very important update: Please see Re^4: promoting array to a hash by BrowserUk for why the following code is horrifically wrong. Of course, that said, it requires one very simple s!my!our! to correct.

I know that the map vs. slice benchmark has been done before, but just to do it again as a reminder :) 

#!perl -w

use strict;
use Benchmark ':all';

my @unsorted = map {
    join('', map { ('a'..'z','A'..'Z',0..9)[rand 62] } 1..50)
} 1..5000;

sub uniq_dragonchild { my %x; @x{@_} = @_; values %x }
sub uniq_BrowserUk { my %x; @x{@_} = (); keys %x }
sub uniq_Zaxo { keys %{ { map { $_ => undef } @_ } } }

cmpthese(
    timethese(-60, {
        uniq_dragonchild => 'my @x = uniq_dragonchild(@unsorted)',
        uniq_BrowserUk   => 'my @x = uniq_BrowserUk(@unsorted)',
        uniq_Zaxo        => 'my @x = uniq_Zaxo(@unsorted)'
    } )
);

__END__
C:\>uniq.pl
Benchmark: running uniq_BrowserUk, uniq_Zaxo, uniq_dragonchild for at 
+least 60 C
PU seconds...
uniq_BrowserUk: 64 wallclock secs (63.19 usr +  0.02 sys = 63.20 CPU) 
+@ 421025.4
1/s (n=26610069)
 uniq_Zaxo: 59 wallclock secs (60.08 usr +  0.03 sys = 60.11 CPU) @ 18
+6939.31/s
(n=11237109)
uniq_dragonchild: 64 wallclock secs (63.05 usr +  0.02 sys = 63.06 CPU
+) @ 399674
.64/s (n=25204682)
                     Rate        uniq_Zaxo uniq_dragonchild   uniq_Bro
+wserUk
uniq_Zaxo        186939/s               --             -53%           
+  -56%
uniq_dragonchild 399675/s             114%               --           
+   -5%
uniq_BrowserUk   421025/s             125%               5%           
+    --

[download]

In reply to Re^3: promoting array to a hash by saskaqueer
in thread promoting array to a hash by sleepingsquirrel

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