use Perl

Alberto Simões posted up an interesting benchmark illustrating that ~~, the new smart match operator in 5.10, outperforms both grep and List::Util::first() in the "is X in this list" role.

Here's my results:

$ perl5.10.0 bench.plx
Benchmark: timing 100000 iterations of first, grep BLOCK, grep EXPR, ~~...
     first: 23 wallclock secs (22.78 usr +  0.03 sys = 22.81 CPU) @ 4384.04/s (n=100000)
grep BLOCK: 18 wallclock secs (18.48 usr +  0.03 sys = 18.51 CPU) @ 5402.49/s (n=100000)
  grep EXPR: 17 wallclock secs (17.56 usr +  0.03 sys = 17.59 CPU) @ 5685.05/s (n=100000)
        ~~: 10 wallclock secs ( 9.97 usr +  0.01 sys =  9.98 CPU) @ 10020.04/s (n=100000)

What I believe it's illustrating is the Perl optimization rule of thumb that the more work you let the opcodes do, the better. ~~ doesn't have to execute a Perl expression over and over again, it can do that in optimized C.

Here's the benchmark code:

use Benchmark;
use 5.010;
use List::Util qw(first);
 
my @array = map { chr(64+int(rand(26)))."$_" } 1..1000;
my $result;
my $needle;
 
timethese(100_000, {
           'first'   => sub {
               $needle = chr(64+int(rand(26))).int(rand(1000)+1);
               $result = first { $_ eq $needle } @array;
           },
           'grep BLOCK'   => sub {
               $needle = chr(64+int(rand(26))).int(rand(1000)+1);
               $result = grep { $_ eq $needle } @array;
           },
           'grep EXPR'   => sub {
               $needle = chr(64+int(rand(26))).int(rand(1000)+1);
               $result = grep $_ eq $needle, @array;
           },
           '~~' => sub {
               $needle = chr(64+int(rand(26))).int(rand(1000)+1);
               $result = $needle ~~ @array;
           }
});