json_ordered.pl

use strict;
use Tie::IxHash;
use JSON::PP;

# magic start

my $obj_parser_sub = \&JSON::PP::object;
*JSON::PP::object = sub {
	tie my %obj, 'Tie::IxHash';
	$obj_parser_sub->(\%obj);
};

# magic end

use Data::Dumper;

my $res = decode_json('{"a":1,"b":2,"c":3}');
print Dumper $res;

$res->{b} = 'xx';
print encode_json($res), "\n";