texlive[45724] Master: add JSON module to TeXLive (plus sources)
commits+preining at tug.org
commits+preining at tug.org
Thu Nov 9 05:18:40 CET 2017
Revision: 45724
http://tug.org/svn/texlive?view=revision&revision=45724
Author: preining
Date: 2017-11-09 05:18:40 +0100 (Thu, 09 Nov 2017)
Log Message:
-----------
add JSON module to TeXLive (plus sources)
Added Paths:
-----------
trunk/Master/source/JSON-2.94.tar.gz
trunk/Master/tlpkg/TeXLive/JSON/
trunk/Master/tlpkg/TeXLive/JSON/backportPP/
trunk/Master/tlpkg/TeXLive/JSON/backportPP/Boolean.pm
trunk/Master/tlpkg/TeXLive/JSON/backportPP/Compat5005.pm
trunk/Master/tlpkg/TeXLive/JSON/backportPP/Compat5006.pm
trunk/Master/tlpkg/TeXLive/JSON/backportPP.pm
trunk/Master/tlpkg/TeXLive/JSON.pm
Added: trunk/Master/source/JSON-2.94.tar.gz
===================================================================
(Binary files differ)
Index: trunk/Master/source/JSON-2.94.tar.gz
===================================================================
--- trunk/Master/source/JSON-2.94.tar.gz 2017-11-09 03:24:09 UTC (rev 45723)
+++ trunk/Master/source/JSON-2.94.tar.gz 2017-11-09 04:18:40 UTC (rev 45724)
Property changes on: trunk/Master/source/JSON-2.94.tar.gz
___________________________________________________________________
Added: svn:mime-type
## -0,0 +1 ##
+application/octet-stream
\ No newline at end of property
Added: trunk/Master/tlpkg/TeXLive/JSON/backportPP/Boolean.pm
===================================================================
--- trunk/Master/tlpkg/TeXLive/JSON/backportPP/Boolean.pm (rev 0)
+++ trunk/Master/tlpkg/TeXLive/JSON/backportPP/Boolean.pm 2017-11-09 04:18:40 UTC (rev 45724)
@@ -0,0 +1,36 @@
+package # This is JSON::backportPP
+ JSON::PP::Boolean;
+
+use strict;
+use overload (
+ "0+" => sub { ${$_[0]} },
+ "++" => sub { $_[0] = ${$_[0]} + 1 },
+ "--" => sub { $_[0] = ${$_[0]} - 1 },
+ fallback => 1,
+);
+
+$JSON::backportPP::Boolean::VERSION = '2.94';
+
+1;
+
+__END__
+
+=head1 NAME
+
+JSON::PP::Boolean - dummy module providing JSON::PP::Boolean
+
+=head1 SYNOPSIS
+
+ # do not "use" yourself
+
+=head1 DESCRIPTION
+
+This module exists only to provide overload resolution for Storable and similar modules. See
+L<JSON::PP> for more info about this class.
+
+=head1 AUTHOR
+
+This idea is from L<JSON::XS::Boolean> written by Marc Lehmann <schmorp[at]schmorp.de>
+
+=cut
+
Property changes on: trunk/Master/tlpkg/TeXLive/JSON/backportPP/Boolean.pm
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: trunk/Master/tlpkg/TeXLive/JSON/backportPP/Compat5005.pm
===================================================================
--- trunk/Master/tlpkg/TeXLive/JSON/backportPP/Compat5005.pm (rev 0)
+++ trunk/Master/tlpkg/TeXLive/JSON/backportPP/Compat5005.pm 2017-11-09 04:18:40 UTC (rev 45724)
@@ -0,0 +1,131 @@
+package # This is JSON::backportPP
+ JSON::backportPP5005;
+
+use 5.005;
+use strict;
+
+my @properties;
+
+$JSON::PP5005::VERSION = '1.10';
+
+BEGIN {
+
+ sub utf8::is_utf8 {
+ 0; # It is considered that UTF8 flag off for Perl 5.005.
+ }
+
+ sub utf8::upgrade {
+ }
+
+ sub utf8::downgrade {
+ 1; # must always return true.
+ }
+
+ sub utf8::encode {
+ }
+
+ sub utf8::decode {
+ }
+
+ *JSON::PP::JSON_PP_encode_ascii = \&_encode_ascii;
+ *JSON::PP::JSON_PP_encode_latin1 = \&_encode_latin1;
+ *JSON::PP::JSON_PP_decode_surrogates = \&_decode_surrogates;
+ *JSON::PP::JSON_PP_decode_unicode = \&_decode_unicode;
+
+ # missing in B module.
+ sub B::SVp_IOK () { 0x01000000; }
+ sub B::SVp_NOK () { 0x02000000; }
+ sub B::SVp_POK () { 0x04000000; }
+
+ $INC{'bytes.pm'} = 1; # dummy
+}
+
+
+
+sub _encode_ascii {
+ join('', map { $_ <= 127 ? chr($_) : sprintf('\u%04x', $_) } unpack('C*', $_[0]) );
+}
+
+
+sub _encode_latin1 {
+ join('', map { chr($_) } unpack('C*', $_[0]) );
+}
+
+
+sub _decode_surrogates { # from http://homepage1.nifty.com/nomenclator/unicode/ucs_utf.htm
+ my $uni = 0x10000 + (hex($_[0]) - 0xD800) * 0x400 + (hex($_[1]) - 0xDC00); # from perlunicode
+ my $bit = unpack('B32', pack('N', $uni));
+
+ if ( $bit =~ /^00000000000(...)(......)(......)(......)$/ ) {
+ my ($w, $x, $y, $z) = ($1, $2, $3, $4);
+ return pack('B*', sprintf('11110%s10%s10%s10%s', $w, $x, $y, $z));
+ }
+ else {
+ Carp::croak("Invalid surrogate pair");
+ }
+}
+
+
+sub _decode_unicode {
+ my ($u) = @_;
+ my ($utf8bit);
+
+ if ( $u =~ /^00([89a-f][0-9a-f])$/i ) { # 0x80-0xff
+ return pack( 'H2', $1 );
+ }
+
+ my $bit = unpack("B*", pack("H*", $u));
+
+ if ( $bit =~ /^00000(.....)(......)$/ ) {
+ $utf8bit = sprintf('110%s10%s', $1, $2);
+ }
+ elsif ( $bit =~ /^(....)(......)(......)$/ ) {
+ $utf8bit = sprintf('1110%s10%s10%s', $1, $2, $3);
+ }
+ else {
+ Carp::croak("Invalid escaped unicode");
+ }
+
+ return pack('B*', $utf8bit);
+}
+
+
+sub JSON::PP::incr_text {
+ $_[0]->{_incr_parser} ||= JSON::PP::IncrParser->new;
+
+ if ( $_[0]->{_incr_parser}->{incr_parsing} ) {
+ Carp::croak("incr_text can not be called when the incremental parser already started parsing");
+ }
+
+ $_[0]->{_incr_parser}->{incr_text} = $_[1] if ( @_ > 1 );
+ $_[0]->{_incr_parser}->{incr_text};
+}
+
+
+1;
+__END__
+
+=pod
+
+=head1 NAME
+
+JSON::PP5005 - Helper module in using JSON::PP in Perl 5.005
+
+=head1 DESCRIPTION
+
+JSON::PP calls internally.
+
+=head1 AUTHOR
+
+Makamaka Hannyaharamitu, E<lt>makamaka[at]cpan.orgE<gt>
+
+
+=head1 COPYRIGHT AND LICENSE
+
+Copyright 2007-2012 by Makamaka Hannyaharamitu
+
+This library is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself.
+
+=cut
+
Property changes on: trunk/Master/tlpkg/TeXLive/JSON/backportPP/Compat5005.pm
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: trunk/Master/tlpkg/TeXLive/JSON/backportPP/Compat5006.pm
===================================================================
--- trunk/Master/tlpkg/TeXLive/JSON/backportPP/Compat5006.pm (rev 0)
+++ trunk/Master/tlpkg/TeXLive/JSON/backportPP/Compat5006.pm 2017-11-09 04:18:40 UTC (rev 45724)
@@ -0,0 +1,173 @@
+package # This is JSON::backportPP
+ JSON::backportPP56;
+
+use 5.006;
+use strict;
+
+my @properties;
+
+$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 $is_utf8;
+}
+
+
+1;
+__END__
+
+=pod
+
+=head1 NAME
+
+JSON::PP56 - Helper module in using JSON::PP in Perl 5.6
+
+=head1 DESCRIPTION
+
+JSON::PP calls internally.
+
+=head1 AUTHOR
+
+Makamaka Hannyaharamitu, E<lt>makamaka[at]cpan.orgE<gt>
+
+
+=head1 COPYRIGHT AND LICENSE
+
+Copyright 2007-2012 by Makamaka Hannyaharamitu
+
+This library is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself.
+
+=cut
+
Property changes on: trunk/Master/tlpkg/TeXLive/JSON/backportPP/Compat5006.pm
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: trunk/Master/tlpkg/TeXLive/JSON/backportPP.pm
===================================================================
--- trunk/Master/tlpkg/TeXLive/JSON/backportPP.pm (rev 0)
+++ trunk/Master/tlpkg/TeXLive/JSON/backportPP.pm 2017-11-09 04:18:40 UTC (rev 45724)
@@ -0,0 +1,2854 @@
+package # This is JSON::backportPP
+ JSON::PP;
+
+# JSON-2.0
+
+use 5.005;
+use strict;
+
+use Exporter ();
+BEGIN { @JSON::backportPP::ISA = ('Exporter') }
+
+use overload ();
+use JSON::backportPP::Boolean;
+
+use Carp ();
+#use Devel::Peek;
+
+$JSON::backportPP::VERSION = '2.94';
+
+ at JSON::PP::EXPORT = qw(encode_json decode_json from_json to_json);
+
+# instead of hash-access, i tried index-access for speed.
+# but this method is not faster than what i expected. so it will be changed.
