my %hash; @hash{ @array } = 0 .. $#array;
####
#!/usr/bin/env perl
use strict;
use warnings;
use Benchmark qw(:all);
my @array=qw(a b c d e f g h);
sub original {
my %hash;
for (my $idx=0; $idx<@array; $idx++) { $hash{$array[$idx]} = $idx;}
}
sub variation1 {
my %hash;
@hash{ @array } = 0 .. $#array;
}
sub variation2 {
my %hash = map { $array[$_] => $_ } 0..$#array;
}
sub variation3 {
my $idx = 0;
my %hash = map { $_ => $idx++ } @array;
}
cmpthese(-10, {
'original' => sub{
original()
},
'variation1' => sub{
variation1()
},
'variation2' => sub{
variation2()
},
'variation3' => sub{
variation3()
},
});
##
##
Rate variation2 variation3 original variation1
variation2 142570/s -- -15% -35% -49%
variation3 168018/s 18% -- -24% -40%
original 220185/s 54% 31% -- -21%
variation1 279147/s 96% 66% 27% --