benchmark of JSON::XS encoding with ascii.

js.pl

use strict;
use warnings;
use JSON::XS;
use Encode;
use Encode::JavaScript::UCS;
use Benchmark;

my $data = { text => "Foo[\x{2028}]Bar" };
my $xs = JSON::XS->new;
my $xsa = $xs->ascii;

timethese(500000, {
		'JSON::XS ascii encoding'          => '&test1;',
		'JSON::XS(ascii) encoding'         => '&test2;',
		'Encode::JavaScript::UCS encoding' => '&test3;',
}); 

sub test1 { $xs->ascii->encode($data) }
sub test2 { $xsa->encode($data) }
sub test3 { encode( 'JavaScript-UCS', $xs->encode($data) ) };

#Benchmark: timing 500000 iterations of Encode::JavaScript::UCS encoding, JSON::XS ascii encoding, JSON::XS(ascii) encoding...
#Encode::JavaScript::UCS encoding: 31 wallclock secs (30.98 usr +  0.02 sys = 31.00 CPU) @ 16129.55/s (n=500000)
#JSON::XS ascii encoding:  3 wallclock secs ( 2.76 usr +  0.00 sys =  2.76 CPU) @ 180831.83/s (n=500000)
#JSON::XS(ascii) encoding:  2 wallclock secs ( 2.16 usr +  0.00 sys =  2.16 CPU) @ 231803.43/s (n=500000)