+
+use constant P_ASCII => 0;
+use constant P_LATIN1 => 1;
+use constant P_UTF8 => 2;
+use constant P_INDENT => 3;
+use constant P_CANONICAL => 4;
+use constant P_SPACE_BEFORE => 5;
+use constant P_SPACE_AFTER => 6;
+use constant P_ALLOW_NONREF => 7;
+use constant P_SHRINK => 8;
+use constant P_ALLOW_BLESSED => 9;
+use constant P_CONVERT_BLESSED => 10;
+use constant P_RELAXED => 11;
+
+use constant P_LOOSE => 12;
+use constant P_ALLOW_BIGNUM => 13;
+use constant P_ALLOW_BAREKEY => 14;
+use constant P_ALLOW_SINGLEQUOTE => 15;
+use constant P_ESCAPE_SLASH => 16;
+use constant P_AS_NONBLESSED => 17;
+
+use constant P_ALLOW_UNKNOWN => 18;
+
+use constant OLD_PERL => $] < 5.008 ? 1 : 0;
+use constant USE_B => 0;
+
+BEGIN {
+if (USE_B) {
+ require B;
+}
+}
+
+BEGIN {
+ my @xs_compati_bit_properties = qw(
+ latin1 ascii utf8 indent canonical space_before space_after allow_nonref shrink
+ allow_blessed convert_blessed relaxed allow_unknown
+ );
+ my @pp_bit_properties = qw(
+ allow_singlequote allow_bignum loose
+ allow_barekey escape_slash as_nonblessed
+ );
+
+ # Perl version check, Unicode handling is enabled?
+ # Helper module sets @JSON::PP::_properties.
+ if ( OLD_PERL ) {
+ my $helper = $] >= 5.006 ? 'JSON::backportPP::Compat5006' : 'JSON::backportPP::Compat5005';
+ eval qq| require $helper |;
+ if ($@) { Carp::croak $@; }
+ }
+
+ for my $name (@xs_compati_bit_properties, @pp_bit_properties) {
+ my $property_id = 'P_' . uc($name);
+
+ eval qq/
+ sub $name {
+ my \$enable = defined \$_[1] ? \$_[1] : 1;
+
+ if (\$enable) {
+ \$_[0]->{PROPS}->[$property_id] = 1;
+ }
+ else {
+ \$_[0]->{PROPS}->[$property_id] = 0;
+ }
+
+ \$_[0];
+ }
+
+ sub get_$name {
+ \$_[0]->{PROPS}->[$property_id] ? 1 : '';
+ }
+ /;
+ }
+
+}
+
+
+
+# Functions
+
+my $JSON; # cache
+
+sub encode_json ($) { # encode
+ ($JSON ||= __PACKAGE__->new->utf8)->encode(@_);
+}
+
+
+sub decode_json { # decode
+ ($JSON ||= __PACKAGE__->new->utf8)->decode(@_);
+}
+
+# Obsoleted
+
+sub to_json($) {
+ Carp::croak ("JSON::PP::to_json has been renamed to encode_json.");
+}
+
+
+sub from_json($) {
+ Carp::croak ("JSON::PP::from_json has been renamed to decode_json.");
+}
+
+
+# Methods
+
+sub new {
+ my $class = shift;
+ my $self = {
+ max_depth => 512,
+ max_size => 0,
+ indent_length => 3,
+ };
+
+ bless $self, $class;
+}
+
+
+sub encode {
+ return $_[0]->PP_encode_json($_[1]);
+}
+
+
+sub decode {
+ return $_[0]->PP_decode_json($_[1], 0x00000000);
+}
+
+
+sub decode_prefix {
+ return $_[0]->PP_decode_json($_[1], 0x00000001);
+}
+
+
+# accessor
+
+
+# pretty printing
+
+sub pretty {
+ my ($self, $v) = @_;
+ my $enable = defined $v ? $v : 1;
+
+ if ($enable) { # indent_length(3) for JSON::XS compatibility
+ $self->indent(1)->space_before(1)->space_after(1);
+ }
+ else {
+ $self->indent(0)->space_before(0)->space_after(0);
+ }
+
+ $self;
+}
+
+# etc
+
+sub max_depth {
+ my $max = defined $_[1] ? $_[1] : 0x80000000;
+ $_[0]->{max_depth} = $max;
+ $_[0];
+}
+
+
+sub get_max_depth { $_[0]->{max_depth}; }
+
+
+sub max_size {
+ my $max = defined $_[1] ? $_[1] : 0;
+ $_[0]->{max_size} = $max;
+ $_[0];
+}
+
+
+sub get_max_size { $_[0]->{max_size}; }
+
+
+sub filter_json_object {
+ if (defined $_[1] and ref $_[1] eq 'CODE') {
+ $_[0]->{cb_object} = $_[1];
+ } else {
+ delete $_[0]->{cb_object};
+ }
+ $_[0]->{F_HOOK} = ($_[0]->{cb_object} or $_[0]->{cb_sk_object}) ? 1 : 0;
+ $_[0];
+}
+
+sub filter_json_single_key_object {
+ if (@_ == 1 or @_ > 3) {
+ Carp::croak("Usage: JSON::PP::filter_json_single_key_object(self, key, callback = undef)");
+ }
+ if (defined $_[2] and ref $_[2] eq 'CODE') {
+ $_[0]->{cb_sk_object}->{$_[1]} = $_[2];
+ } else {
+ delete $_[0]->{cb_sk_object}->{$_[1]};
+ delete $_[0]->{cb_sk_object} unless %{$_[0]->{cb_sk_object} || {}};
+ }
+ $_[0]->{F_HOOK} = ($_[0]->{cb_object} or $_[0]->{cb_sk_object}) ? 1 : 0;
+ $_[0];
+}
+
+sub indent_length {
+ if (!defined $_[1] or $_[1] > 15 or $_[1] < 0) {
+ Carp::carp "The acceptable range of indent_length() is 0 to 15.";
+ }
+ else {
+ $_[0]->{indent_length} = $_[1];
+ }
+ $_[0];
+}
+
+sub get_indent_length {
+ $_[0]->{indent_length};
+}
+
+sub sort_by {
+ $_[0]->{sort_by} = defined $_[1] ? $_[1] : 1;
+ $_[0];
+}
+
+sub allow_bigint {
+ Carp::carp("allow_bigint() is obsoleted. use allow_bignum() instead.");
+ $_[0]->allow_bignum;
+}
+
+###############################
+
+###
+### Perl => JSON
+###
+
+
+{ # Convert
+
+ my $max_depth;
+ my $indent;
+ my $ascii;
+ my $latin1;
+ my $utf8;
+ my $space_before;
+ my $space_after;
+ my $canonical;
+ my $allow_blessed;
+ my $convert_blessed;
+
+ my $indent_length;
+ my $escape_slash;
+ my $bignum;
+ my $as_nonblessed;
+
+ my $depth;
+ my $indent_count;
+ my $keysort;
+
+
+ sub PP_encode_json {
+ my $self = shift;
+ my $obj = shift;
+
+ $indent_count = 0;
+ $depth = 0;
+
+ my $props = $self->{PROPS};
+
+ ($ascii, $latin1, $utf8, $indent, $canonical, $space_before, $space_after, $allow_blessed,
+ $convert_blessed, $escape_slash, $bignum, $as_nonblessed)
+ = @{$props}[P_ASCII .. P_SPACE_AFTER, P_ALLOW_BLESSED, P_CONVERT_BLESSED,
+ P_ESCAPE_SLASH, P_ALLOW_BIGNUM, P_AS_NONBLESSED];
+
+ ($max_depth, $indent_length) = @{$self}{qw/max_depth indent_length/};
+
+ $keysort = $canonical ? sub { $a cmp $b } : undef;
+
+ if ($self->{sort_by}) {
+ $keysort = ref($self->{sort_by}) eq 'CODE' ? $self->{sort_by}
+ : $self->{sort_by} =~ /\D+/ ? $self->{sort_by}
+ : sub { $a cmp $b };
+ }
+
+ encode_error("hash- or arrayref expected (not a simple scalar, use allow_nonref to allow this)")
+ if(!ref $obj and !$props->[ P_ALLOW_NONREF ]);
+
+ my $str = $self->object_to_json($obj);
+
+ $str .= "\n" if ( $indent ); # JSON::XS 2.26 compatible
+
+ unless ($ascii or $latin1 or $utf8) {
+ utf8::upgrade($str);
+ }
+
+ if ($props->[ P_SHRINK ]) {
+ utf8::downgrade($str, 1);
+ }
+
+ return $str;
+ }
+
+
+ sub object_to_json {
+ my ($self, $obj) = @_;
+ my $type = ref($obj);
+
+ if($type eq 'HASH'){
+ return $self->hash_to_json($obj);
+ }
+ elsif($type eq 'ARRAY'){
+ return $self->array_to_json($obj);
+ }
+ elsif ($type) { # blessed object?
+ if (blessed($obj)) {
+
+ return $self->value_to_json($obj) if ( $obj->isa('JSON::PP::Boolean') );
+
+ if ( $convert_blessed and $obj->can('TO_JSON') ) {
+ my $result = $obj->TO_JSON();
+ if ( defined $result and ref( $result ) ) {
+ if ( refaddr( $obj ) eq refaddr( $result ) ) {
+ encode_error( sprintf(
+ "%s::TO_JSON method returned same object as was passed instead of a new one",
+ ref $obj
+ ) );
+ }
+ }
+
+ return $self->object_to_json( $result );
+ }
+
+ return "$obj" if ( $bignum and _is_bignum($obj) );
+
+ if ($allow_blessed) {
+ return $self->blessed_to_json($obj) if ($as_nonblessed); # will be removed.
+ return 'null';
+ }
+ encode_error( sprintf("encountered object '%s', but neither allow_blessed "
+ . "nor convert_blessed settings are enabled", $obj)
+ );
+ }
+ else {
+ return $self->value_to_json($obj);
+ }
+ }
+ else{
+ return $self->value_to_json($obj);
+ }
+ }
+
+
+ sub hash_to_json {
+ my ($self, $obj) = @_;
+ my @res;
+
+ encode_error("json text or perl structure exceeds maximum nesting level (max_depth set too low?)")
+ if (++$depth > $max_depth);
+
+ my ($pre, $post) = $indent ? $self->_up_indent() : ('', '');
+ my $del = ($space_before ? ' ' : '') . ':' . ($space_after ? ' ' : '');
+
+ for my $k ( _sort( $obj ) ) {
+ if ( OLD_PERL ) { utf8::decode($k) } # key for Perl 5.6 / be optimized
+ push @res, $self->string_to_json( $k )
+ . $del
+ . ( ref $obj->{$k} ? $self->object_to_json( $obj->{$k} ) : $self->value_to_json( $obj->{$k} ) );
+ }
+
+ --$depth;
+ $self->_down_indent() if ($indent);
+
+ return '{}' unless @res;
+ return '{' . $pre . join( ",$pre", @res ) . $post . '}';
+ }
+
+
+ sub array_to_json {
+ my ($self, $obj) = @_;
+ my @res;
+
+ encode_error("json text or perl structure exceeds maximum nesting level (max_depth set too low?)")
