0..Inf) -> $line, $count {
> FIRST { $line //= "#!/usr/bin/perl" }
> # processing...
> NEXT { print STDERR "Next line...\n" }
> LAST { print STDERR "Done\n" }
> }
>
....
>
> Also, keep in mind that that C<parallel> function can be any (possibly
> user-defined) function. I really like that interface. Also keep in
> mind that that may not be The Interface :( i.e. still under debate ).
>
is parallel ( or whatever I pu there ) *always* a lazy function or it
returns a lazy list . I dont exactly see the differnce in case of
parallel(<>, 0..Inf) .
but in more "earthly" example
@a = (1,2,3); @b = qw( a b c ) ;
for parallel(@a,@b) { $^x mumble $^y }
will parallel *first* evaluate to ( 1 , "a" , 2, "b" , ... "c" )
and then for "walk" it over -- or parallel lazyli "yeld" one value at
a time when for request .
what I am concerned with here is : will for - parallel pair be smart
enough to optimize away unnecessary ( and CPU - costly ) reshuffling
of @a,@b -> (@a[0], @b[0], @a[1], @b[1], ... ) . or , actually I am
talking about imaginary problem and this reshuffling happens in zero
time. ( But *I* always can write parallel-like function that will do
it *very* inefficiently . so what happens in this case )
since I feel that I am not *very* clear , just one question :
what is faster ( in perl6 ) ?
for parallel(@a,@b) { mumble $^x, $^y } # assuming parallel stop when
# one of the arrays is exhosted
or
my $i=0;
my $x,$y;
loop {
$x = @a[$i ] or last loop
$y = @a[$i++] or last loop
mumble $x , $y ;
}
arcadi
