package # This is JSON::backportPP

    JSON::backportPP56;

use 5.006;

use strict;

my @properties;

$JSON::PP56::VERSION = '1.08';

BEGIN {

    sub utf8::is_utf8 {

        my $len =  length $_[0]; # char length

        {

            use bytes; #  byte length;

            return $len != length $_[0]; # if !=, UTF8-flagged on.

        }

    }

    sub utf8::upgrade {

        ; # noop;

    }

    sub utf8::downgrade ($;$) {

        return 1 unless ( utf8::is_utf8( $_[0] ) );

        if ( _is_valid_utf8( $_[0] ) ) {

            my $downgrade;

            for my $c ( unpack( "U*", $_[0] ) ) {

                if ( $c < 256 ) {

                    $downgrade .= pack("C", $c);

                }

                else {

                    $downgrade .= pack("U", $c);

                }

            }

            $_[0] = $downgrade;

            return 1;

        }

        else {

            Carp::croak("Wide character in subroutine entry") unless ( $_[1] );

            0;

        }

    }

    sub utf8::encode ($) { # UTF8 flag off

        if ( utf8::is_utf8( $_[0] ) ) {

            $_[0] = pack( "C*", unpack( "C*", $_[0] ) );

        }

        else {

            $_[0] = pack( "U*", unpack( "C*", $_[0] ) );

            $_[0] = pack( "C*", unpack( "C*", $_[0] ) );

        }

    }

    sub utf8::decode ($) { # UTF8 flag on

        if ( _is_valid_utf8( $_[0] ) ) {

            utf8::downgrade( $_[0] );

            $_[0] = pack( "U*", unpack( "U*", $_[0] ) );

        }

    }

    *JSON::PP::JSON_PP_encode_ascii      = \&_encode_ascii;

    *JSON::PP::JSON_PP_encode_latin1     = \&_encode_latin1;

    *JSON::PP::JSON_PP_decode_surrogates = \&JSON::PP::_decode_surrogates;

    *JSON::PP::JSON_PP_decode_unicode    = \&JSON::PP::_decode_unicode;

    unless ( defined &B::SVp_NOK ) { # missing in B module.

        eval q{ sub B::SVp_NOK () { 0x02000000; } };

    }

}

sub _encode_ascii {

    join('',

        map {

            $_ <= 127 ?

                chr($_) :

            $_ <= 65535 ?

                sprintf('\u%04x', $_) : sprintf('\u%x\u%x', JSON::PP::_encode_surrogates($_));

        } _unpack_emu($_[0])

    );

}

sub _encode_latin1 {

    join('',

        map {

            $_ <= 255 ?

                chr($_) :

            $_ <= 65535 ?

                sprintf('\u%04x', $_) : sprintf('\u%x\u%x', JSON::PP::_encode_surrogates($_));

        } _unpack_emu($_[0])

    );

}

sub _unpack_emu { # for Perl 5.6 unpack warnings

    return   !utf8::is_utf8($_[0]) ? unpack('C*', $_[0]) 

           : _is_valid_utf8($_[0]) ? unpack('U*', $_[0])

           : unpack('C*', $_[0]);

}

sub _is_valid_utf8 {

    my $str = $_[0];

    my $is_utf8;

    while ($str =~ /(?:

          (

             [\x00-\x7F]

            |[\xC2-\xDF][\x80-\xBF]

            |[\xE0][\xA0-\xBF][\x80-\xBF]

            |[\xE1-\xEC][\x80-\xBF][\x80-\xBF]

            |[\xED][\x80-\x9F][\x80-\xBF]

            |[\xEE-\xEF][\x80-\xBF][\x80-\xBF]

            |[\xF0][\x90-\xBF][\x80-\xBF][\x80-\xBF]

            |[\xF1-\xF3][\x80-\xBF][\x80-\xBF][\x80-\xBF]

            |[\xF4][\x80-\x8F][\x80-\xBF][\x80-\xBF]

          )

        | (.)

    )/xg)

    {

        if (defined $1) {

            $is_utf8 = 1 if (!defined $is_utf8);

        }

        else {

            $is_utf8 = 0 if (!defined $is_utf8);

            if ($is_utf8) { # eventually, not utf8

                return;

            }

        }

    }

    return $is_utf8;

}

1;

__END__

=pod

=head1 NAME

JSON::PP56 - Helper module in using JSON::PP in Perl 5.6

=head1 DESCRIPTION

JSON::PP calls internally.

=head1 AUTHOR

Makamaka Hannyaharamitu, E<lt>makamaka[at]cpan.orgE<gt>

=head1 COPYRIGHT AND LICENSE

Copyright 2007-2012 by Makamaka Hannyaharamitu

This library is free software; you can redistribute it and/or modify

it under the same terms as Perl itself. 

=cut