+ if (++$depth > $max_depth);
+
+ my ($pre, $post) = $indent ? $self->_up_indent() : ('', '');
+
+ for my $v (@$obj){
+ push @res, ref($v) ? $self->object_to_json($v) : $self->value_to_json($v);
+ }
+
+ --$depth;
+ $self->_down_indent() if ($indent);
+
+ return '[]' unless @res;
+ return '[' . $pre . join( ",$pre", @res ) . $post . ']';
+ }
+
+ sub _looks_like_number {
+ my $value = shift;
+ if (USE_B) {
+ my $b_obj = B::svref_2object(\$value);
+ my $flags = $b_obj->FLAGS;
+ return 1 if $flags & ( B::SVp_IOK() | B::SVp_NOK() ) and !( $flags & B::SVp_POK() );
+ return;
+ } else {
+ no warnings 'numeric';
+ # detect numbers
+ # string & "" -> ""
+ # number & "" -> 0 (with warning)
+ # nan and inf can detect as numbers, so check with * 0
+ return unless length((my $dummy = "") & $value);
+ return unless 0 + $value eq $value;
+ return 1 if $value * 0 == 0;
+ return -1; # inf/nan
+ }
+ }
+
+ sub value_to_json {
+ my ($self, $value) = @_;
+
+ return 'null' if(!defined $value);
+
+ my $type = ref($value);
+
+ if (!$type) {
+ if (_looks_like_number($value)) {
+ return $value;
+ }
+ return $self->string_to_json($value);
+ }
+ elsif( blessed($value) and $value->isa('JSON::PP::Boolean') ){
+ return $$value == 1 ? 'true' : 'false';
+ }
+ else {
+ if ((overload::StrVal($value) =~ /=(\w+)/)[0]) {
+ return $self->value_to_json("$value");
+ }
+
+ if ($type eq 'SCALAR' and defined $$value) {
+ return $$value eq '1' ? 'true'
+ : $$value eq '0' ? 'false'
+ : $self->{PROPS}->[ P_ALLOW_UNKNOWN ] ? 'null'
+ : encode_error("cannot encode reference to scalar");
+ }
+
+ if ( $self->{PROPS}->[ P_ALLOW_UNKNOWN ] ) {
+ return 'null';
+ }
+ else {
+ if ( $type eq 'SCALAR' or $type eq 'REF' ) {
+ encode_error("cannot encode reference to scalar");
+ }
+ else {
+ encode_error("encountered $value, but JSON can only represent references to arrays or hashes");
+ }
+ }
+
+ }
+ }
+
+
+ my %esc = (
+ "\n" => '\n',
+ "\r" => '\r',
+ "\t" => '\t',
+ "\f" => '\f',
+ "\b" => '\b',
+ "\"" => '\"',
+ "\\" => '\\\\',
+ "\'" => '\\\'',
+ );
+
+
+ sub string_to_json {
+ my ($self, $arg) = @_;
+
+ $arg =~ s/([\x22\x5c\n\r\t\f\b])/$esc{$1}/g;
+ $arg =~ s/\//\\\//g if ($escape_slash);
+ $arg =~ s/([\x00-\x08\x0b\x0e-\x1f])/'\\u00' . unpack('H2', $1)/eg;
+
+ if ($ascii) {
+ $arg = JSON_PP_encode_ascii($arg);
+ }
+
+ if ($latin1) {
+ $arg = JSON_PP_encode_latin1($arg);
+ }
+
+ if ($utf8) {
+ utf8::encode($arg);
+ }
+
+ return '"' . $arg . '"';
+ }
+
+
+ sub blessed_to_json {
+ my $reftype = reftype($_[1]) || '';
+ if ($reftype eq 'HASH') {
+ return $_[0]->hash_to_json($_[1]);
+ }
+ elsif ($reftype eq 'ARRAY') {
+ return $_[0]->array_to_json($_[1]);
+ }
+ else {
+ return 'null';
+ }
+ }
+
+
+ sub encode_error {
+ my $error = shift;
+ Carp::croak "$error";
+ }
+
+
+ sub _sort {
+ defined $keysort ? (sort $keysort (keys %{$_[0]})) : keys %{$_[0]};
+ }
+
+
+ sub _up_indent {
+ my $self = shift;
+ my $space = ' ' x $indent_length;
+
+ my ($pre,$post) = ('','');
+
+ $post = "\n" . $space x $indent_count;
+
+ $indent_count++;
+
+ $pre = "\n" . $space x $indent_count;
+
+ return ($pre,$post);
+ }
+
+
+ sub _down_indent { $indent_count--; }
+
+
+ sub PP_encode_box {
+ {
+ depth => $depth,
+ indent_count => $indent_count,
+ };
+ }
+
+} # Convert
+
+
+sub _encode_ascii {
+ join('',
+ map {
+ $_ <= 127 ?
+ chr($_) :
+ $_ <= 65535 ?
+ sprintf('\u%04x', $_) : sprintf('\u%x\u%x', _encode_surrogates($_));
+ } unpack('U*', $_[0])
+ );
+}
+
+
+sub _encode_latin1 {
+ join('',
+ map {
+ $_ <= 255 ?
+ chr($_) :
+ $_ <= 65535 ?
+ sprintf('\u%04x', $_) : sprintf('\u%x\u%x', _encode_surrogates($_));
+ } unpack('U*', $_[0])
+ );
+}
+
+
+sub _encode_surrogates { # from perlunicode
+ my $uni = $_[0] - 0x10000;
+ return ($uni / 0x400 + 0xD800, $uni % 0x400 + 0xDC00);
+}
+
+
+sub _is_bignum {
+ $_[0]->isa('Math::BigInt') or $_[0]->isa('Math::BigFloat');
+}
+
+
+
+#
+# JSON => Perl
+#
+
+my $max_intsize;
+
+BEGIN {
+ my $checkint = 1111;
+ for my $d (5..64) {
+ $checkint .= 1;
+ my $int = eval qq| $checkint |;
+ if ($int =~ /[eE]/) {
+ $max_intsize = $d - 1;
+ last;
+ }
+ }
+}
+
+{ # PARSE
+
+ my %escapes = ( # by Jeremy Muhlich <jmuhlich [at] bitflood.org>
+ b => "\x8",
+ t => "\x9",
+ n => "\xA",
+ f => "\xC",
+ r => "\xD",
+ '\\' => '\\',
+ '"' => '"',
+ '/' => '/',
+ );
+
+ my $text; # json data
+ my $at; # offset
+ my $ch; # first character
+ my $len; # text length (changed according to UTF8 or NON UTF8)
+ # INTERNAL
+ my $depth; # nest counter
+ my $encoding; # json text encoding
+ my $is_valid_utf8; # temp variable
+ my $utf8_len; # utf8 byte length
+ # FLAGS
+ my $utf8; # must be utf8
+ my $max_depth; # max nest number of objects and arrays
+ my $max_size;
+ my $relaxed;
+ my $cb_object;
+ my $cb_sk_object;
+
+ my $F_HOOK;
+
+ my $allow_bignum; # using Math::BigInt/BigFloat
+ my $singlequote; # loosely quoting
+ my $loose; #
+ my $allow_barekey; # bareKey
+
+ sub _detect_utf_encoding {
+ my $text = shift;
+ my @octets = unpack('C4', $text);
+ return 'unknown' unless defined $octets[3];
+ return ( $octets[0] and $octets[1]) ? 'UTF-8'
+ : (!$octets[0] and $octets[1]) ? 'UTF-16BE'
+ : (!$octets[0] and !$octets[1]) ? 'UTF-32BE'
+ : ( $octets[2] ) ? 'UTF-16LE'
+ : (!$octets[2] ) ? 'UTF-32LE'
+ : 'unknown';
+ }
+
+ sub PP_decode_json {
+ my ($self, $want_offset);
+
+ ($self, $text, $want_offset) = @_;
+
+ ($at, $ch, $depth) = (0, '', 0);
+
+ if ( !defined $text or ref $text ) {
+ decode_error("malformed JSON string, neither array, object, number, string or atom");
+ }
+
+ my $props = $self->{PROPS};
+
+ ($utf8, $relaxed, $loose, $allow_bignum, $allow_barekey, $singlequote)
+ = @{$props}[P_UTF8, P_RELAXED, P_LOOSE .. P_ALLOW_SINGLEQUOTE];
+
+ if ( $utf8 ) {
+ $encoding = _detect_utf_encoding($text);
+ if ($encoding ne 'UTF-8' and $encoding ne 'unknown') {
+ require Encode;
+ Encode::from_to($text, $encoding, 'utf-8');
+ } else {
+ utf8::downgrade( $text, 1 ) or Carp::croak("Wide character in subroutine entry");
+ }
+ }
+ else {
+ utf8::upgrade( $text );
+ utf8::encode( $text );
+ }
+
+ $len = length $text;
+
+ ($max_depth, $max_size, $cb_object, $cb_sk_object, $F_HOOK)
+ = @{$self}{qw/max_depth max_size cb_object cb_sk_object F_HOOK/};
+
+ if ($max_size > 1) {
+ use bytes;
+ my $bytes = length $text;
+ decode_error(
+ sprintf("attempted decode of JSON text of %s bytes size, but max_size is set to %s"
+ , $bytes, $max_size), 1
+ ) if ($bytes > $max_size);
+ }
+
+ white(); # remove head white space
+
+ decode_error("malformed JSON string, neither array, object, number, string or atom") unless defined $ch; # Is there a first character for JSON structure?
+
+ my $result = value();
+
+ if ( !$props->[ P_ALLOW_NONREF ] and !ref $result ) {
+ decode_error(
+ 'JSON text must be an object or array (but found number, string, true, false or null,'
+ . ' use allow_nonref to allow this)', 1);
+ }
+
+ Carp::croak('something wrong.') if $len < $at; # we won't arrive here.
