Your first variation seem to destroy the array that is
handed to it. Dump the original array before and after
your reverse and see. Fast, but kinda rude. =)
Your second variation seems to do it in line, reversing
the original array! I hadn't thought about making
one that does it all in place! =)
Your third variant was the one that left the original
undisturbed.
I really like the map variation, and I like better
never making a named variable:
use Data::Dumper;
my @names = (1, 2, 3, [4, 5, 6, [7, 8, 9], 10], 11, 12, [13, 14] );
print Dumper(@names);
my $reved = rev_arr5(\@names);
print Dumper(@names);
print Dumper(@$reved);
# less than 80 col! yay!
sub rev_arr5 {
return [map { ref eq 'ARRAY' ? rev_arr5($_) : $_ } reverse @{shi
+ft()}];
}
sub rev_arr2a {
@{$_[0]} = map { ref eq 'ARRAY' ? rev_arr2a($_) : $_ } reverse @
+{$_[0]};
}
sub rev_arr4 {
my $arr = [reverse @{shift()}];
foreach (@$arr) {
if ( ref $_ eq 'ARRAY' ) {
$_ = rev_arr4 ($_);
}
}
return $arr;
}
That version is safe from unintended effects (plays
well with others) and is lickety-split. BTW I ran 1 million
reps of eash thru Benchmark::cmpthese so really this is
a waste to optimize anyway. =) I also tested a variant of
Ted's number 2 that has no return at the end, since it
modifies in place anyway.
Rate Extremely_orig Extremely_4 Ted_var_3 Extremely_5 Ted_var_2 Ted_var_2a
Extremely_orig 106045/s -- -3% -28% -46% -47% -51%
Extremely_4 109170/s 3% -- -26% -45% -45% -50%
Ted_var_3 147059/s 39% 35% -- -25% -26% -32%
Extremely_5 196850/s 86% 80% 34% -- -1% -9%
Ted_var_2 199601/s 88% 83% 36% 1% -- -8%
Ted_var_2a 217391/s 105% 99% 48% 10% 9% --
My/Ted's one liner beats all the other variations that protect
the original array quite handily. Ted's cool in place matches
the one liner(ish) and removing the return nets you a small
but not insignificant speedup. My variation 4 just shows the gain
from one less assignment.
Fun Stuff! Doh! last minute change, this variant:
# Extremely_5a 209644/s
sub rev_arr5a {
return [map { ref eq 'ARRAY' ? rev_arr5a($_) : $_ } reverse @{$_
+[0]}];
}
exploits the "no shift" trick to beat even the regular
in place Ted_var_2 by 4%, Extremely_5 by 5%, and comes in about
6% under the in place Ted_var_2a.
Benchmark is sucking my will to live. I'm gonna be here all
night if I don't stop!
--
$you = new YOU;
honk() if $you->love(perl) |