+
+ my $consumed = defined $ch ? $at - 1 : $at; # consumed JSON text length
+
+ white(); # remove tail white space
+
+ return ( $result, $consumed ) if $want_offset; # all right if decode_prefix
+
+ decode_error("garbage after JSON object") if defined $ch;
+
+ $result;
+ }
+
+
+ sub next_chr {
+ return $ch = undef if($at >= $len);
+ $ch = substr($text, $at++, 1);
+ }
+
+
+ sub value {
+ white();
+ return if(!defined $ch);
+ return object() if($ch eq '{');
+ return array() if($ch eq '[');
+ return string() if($ch eq '"' or ($singlequote and $ch eq "'"));
+ return number() if($ch =~ /[0-9]/ or $ch eq '-');
+ return word();
+ }
+
+ sub string {
+ my $utf16;
+ my $is_utf8;
+
+ ($is_valid_utf8, $utf8_len) = ('', 0);
+
+ my $s = ''; # basically UTF8 flag on
+
+ if($ch eq '"' or ($singlequote and $ch eq "'")){
+ my $boundChar = $ch;
+
+ OUTER: while( defined(next_chr()) ){
+
+ if($ch eq $boundChar){
+ next_chr();
+
+ if ($utf16) {
+ decode_error("missing low surrogate character in surrogate pair");
+ }
+
+ utf8::decode($s) if($is_utf8);
+
+ return $s;
+ }
+ elsif($ch eq '\\'){
+ next_chr();
+ if(exists $escapes{$ch}){
+ $s .= $escapes{$ch};
+ }
+ elsif($ch eq 'u'){ # UNICODE handling
+ my $u = '';
+
+ for(1..4){
+ $ch = next_chr();
+ last OUTER if($ch !~ /[0-9a-fA-F]/);
+ $u .= $ch;
+ }
+
+ # U+D800 - U+DBFF
+ if ($u =~ /^[dD][89abAB][0-9a-fA-F]{2}/) { # UTF-16 high surrogate?
+ $utf16 = $u;
+ }
+ # U+DC00 - U+DFFF
+ elsif ($u =~ /^[dD][c-fC-F][0-9a-fA-F]{2}/) { # UTF-16 low surrogate?
+ unless (defined $utf16) {
+ decode_error("missing high surrogate character in surrogate pair");
+ }
+ $is_utf8 = 1;
+ $s .= JSON_PP_decode_surrogates($utf16, $u) || next;
+ $utf16 = undef;
+ }
+ else {
+ if (defined $utf16) {
+ decode_error("surrogate pair expected");
+ }
+
+ if ( ( my $hex = hex( $u ) ) > 127 ) {
+ $is_utf8 = 1;
+ $s .= JSON_PP_decode_unicode($u) || next;
+ }
+ else {
+ $s .= chr $hex;
+ }
+ }
+
+ }
+ else{
+ unless ($loose) {
+ $at -= 2;
+ decode_error('illegal backslash escape sequence in string');
+ }
+ $s .= $ch;
+ }
+ }
+ else{
+
+ if ( ord $ch > 127 ) {
+ unless( $ch = is_valid_utf8($ch) ) {
+ $at -= 1;
+ decode_error("malformed UTF-8 character in JSON string");
+ }
+ else {
+ $at += $utf8_len - 1;
+ }
+
+ $is_utf8 = 1;
+ }
+
+ if (!$loose) {
+ if ($ch =~ /[\x00-\x1f\x22\x5c]/) { # '/' ok
+ $at--;
+ decode_error('invalid character encountered while parsing JSON string');
+ }
+ }
+
+ $s .= $ch;
+ }
+ }
+ }
+
+ decode_error("unexpected end of string while parsing JSON string");
+ }
+
+
+ sub white {
+ while( defined $ch ){
+ if($ch eq '' or $ch =~ /\A[ \t\r\n]\z/){
+ next_chr();
+ }
+ elsif($relaxed and $ch eq '/'){
+ next_chr();
+ if(defined $ch and $ch eq '/'){
+ 1 while(defined(next_chr()) and $ch ne "\n" and $ch ne "\r");
+ }
+ elsif(defined $ch and $ch eq '*'){
+ next_chr();
+ while(1){
+ if(defined $ch){
+ if($ch eq '*'){
+ if(defined(next_chr()) and $ch eq '/'){
+ next_chr();
+ last;
+ }
+ }
+ else{
+ next_chr();
+ }
+ }
+ else{
+ decode_error("Unterminated comment");
+ }
+ }
+ next;
+ }
+ else{
+ $at--;
+ decode_error("malformed JSON string, neither array, object, number, string or atom");
+ }
+ }
+ else{
+ if ($relaxed and $ch eq '#') { # correctly?
+ pos($text) = $at;
+ $text =~ /\G([^\n]*(?:\r\n|\r|\n|$))/g;
+ $at = pos($text);
+ next_chr;
+ next;
+ }
+
+ last;
+ }
+ }
+ }
+
+
+ sub array {
+ my $a = $_[0] || []; # you can use this code to use another array ref object.
+
+ decode_error('json text or perl structure exceeds maximum nesting level (max_depth set too low?)')
+ if (++$depth > $max_depth);
+
+ next_chr();
+ white();
+
+ if(defined $ch and $ch eq ']'){
+ --$depth;
+ next_chr();
+ return $a;
+ }
+ else {
+ while(defined($ch)){
+ push @$a, value();
+
+ white();
+
+ if (!defined $ch) {
+ last;
+ }
+
+ if($ch eq ']'){
+ --$depth;
+ next_chr();
+ return $a;
+ }
+
+ if($ch ne ','){
+ last;
+ }
+
+ next_chr();
+ white();
+
+ if ($relaxed and $ch eq ']') {
+ --$depth;
+ next_chr();
+ return $a;
+ }
+
+ }
+ }
+
+ $at-- if defined $ch and $ch ne '';
+ decode_error(", or ] expected while parsing array");
+ }
+
+
+ sub object {
+ my $o = $_[0] || {}; # you can use this code to use another hash ref object.
+ my $k;
+
+ decode_error('json text or perl structure exceeds maximum nesting level (max_depth set too low?)')
+ if (++$depth > $max_depth);
+ next_chr();
+ white();
+
+ if(defined $ch and $ch eq '}'){
+ --$depth;
+ next_chr();
+ if ($F_HOOK) {
+ return _json_object_hook($o);
+ }
+ return $o;
+ }
+ else {
+ while (defined $ch) {
+ $k = ($allow_barekey and $ch ne '"' and $ch ne "'") ? bareKey() : string();
+ white();
+
+ if(!defined $ch or $ch ne ':'){
+ $at--;
+ decode_error("':' expected");
+ }
+
+ next_chr();
+ $o->{$k} = value();
+ white();
+
+ last if (!defined $ch);
+
+ if($ch eq '}'){
+ --$depth;
+ next_chr();
+ if ($F_HOOK) {
+ return _json_object_hook($o);
+ }
+ return $o;
+ }
+
+ if($ch ne ','){
+ last;
+ }
+
+ next_chr();
+ white();
+
+ if ($relaxed and $ch eq '}') {
+ --$depth;
+ next_chr();
+ if ($F_HOOK) {
+ return _json_object_hook($o);
+ }
+ return $o;
+ }
+
+ }
+
+ }
+
+ $at-- if defined $ch and $ch ne '';
+ decode_error(", or } expected while parsing object/hash");
+ }
+
+
+ sub bareKey { # doesn't strictly follow Standard ECMA-262 3rd Edition
+ my $key;
+ while($ch =~ /[^\x00-\x23\x25-\x2F\x3A-\x40\x5B-\x5E\x60\x7B-\x7F]/){
+ $key .= $ch;
+ next_chr();
+ }
+ return $key;
+ }
+
+
+ sub word {
+ my $word = substr($text,$at-1,4);
+
+ if($word eq 'true'){
+ $at += 3;
+ next_chr;
+ return $JSON::PP::true;
+ }
+ elsif($word eq 'null'){
+ $at += 3;
+ next_chr;
+ return undef;
+ }
+ elsif($word eq 'fals'){
+ $at += 3;
+ if(substr($text,$at,1) eq 'e'){
+ $at++;
+ next_chr;
+ return $JSON::PP::false;
+ }
+ }
+
+ $at--; # for decode_error report
+
+ decode_error("'null' expected") if ($word =~ /^n/);
+ decode_error("'true' expected") if ($word =~ /^t/);
+ decode_error("'false' expected") if ($word =~ /^f/);
+ decode_error("malformed JSON string, neither array, object, number, string or atom");
+ }
+
+
+ sub number {
+ my $n = '';
+ my $v;
+ my $is_dec;
+ my $is_exp;
+
+ if($ch eq '-'){
+ $n = '-';
+ next_chr;
+ if (!defined $ch or $ch !~ /\d/) {
+ decode_error("malformed number (no digits after initial minus)");
+ }
+ }
+
+ # According to RFC4627, hex or oct digits are invalid.
+ if($ch eq '0'){
+ my $peek = substr($text,$at,1);
+ if($peek =~ /^[0-9a-dfA-DF]/){ # e may be valid (exponential)
+ decode_error("malformed number (leading zero must not be followed by another digit)");
+ }
+ $n .= $ch;
+ next_chr;
+ }
+
+ while(defined $ch and $ch =~ /\d/){
+ $n .= $ch;
+ next_chr;
+ }
+
+ if(defined $ch and $ch eq '.'){
+ $n .= '.';
+ $is_dec = 1;
+
+ next_chr;
+ if (!defined $ch or $ch !~ /\d/) {
+ decode_error("malformed number (no digits after decimal point)");
+ }
+ else {
+ $n .= $ch;
+ }
+
+ while(defined(next_chr) and $ch =~ /\d/){
+ $n .= $ch;
+ }
+ }
+
+ if(defined $ch and ($ch eq 'e' or $ch eq 'E')){
+ $n .= $ch;
+ $is_exp = 1;
+ next_chr;
+
+ if(defined($ch) and ($ch eq '+' or $ch eq '-')){
+ $n .= $ch;
+ next_chr;
+ if (!defined $ch or $ch =~ /\D/) {
+ decode_error("malformed number (no digits after exp sign)");
+ }
+ $n .= $ch;
+ }
+ elsif(defined($ch) and $ch =~ /\d/){
+ $n .= $ch;
+ }
+ else {
+ decode_error("malformed number (no digits after exp sign)");
+ }
+
+ while(defined(next_chr) and $ch =~ /\d/){
+ $n .= $ch;
+ }
+
+ }
+
+ $v .= $n;
+
+ if ($is_dec or $is_exp) {
+ if ($allow_bignum) {
+ require Math::BigFloat;
+ return Math::BigFloat->new($v);
+ }
+ } else {
+ if (length $v > $max_intsize) {
+ if ($allow_bignum) { # from Adam Sussman
+ require Math::BigInt;
+ return Math::BigInt->new($v);
+ }
+ else {
+ return "$v";
+ }
+ }
+ }
+
+ return $is_dec ? $v/1.0 : 0+$v;
+ }
+
+
+ sub is_valid_utf8 {
+
+ $utf8_len = $_[0] =~ /[\x00-\x7F]/ ? 1
+ : $_[0] =~ /[\xC2-\xDF]/ ? 2
+ : $_[0] =~ /[\xE0-\xEF]/ ? 3
+ : $_[0] =~ /[\xF0-\xF4]/ ? 4
+ : 0
+ ;
+
+ return unless $utf8_len;
+
+ my $is_valid_utf8 = substr($text, $at - 1, $utf8_len);
+
+ return ( $is_valid_utf8 =~ /^(?:
+ [\x00-\x7F]
+ |[\xC2-\xDF][\x80-\xBF]
+ |[\xE0][\xA0-\xBF][\x80-\xBF]
+ |[\xE1-\xEC][\x80-\xBF][\x80-\xBF]
+ |[\xED][\x80-\x9F][\x80-\xBF]
+ |[\xEE-\xEF][\x80-\xBF][\x80-\xBF]
+ |[\xF0][\x90-\xBF][\x80-\xBF][\x80-\xBF]
+ |[\xF1-\xF3][\x80-\xBF][\x80-\xBF][\x80-\xBF]
+ |[\xF4][\x80-\x8F][\x80-\xBF][\x80-\xBF]
+ )$/x ) ? $is_valid_utf8 : '';
+ }
+
+
+ sub decode_error {
+ my $error = shift;
+ my $no_rep = shift;
+ my $str = defined $text ? substr($text, $at) : '';
+ my $mess = '';
+ my $type = 'U*';
+
+ if ( OLD_PERL ) {
+ my $type = $] < 5.006 ? 'C*'
+ : utf8::is_utf8( $str ) ? 'U*' # 5.6
+ : 'C*'
+ ;
+ }
+
+ for my $c ( unpack( $type, $str ) ) { # emulate pv_uni_display() ?
+ $mess .= $c == 0x07 ? '\a'
+ : $c == 0x09 ? '\t'
+ : $c == 0x0a ? '\n'
+ : $c == 0x0d ? '\r'
+ : $c == 0x0c ? '\f'
+ : $c < 0x20 ? sprintf('\x{%x}', $c)
+ : $c == 0x5c ? '\\\\'
+ : $c < 0x80 ? chr($c)
+ : sprintf('\x{%x}', $c)
+ ;
+ if ( length $mess >= 20 ) {
+ $mess .= '...';
+ last;
+ }
+ }
+
+ unless ( length $mess ) {
+ $mess = '(end of string)';
+ }
+
+ Carp::croak (
+ $no_rep ? "$error" : "$error, at character offset $at (before \"$mess\")"
+ );
+
+ }
+
+
+ sub _json_object_hook {
+ my $o = $_[0];
+ my @ks = keys %{$o};
+
+ if ( $cb_sk_object and @ks == 1 and exists $cb_sk_object->{ $ks[0] } and ref $cb_sk_object->{ $ks[0] } ) {
+ my @val = $cb_sk_object->{ $ks[0] }->( $o->{$ks[0]} );
+ if (@val == 1) {
+ return $val[0];
+ }
+ }
+
+ my @val = $cb_object->($o) if ($cb_object);
+ if (@val == 0 or @val > 1) {
+ return $o;
+ }
+ else {
+ return $val[0];
+ }
+ }
+
+
+ sub PP_decode_box {
+ {
+ text => $text,
+ at => $at,
+ ch => $ch,
+ len => $len,
+ depth => $depth,
+ encoding => $encoding,
+ is_valid_utf8 => $is_valid_utf8,
+ };
+ }
+
+} # PARSE
+
+
+sub _decode_surrogates { # from perlunicode
+ my $uni = 0x10000 + (hex($_[0]) - 0xD800) * 0x400 + (hex($_[1]) - 0xDC00);
+ my $un = pack('U*', $uni);
+ utf8::encode( $un );
+ return $un;
+}
+
+
+sub _decode_unicode {
+ my $un = pack('U', hex shift);
+ utf8::encode( $un );
+ return $un;
+}
+
+#
+# Setup for various Perl versions (the code from JSON::PP58)
+#
+
+BEGIN {
+
+ unless ( defined &utf8::is_utf8 ) {
+ require Encode;
+ *utf8::is_utf8 = *Encode::is_utf8;
+ }
+
+ if ( !OLD_PERL ) {
+ *JSON::PP::JSON_PP_encode_ascii = \&_encode_ascii;
+ *JSON::PP::JSON_PP_encode_latin1 = \&_encode_latin1;
+ *JSON::PP::JSON_PP_decode_surrogates = \&_decode_surrogates;
+ *JSON::PP::JSON_PP_decode_unicode = \&_decode_unicode;
+
+ if ($] < 5.008003) { # join() in 5.8.0 - 5.8.2 is broken.
+ package # hide from PAUSE
+ JSON::PP;
+ require subs;
+ subs->import('join');
+ eval q|
+ sub join {
+ return '' if (@_ < 2);
+ my $j = shift;
+ my $str = shift;
+ for (@_) { $str .= $j . $_; }
+ return $str;
+ }
+ |;
+ }
+ }
+
+
+ sub JSON::PP::incr_parse {
+ local $Carp::CarpLevel = 1;
+ ( $_[0]->{_incr_parser} ||= JSON::PP::IncrParser->new )->incr_parse( @_ );
+ }
+
+
+ sub JSON::PP::incr_skip {
+ ( $_[0]->{_incr_parser} ||= JSON::PP::IncrParser->new )->incr_skip;
+ }
+
+
+ sub JSON::PP::incr_reset {
+ ( $_[0]->{_incr_parser} ||= JSON::PP::IncrParser->new )->incr_reset;
+ }
+
+ eval q{
+ sub JSON::PP::incr_text : lvalue {
+ $_[0]->{_incr_parser} ||= JSON::PP::IncrParser->new;
+
+ if ( $_[0]->{_incr_parser}->{incr_pos} ) {
+ Carp::croak("incr_text cannot be called when the incremental parser already started parsing");
+ }
+ $_[0]->{_incr_parser}->{incr_text};
+ }
+ } if ( $] >= 5.006 );
+
+} # Setup for various Perl versions (the code from JSON::PP58)
+
+
+###############################
+# Utilities
+#
+
+BEGIN {
+ eval 'require Scalar::Util';
+ unless($@){
+ *JSON::PP::blessed = \&Scalar::Util::blessed;
+ *JSON::PP::reftype = \&Scalar::Util::reftype;
+ *JSON::PP::refaddr = \&Scalar::Util::refaddr;
+ }
+ else{ # This code is from Scalar::Util.
+ # warn $@;
+ eval 'sub UNIVERSAL::a_sub_not_likely_to_be_here { ref($_[0]) }';
+ *JSON::PP::blessed = sub {
+ local($@, $SIG{__DIE__}, $SIG{__WARN__});
+ ref($_[0]) ? eval { $_[0]->a_sub_not_likely_to_be_here } : undef;
+ };
+ require B;
+ my %tmap = qw(
+ B::NULL SCALAR
+ B::HV HASH
+ B::AV ARRAY
+ B::CV CODE
+ B::IO IO
+ B::GV GLOB
+ B::REGEXP REGEXP
+ );
+ *JSON::PP::reftype = sub {
+ my $r = shift;
+
+ return undef unless length(ref($r));
+
+ my $t = ref(B::svref_2object($r));
+
+ return
+ exists $tmap{$t} ? $tmap{$t}
+ : length(ref($$r)) ? 'REF'
+ : 'SCALAR';
+ };
+ *JSON::PP::refaddr = sub {
+ return undef unless length(ref($_[0]));
+
+ my $addr;
+ if(defined(my $pkg = blessed($_[0]))) {
+ $addr .= bless $_[0], 'Scalar::Util::Fake';
+ bless $_[0], $pkg;
+ }
+ else {
+ $addr .= $_[0]
+ }
+
+ $addr =~ /0x(\w+)/;
+ local $^W;
+ #no warnings 'portable';
+ hex($1);
+ }
+ }
+}
+
+
+# shamelessly copied and modified from JSON::XS code.
+
+$JSON::PP::true = do { bless \(my $dummy = 1), "JSON::PP::Boolean" };
+$JSON::PP::false = do { bless \(my $dummy = 0), "JSON::PP::Boolean" };
+
+sub is_bool { defined $_[0] and UNIVERSAL::isa($_[0], "JSON::PP::Boolean"); }
+
+sub true { $JSON::PP::true }
+sub false { $JSON::PP::false }
+sub null { undef; }
+
+###############################
+
+package # hide from PAUSE
+ JSON::PP::IncrParser;
+
+use strict;
+
+use constant INCR_M_WS => 0; # initial whitespace skipping
+use constant INCR_M_STR => 1; # inside string
+use constant INCR_M_BS => 2; # inside backslash
+use constant INCR_M_JSON => 3; # outside anything, count nesting
+use constant INCR_M_C0 => 4;
+use constant INCR_M_C1 => 5;
+
+$JSON::backportPP::IncrParser::VERSION = '1.01';
+
+sub new {
+ my ( $class ) = @_;
+
+ bless {
+ incr_nest => 0,
+ incr_text => undef,
+ incr_pos => 0,
+ incr_mode => 0,
+ }, $class;
+}
+
+
+sub incr_parse {
+ my ( $self, $coder, $text ) = @_;
+
+ $self->{incr_text} = '' unless ( defined $self->{incr_text} );
+
+ if ( defined $text ) {
+ if ( utf8::is_utf8( $text ) and !utf8::is_utf8( $self->{incr_text} ) ) {
+ utf8::upgrade( $self->{incr_text} ) ;
+ utf8::decode( $self->{incr_text} ) ;
+ }
+ $self->{incr_text} .= $text;
+ }
+
+ if ( defined wantarray ) {
+ my $max_size = $coder->get_max_size;
+ my $p = $self->{incr_pos};
+ my @ret;
+ {
+ do {
+ unless ( $self->{incr_nest} <= 0 and $self->{incr_mode} == INCR_M_JSON ) {
+ $self->_incr_parse( $coder );
+
+ if ( $max_size and $self->{incr_pos} > $max_size ) {
+ Carp::croak("attempted decode of JSON text of $self->{incr_pos} bytes size, but max_size is set to $max_size");
+ }
+ unless ( $self->{incr_nest} <= 0 and $self->{incr_mode} == INCR_M_JSON ) {
+ # as an optimisation, do not accumulate white space in the incr buffer
+ if ( $self->{incr_mode} == INCR_M_WS and $self->{incr_pos} ) {
+ $self->{incr_pos} = 0;
+ $self->{incr_text} = '';
+ }
+ last;
+ }
+ }
+
+ my ($obj, $offset) = $coder->PP_decode_json( $self->{incr_text}, 0x00000001 );
+ push @ret, $obj;
+ use bytes;
+ $self->{incr_text} = substr( $self->{incr_text}, $offset || 0 );
+ $self->{incr_pos} = 0;
+ $self->{incr_nest} = 0;
+ $self->{incr_mode} = 0;
+ last unless wantarray;
+ } while ( wantarray );
+ }
+
+ if ( wantarray ) {
+ return @ret;
+ }
+ else { # in scalar context
+ return $ret[0] ? $ret[0] : undef;
+ }
+ }
+}
+
+
+sub _incr_parse {
+ my ($self, $coder) = @_;
+ my $text = $self->{incr_text};
+ my $len = length $text;
+ my $p = $self->{incr_pos};
+
+INCR_PARSE:
+ while ( $len > $p ) {
+ my $s = substr( $text, $p, 1 );
+ last INCR_PARSE unless defined $s;
+ my $mode = $self->{incr_mode};
+
+ if ( $mode == INCR_M_WS ) {
+ while ( $len > $p ) {
+ $s = substr( $text, $p, 1 );
+ last INCR_PARSE unless defined $s;
+ if ( ord($s) > 0x20 ) {
+ if ( $s eq '#' ) {
+ $self->{incr_mode} = INCR_M_C0;
+ redo INCR_PARSE;
+ } else {
+ $self->{incr_mode} = INCR_M_JSON;
+ redo INCR_PARSE;
+ }
+ }
+ $p++;
+ }
+ } elsif ( $mode == INCR_M_BS ) {
+ $p++;
+ $self->{incr_mode} = INCR_M_STR;
+ redo INCR_PARSE;
+ } elsif ( $mode == INCR_M_C0 or $mode == INCR_M_C1 ) {
+ while ( $len > $p ) {
+ $s = substr( $text, $p, 1 );
+ last INCR_PARSE unless defined $s;
+ if ( $s eq "\n" ) {
+ $self->{incr_mode} = $self->{incr_mode} == INCR_M_C0 ? INCR_M_WS : INCR_M_JSON;
+ last;
+ }
+ $p++;
+ }
+ next;
+ } elsif ( $mode == INCR_M_STR ) {
+ while ( $len > $p ) {
+ $s = substr( $text, $p, 1 );
+ last INCR_PARSE unless defined $s;
+ if ( $s eq '"' ) {
+ $p++;
+ $self->{incr_mode} = INCR_M_JSON;
+
+ last INCR_PARSE unless $self->{incr_nest};
+ redo INCR_PARSE;
+ }
+ elsif ( $s eq '\\' ) {
+ $p++;
+ if ( !defined substr($text, $p, 1) ) {
+ $self->{incr_mode} = INCR_M_BS;
+ last INCR_PARSE;
+ }
+ }
+ $p++;
+ }
+ } elsif ( $mode == INCR_M_JSON ) {
+ while ( $len > $p ) {
+ $s = substr( $text, $p++, 1 );
+ if ( $s eq "\x00" ) {
+ $p--;
+ last INCR_PARSE;
+ } elsif ( $s eq "\x09" or $s eq "\x0a" or $s eq "\x0d" or $s eq "\x20" ) {
+ if ( !$self->{incr_nest} ) {
+ $p--; # do not eat the whitespace, let the next round do it
+ last INCR_PARSE;
+ }
+ next;
+ } elsif ( $s eq '"' ) {
+ $self->{incr_mode} = INCR_M_STR;
+ redo INCR_PARSE;
+ } elsif ( $s eq '[' or $s eq '{' ) {
+ if ( ++$self->{incr_nest} > $coder->get_max_depth ) {
+ Carp::croak('json text or perl structure exceeds maximum nesting level (max_depth set too low?)');
+ }
+ next;
+ } elsif ( $s eq ']' or $s eq '}' ) {
+ if ( --$self->{incr_nest} <= 0 ) {
+ last INCR_PARSE;
+ }
+ } elsif ( $s eq '#' ) {
+ $self->{incr_mode} = INCR_M_C1;
+ redo INCR_PARSE;
+ }
+ }
+ }
+ }
+
+ $self->{incr_pos} = $p;
+ $self->{incr_parsing} = $p ? 1 : 0; # for backward compatibility
+}
+
+
+sub incr_text {
+ if ( $_[0]->{incr_pos} ) {
+ Carp::croak("incr_text cannot be called when the incremental parser already started parsing");
+ }
+ $_[0]->{incr_text};
+}
+
+
+sub incr_skip {
+ my $self = shift;
+ $self->{incr_text} = substr( $self->{incr_text}, $self->{incr_pos} );
+ $self->{incr_pos} = 0;
+ $self->{incr_mode} = 0;
+ $self->{incr_nest} = 0;
+}
+
+
+sub incr_reset {
+ my $self = shift;
+ $self->{incr_text} = undef;
+ $self->{incr_pos} = 0;
+ $self->{incr_mode} = 0;
+ $self->{incr_nest} = 0;
+}
+
+###############################
+
+
+1;
+__END__
+=pod
+
+=head1 NAME
+
+JSON::PP - JSON::XS compatible pure-Perl module.
+
+=head1 SYNOPSIS
+
+ use JSON::PP;
+
+ # exported functions, they croak on error
+ # and expect/generate UTF-8
+
+ $utf8_encoded_json_text = encode_json $perl_hash_or_arrayref;
+ $perl_hash_or_arrayref = decode_json $utf8_encoded_json_text;
+
+ # OO-interface
+
+ $json = JSON::PP->new->ascii->pretty->allow_nonref;
+
+ $pretty_printed_json_text = $json->encode( $perl_scalar );
+ $perl_scalar = $json->decode( $json_text );
+
+ # Note that JSON version 2.0 and above will automatically use
+ # JSON::XS or JSON::PP, so you should be able to just:
+
+ use JSON;
+
+
+=head1 VERSION
+
+ 2.91_04
+
+=head1 DESCRIPTION
+
+JSON::PP is a pure perl JSON decoder/encoder (as of RFC4627, which
+we know is obsolete but we still stick to; see below for an option
+to support part of RFC7159), and (almost) compatible to much
+faster L<JSON::XS> written by Marc Lehmann in C. JSON::PP works as
+a fallback module when you use L<JSON> module without having
+installed JSON::XS.
+
+Because of this fallback feature of JSON.pm, JSON::PP tries not to
+be more JavaScript-friendly than JSON::XS (i.e. not to escape extra
+characters such as U+2028 and U+2029 nor support RFC7159/ECMA-404),
+in order for you not to lose such JavaScript-friendliness silently
+when you use JSON.pm and install JSON::XS for speed or by accident.
+If you need JavaScript-friendly RFC7159-compliant pure perl module,
+try L<JSON::Tiny>, which is derived from L<Mojolicious> web
+framework and is also smaller and faster than JSON::PP.
+
+JSON::PP has been in the Perl core since Perl 5.14, mainly for
+CPAN toolchain modules to parse META.json.
+
+=head1 FUNCTIONAL INTERFACE
+
+This section is taken from JSON::XS almost verbatim. C<encode_json>
+and C<decode_json> are exported by default.
+
+=head2 encode_json
+
+ $json_text = encode_json $perl_scalar
+
+Converts the given Perl data structure to a UTF-8 encoded, binary string
+(that is, the string contains octets only). Croaks on error.
+
+This function call is functionally identical to:
+
+ $json_text = JSON::PP->new->utf8->encode($perl_scalar)
+
+Except being faster.
+
+=head2 decode_json
+
+ $perl_scalar = decode_json $json_text
+
+The opposite of C<encode_json>: expects an UTF-8 (binary) string and tries
+to parse that as an UTF-8 encoded JSON text, returning the resulting
+reference. Croaks on error.
+
+This function call is functionally identical to:
+
+ $perl_scalar = JSON::PP->new->utf8->decode($json_text)
+
+Except being faster.
+
+=head2 JSON::PP::is_bool
+
+ $is_boolean = JSON::PP::is_bool($scalar)
+
+Returns true if the passed scalar represents either JSON::PP::true or
+JSON::PP::false, two constants that act like C<1> and C<0> respectively
+and are also used to represent JSON C<true> and C<false> in Perl strings.
+
+See L<MAPPING>, below, for more information on how JSON values are mapped to
+Perl.
+
+=head1 OBJECT-ORIENTED INTERFACE
+
+This section is also taken from JSON::XS.
+
+The object oriented interface lets you configure your own encoding or
+decoding style, within the limits of supported formats.
+
+=head2 new
+
+ $json = JSON::PP->new
+
+Creates a new JSON::PP object that can be used to de/encode JSON
+strings. All boolean flags described below are by default I<disabled>.
+
+The mutators for flags all return the JSON::PP object again and thus calls can
+be chained:
+
+ my $json = JSON::PP->new->utf8->space_after->encode({a => [1,2]})
+ => {"a": [1, 2]}
+
+=head2 ascii
+
+ $json = $json->ascii([$enable])
+
+ $enabled = $json->get_ascii
+
+If C<$enable> is true (or missing), then the C<encode> method will not
+generate characters outside the code range C<0..127> (which is ASCII). Any
+Unicode characters outside that range will be escaped using either a
+single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence,
+as per RFC4627. The resulting encoded JSON text can be treated as a native
+Unicode string, an ascii-encoded, latin1-encoded or UTF-8 encoded string,
+or any other superset of ASCII.
+
+If C<$enable> is false, then the C<encode> method will not escape Unicode
+characters unless required by the JSON syntax or other flags. This results
+in a faster and more compact format.
+
+See also the section I<ENCODING/CODESET FLAG NOTES> later in this document.
+
+The main use for this flag is to produce JSON texts that can be
+transmitted over a 7-bit channel, as the encoded JSON texts will not
+contain any 8 bit characters.
+
+ JSON::PP->new->ascii(1)->encode([chr 0x10401])
+ => ["\ud801\udc01"]
+
+=head2 latin1
+
+ $json = $json->latin1([$enable])
+
+ $enabled = $json->get_latin1
+
+If C<$enable> is true (or missing), then the C<encode> method will encode
+the resulting JSON text as latin1 (or iso-8859-1), escaping any characters
+outside the code range C<0..255>. The resulting string can be treated as a
+latin1-encoded JSON text or a native Unicode string. The C<decode> method
+will not be affected in any way by this flag, as C<decode> by default
+expects Unicode, which is a strict superset of latin1.
+
+If C<$enable> is false, then the C<encode> method will not escape Unicode
+characters unless required by the JSON syntax or other flags.
+
+See also the section I<ENCODING/CODESET FLAG NOTES> later in this document.
+
+The main use for this flag is efficiently encoding binary data as JSON
+text, as most octets will not be escaped, resulting in a smaller encoded
+size. The disadvantage is that the resulting JSON text is encoded
+in latin1 (and must correctly be treated as such when storing and
+transferring), a rare encoding for JSON. It is therefore most useful when
+you want to store data structures known to contain binary data efficiently
+in files or databases, not when talking to other JSON encoders/decoders.
+
+ JSON::PP->new->latin1->encode (["\x{89}\x{abc}"]
+ => ["\x{89}\\u0abc"] # (perl syntax, U+abc escaped, U+89 not)
+
+=head2 utf8
+
+ $json = $json->utf8([$enable])
+
+ $enabled = $json->get_utf8
+
+If C<$enable> is true (or missing), then the C<encode> method will encode
+the JSON result into UTF-8, as required by many protocols, while the
+C<decode> method expects to be handled an UTF-8-encoded string. Please
+note that UTF-8-encoded strings do not contain any characters outside the
+range C<0..255>, they are thus useful for bytewise/binary I/O. In future
+versions, enabling this option might enable autodetection of the UTF-16
+and UTF-32 encoding families, as described in RFC4627.
+
+If C<$enable> is false, then the C<encode> method will return the JSON
+string as a (non-encoded) Unicode string, while C<decode> expects thus a
+Unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs
+to be done yourself, e.g. using the Encode module.
+
+See also the section I<ENCODING/CODESET FLAG NOTES> later in this document.
+
+Example, output UTF-16BE-encoded JSON:
+
+ use Encode;
+ $jsontext = encode "UTF-16BE", JSON::PP->new->encode ($object);
+
+Example, decode UTF-32LE-encoded JSON:
+
+ use Encode;
+ $object = JSON::PP->new->decode (decode "UTF-32LE", $jsontext);
+
+=head2 pretty
+
+ $json = $json->pretty([$enable])
+
+This enables (or disables) all of the C<indent>, C<space_before> and
+C<space_after> (and in the future possibly more) flags in one call to
+generate the most readable (or most compact) form possible.
+
+=head2 indent
+
+ $json = $json->indent([$enable])
+
+ $enabled = $json->get_indent
+
+If C<$enable> is true (or missing), then the C<encode> method will use a multiline
+format as output, putting every array member or object/hash key-value pair
+into its own line, indenting them properly.
+
+If C<$enable> is false, no newlines or indenting will be produced, and the
+resulting JSON text is guaranteed not to contain any C<newlines>.
+
+This setting has no effect when decoding JSON texts.
+
+The default indent space length is three.
+You can use C<indent_length> to change the length.
+
+=head2 space_before
+
+ $json = $json->space_before([$enable])
+
+ $enabled = $json->get_space_before
+
+If C<$enable> is true (or missing), then the C<encode> method will add an extra
+optional space before the C<:> separating keys from values in JSON objects.
+
+If C<$enable> is false, then the C<encode> method will not add any extra
+space at those places.
+
+This setting has no effect when decoding JSON texts. You will also
+most likely combine this setting with C<space_after>.
+
+Example, space_before enabled, space_after and indent disabled:
+
+ {"key" :"value"}
+
+=head2 space_after
+
+ $json = $json->space_after([$enable])
+
+ $enabled = $json->get_space_after
+
+If C<$enable> is true (or missing), then the C<encode> method will add an extra
+optional space after the C<:> separating keys from values in JSON objects
+and extra whitespace after the C<,> separating key-value pairs and array
+members.
+
+If C<$enable> is false, then the C<encode> method will not add any extra
+space at those places.
+
+This setting has no effect when decoding JSON texts.
+
+Example, space_before and indent disabled, space_after enabled:
+
+ {"key": "value"}
+
+=head2 relaxed
+
+ $json = $json->relaxed([$enable])
+
+ $enabled = $json->get_relaxed
+
+If C<$enable> is true (or missing), then C<decode> will accept some
+extensions to normal JSON syntax (see below). C<encode> will not be
+affected in anyway. I<Be aware that this option makes you accept invalid
+JSON texts as if they were valid!>. I suggest only to use this option to
+parse application-specific files written by humans (configuration files,
+resource files etc.)
+
+If C<$enable> is false (the default), then C<decode> will only accept
+valid JSON texts.
+
+Currently accepted extensions are:
+
+=over 4
+
+=item * list items can have an end-comma
+
+JSON I<separates> array elements and key-value pairs with commas. This
+can be annoying if you write JSON texts manually and want to be able to
+quickly append elements, so this extension accepts comma at the end of
+such items not just between them:
+
+ [
+ 1,
+ 2, <- this comma not normally allowed
+ ]
+ {
+ "k1": "v1",
+ "k2": "v2", <- this comma not normally allowed
+ }
+
+=item * shell-style '#'-comments
+
+Whenever JSON allows whitespace, shell-style comments are additionally
+allowed. They are terminated by the first carriage-return or line-feed
+character, after which more white-space and comments are allowed.
+
+ [
+ 1, # this comment not allowed in JSON
+ # neither this one...
+ ]
+
+=item * C-style multiple-line '/* */'-comments (JSON::PP only)
+
+Whenever JSON allows whitespace, C-style multiple-line comments are additionally
+allowed. Everything between C</*> and C<*/> is a comment, after which
+more white-space and comments are allowed.
+
+ [
+ 1, /* this comment not allowed in JSON */
+ /* neither this one... */
+ ]
+
+=item * C++-style one-line '//'-comments (JSON::PP only)
+
+Whenever JSON allows whitespace, C++-style one-line comments are additionally
+allowed. They are terminated by the first carriage-return or line-feed
+character, after which more white-space and comments are allowed.
+
+ [
+ 1, // this comment not allowed in JSON
+ // neither this one...
+ ]
+
+=back
+
+=head2 canonical
+
+ $json = $json->canonical([$enable])
+
+ $enabled = $json->get_canonical
+
+If C<$enable> is true (or missing), then the C<encode> method will output JSON objects
+by sorting their keys. This is adding a comparatively high overhead.
+
+If C<$enable> is false, then the C<encode> method will output key-value
+pairs in the order Perl stores them (which will likely change between runs
+of the same script, and can change even within the same run from 5.18
+onwards).
+
+This option is useful if you want the same data structure to be encoded as
+the same JSON text (given the same overall settings). If it is disabled,
+the same hash might be encoded differently even if contains the same data,
+as key-value pairs have no inherent ordering in Perl.
+
+This setting has no effect when decoding JSON texts.
+
+This setting has currently no effect on tied hashes.
+
+=head2 allow_nonref
+
+ $json = $json->allow_nonref([$enable])
+
+ $enabled = $json->get_allow_nonref
+
+If C<$enable> is true (or missing), then the C<encode> method can convert a
+non-reference into its corresponding string, number or null JSON value,
+which is an extension to RFC4627. Likewise, C<decode> will accept those JSON
+values instead of croaking.
+
+If C<$enable> is false, then the C<encode> method will croak if it isn't
+passed an arrayref or hashref, as JSON texts must either be an object
+or array. Likewise, C<decode> will croak if given something that is not a
+JSON object or array.
+
+Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,
+resulting in an invalid JSON text:
+
+ JSON::PP->new->allow_nonref->encode ("Hello, World!")
+ => "Hello, World!"
+
+=head2 allow_unknown
+
+ $json = $json->allow_unknown ([$enable])
+
+ $enabled = $json->get_allow_unknown
+
+If C<$enable> is true (or missing), then C<encode> will I<not> throw an
+exception when it encounters values it cannot represent in JSON (for
+example, filehandles) but instead will encode a JSON C<null> value. Note
+that blessed objects are not included here and are handled separately by
+c<allow_blessed>.
+
+If C<$enable> is false (the default), then C<encode> will throw an
+exception when it encounters anything it cannot encode as JSON.
+
+This option does not affect C<decode> in any way, and it is recommended to
+leave it off unless you know your communications partner.
+
+=head2 allow_blessed
+
+ $json = $json->allow_blessed([$enable])
+
+ $enabled = $json->get_allow_blessed
+
+See L<OBJECT SERIALISATION> for details.
+
+If C<$enable> is true (or missing), then the C<encode> method will not
+barf when it encounters a blessed reference that it cannot convert
+otherwise. Instead, a JSON C<null> value is encoded instead of the object.
+
+If C<$enable> is false (the default), then C<encode> will throw an
+exception when it encounters a blessed object that it cannot convert
+otherwise.
+
+This setting has no effect on C<decode>.
+
+=head2 convert_blessed
+
+ $json = $json->convert_blessed([$enable])
+
+ $enabled = $json->get_convert_blessed
+
+See L<OBJECT SERIALISATION> for details.
+
+If C<$enable> is true (or missing), then C<encode>, upon encountering a
+blessed object, will check for the availability of the C<TO_JSON> method
+on the object's class. If found, it will be called in scalar context and
+the resulting scalar will be encoded instead of the object.
+
+The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>
+returns other blessed objects, those will be handled in the same
+way. C<TO_JSON> must take care of not causing an endless recursion cycle
+(== crash) in this case. The name of C<TO_JSON> was chosen because other
+methods called by the Perl core (== not by the user of the object) are
+usually in upper case letters and to avoid collisions with any C<to_json>
+function or method.
+
+If C<$enable> is false (the default), then C<encode> will not consider
+this type of conversion.
+
+This setting has no effect on C<decode>.
+
+=head2 filter_json_object
+
+ $json = $json->filter_json_object([$coderef])
+
+When C<$coderef> is specified, it will be called from C<decode> each
+time it decodes a JSON object. The only argument is a reference to the
+newly-created hash. If the code references returns a single scalar (which
+need not be a reference), this value (i.e. a copy of that scalar to avoid
+aliasing) is inserted into the deserialised data structure. If it returns
+an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the
+original deserialised hash will be inserted. This setting can slow down
+decoding considerably.
+
+When C<$coderef> is omitted or undefined, any existing callback will
+be removed and C<decode> will not change the deserialised hash in any
+way.
+
+Example, convert all JSON objects into the integer 5:
+
+ my $js = JSON::PP->new->filter_json_object (sub { 5 });
+ # returns [5]
+ $js->decode ('[{}]'); # the given subroutine takes a hash reference.
+ # throw an exception because allow_nonref is not enabled
+ # so a lone 5 is not allowed.
+ $js->decode ('{"a":1, "b":2}');
+
+=head2 filter_json_single_key_object
+
+ $json = $json->filter_json_single_key_object($key [=> $coderef])
+
+Works remotely similar to C<filter_json_object>, but is only called for
+JSON objects having a single key named C<$key>.
+
+This C<$coderef> is called before the one specified via
+C<filter_json_object>, if any. It gets passed the single value in the JSON
+object. If it returns a single value, it will be inserted into the data
+structure. If it returns nothing (not even C<undef> but the empty list),
+the callback from C<filter_json_object> will be called next, as if no
+single-key callback were specified.
+
+If C<$coderef> is omitted or undefined, the corresponding callback will be
+disabled. There can only ever be one callback for a given key.
+
+As this callback gets called less often then the C<filter_json_object>
+one, decoding speed will not usually suffer as much. Therefore, single-key
+objects make excellent targets to serialise Perl objects into, especially
+as single-key JSON objects are as close to the type-tagged value concept
+as JSON gets (it's basically an ID/VALUE tuple). Of course, JSON does not
+support this in any way, so you need to make sure your data never looks
+like a serialised Perl hash.
+
+Typical names for the single object key are C<__class_whatever__>, or
+C<$__dollars_are_rarely_used__$> or C<}ugly_brace_placement>, or even
+things like C<__class_md5sum(classname)__>, to reduce the risk of clashing
+with real hashes.
+
+Example, decode JSON objects of the form C<< { "__widget__" => <id> } >>
+into the corresponding C<< $WIDGET{<id>} >> object:
+
+ # return whatever is in $WIDGET{5}:
+ JSON::PP
+ ->new
+ ->filter_json_single_key_object (__widget__ => sub {
+ $WIDGET{ $_[0] }
+ })
+ ->decode ('{"__widget__": 5')
+
+ # this can be used with a TO_JSON method in some "widget" class
+ # for serialisation to json:
+ sub WidgetBase::TO_JSON {
+ my ($self) = @_;
+
+ unless ($self->{id}) {
+ $self->{id} = ..get..some..id..;
+ $WIDGET{$self->{id}} = $self;
+ }
+
+ { __widget__ => $self->{id} }
+ }
+
+=head2 shrink
+
+ $json = $json->shrink([$enable])
+
+ $enabled = $json->get_shrink
+
+If C<$enable> is true (or missing), the string returned by C<encode> will
+be shrunk (i.e. downgraded if possible).
+
+The actual definition of what shrink does might change in future versions,
+but it will always try to save space at the expense of time.
+
+If C<$enable> is false, then JSON::PP does nothing.
+
+=head2 max_depth
+
+ $json = $json->max_depth([$maximum_nesting_depth])
+
+ $max_depth = $json->get_max_depth
+
+Sets the maximum nesting level (default C<512>) accepted while encoding
+or decoding. If a higher nesting level is detected in JSON text or a Perl
+data structure, then the encoder and decoder will stop and croak at that
+point.
+
+Nesting level is defined by number of hash- or arrayrefs that the encoder
+needs to traverse to reach a given point or the number of C<{> or C<[>
+characters without their matching closing parenthesis crossed to reach a
+given character in a string.
+
+Setting the maximum depth to one disallows any nesting, so that ensures
+that the object is only a single hash/object or array.
+
+If no argument is given, the highest possible setting will be used, which
+is rarely useful.
+
+See L<JSON::XS/SECURITY CONSIDERATIONS> for more info on why this is useful.
+
+=head2 max_size
+
+ $json = $json->max_size([$maximum_string_size])
+
+ $max_size = $json->get_max_size
+
+Set the maximum length a JSON text may have (in bytes) where decoding is
+being attempted. The default is C<0>, meaning no limit. When C<decode>
+is called on a string that is longer then this many bytes, it will not
+attempt to decode the string but throw an exception. This setting has no
+effect on C<encode> (yet).
+
+If no argument is given, the limit check will be deactivated (same as when
+C<0> is specified).
+
+See L<JSON::XS/SECURITY CONSIDERATIONS> for more info on why this is useful.
+
+=head2 encode
+
+ $json_text = $json->encode($perl_scalar)
+
+Converts the given Perl value or data structure to its JSON
+representation. Croaks on error.
+
+=head2 decode
+
+ $perl_scalar = $json->decode($json_text)
+
+The opposite of C<encode>: expects a JSON text and tries to parse it,
+returning the resulting simple scalar or reference. Croaks on error.
+
+=head2 decode_prefix
+
+ ($perl_scalar, $characters) = $json->decode_prefix($json_text)
+
+This works like the C<decode> method, but instead of raising an exception
+when there is trailing garbage after the first JSON object, it will
+silently stop parsing there and return the number of characters consumed
+so far.
+
+This is useful if your JSON texts are not delimited by an outer protocol
+and you need to know where the JSON text ends.
+
+ JSON::PP->new->decode_prefix ("[1] the tail")
+ => ([1], 3)
+
+=head1 FLAGS FOR JSON::PP ONLY
+
+The following flags and properties are for JSON::PP only. If you use
+any of these, you can't make your application run faster by replacing
+JSON::PP with JSON::XS. If you need these and also speed boost,
+try L<Cpanel::JSON::XS>, a fork of JSON::XS by Reini Urban, which
+supports some of these.
+
+=head2 allow_singlequote
+
+ $json = $json->allow_singlequote([$enable])
+ $enabled = $json->get_allow_singlequote
+
+If C<$enable> is true (or missing), then C<decode> will accept
+invalid JSON texts that contain strings that begin and end with
+single quotation marks. C<encode> will not be affected in anyway.
+I<Be aware that this option makes you accept invalid JSON texts
+as if they were valid!>. I suggest only to use this option to
+parse application-specific files written by humans (configuration
+files, resource files etc.)
+
+If C<$enable> is false (the default), then C<decode> will only accept
+valid JSON texts.
+
+ $json->allow_singlequote->decode(qq|{"foo":'bar'}|);
+ $json->allow_singlequote->decode(qq|{'foo':"bar"}|);
+ $json->allow_singlequote->decode(qq|{'foo':'bar'}|);
+
+=head2 allow_barekey
+
+ $json = $json->allow_barekey([$enable])
+ $enabled = $json->get_allow_barekey
+
+If C<$enable> is true (or missing), then C<decode> will accept
+invalid JSON texts that contain JSON objects whose names don't
+begin and end with quotation marks. C<encode> will not be affected
+in anyway. I<Be aware that this option makes you accept invalid JSON
+texts as if they were valid!>. I suggest only to use this option to
+parse application-specific files written by humans (configuration
+files, resource files etc.)
+
+If C<$enable> is false (the default), then C<decode> will only accept
+valid JSON texts.
+
+ $json->allow_barekey->decode(qq|{foo:"bar"}|);
+
+=head2 allow_bignum
+
+ $json = $json->allow_bignum([$enable])
+ $enabled = $json->get_allow_bignum
+
+If C<$enable> is true (or missing), then C<decode> will convert
+big integers Perl cannot handle as integer into L<Math::BigInt>
+objects and convert floating numbers into L<Math::BigFloat>
+objects. C<encode> will convert C<Math::BigInt> and C<Math::BigFloat>
+objects into JSON numbers.
+
+ $json->allow_nonref->allow_bignum;
+ $bigfloat = $json->decode('2.000000000000000000000000001');
+ print $json->encode($bigfloat);
+ # => 2.000000000000000000000000001
+
+See also L<MAPPING>.
+
+=head2 loose
+
+ $json = $json->loose([$enable])
+ $enabled = $json->get_loose
+
+If C<$enable> is true (or missing), then C<decode> will accept
+invalid JSON texts that contain unescaped [\x00-\x1f\x22\x5c]
+characters. C<encode> will not be affected in anyway.
+I<Be aware that this option makes you accept invalid JSON texts
+as if they were valid!>. I suggest only to use this option to
+parse application-specific files written by humans (configuration
+files, resource files etc.)
+
+If C<$enable> is false (the default), then C<decode> will only accept
+valid JSON texts.
+
+ $json->loose->decode(qq|["abc
+ def"]|);
+
+=head2 escape_slash
+
+ $json = $json->escape_slash([$enable])
+ $enabled = $json->get_escape_slash
+
+If C<$enable> is true (or missing), then C<encode> will explicitly
+escape I<slash> (solidus; C<U+002F>) characters to reduce the risk of
+XSS (cross site scripting) that may be caused by C<< </script> >>
+in a JSON text, with the cost of bloating the size of JSON texts.
+
+This option may be useful when you embed JSON in HTML, but embedding
+arbitrary JSON in HTML (by some HTML template toolkit or by string
+interpolation) is risky in general. You must escape necessary
+characters in correct order, depending on the context.
+
+C<decode> will not be affected in anyway.
+
+=head2 indent_length
+
+ $json = $json->indent_length($number_of_spaces)
+ $length = $json->get_indent_length
+
+This option is only useful when you also enable C<indent> or C<pretty>.
+
+JSON::XS indents with three spaces when you C<encode> (if requested
+by C<indent> or C<pretty>), and the number cannot be changed.
+JSON::PP allows you to change/get the number of indent spaces with these
+mutator/accessor. The default number of spaces is three (the same as
+JSON::XS), and the acceptable range is from C<0> (no indentation;
+it'd be better to disable indentation by C<indent(0)>) to C<15>.
+
+=head2 sort_by
+
+ $json = $json->sort_by($code_ref)
+ $json = $json->sort_by($subroutine_name)
+
+If you just want to sort keys (names) in JSON objects when you
+C<encode>, enable C<canonical> option (see above) that allows you to
+sort object keys alphabetically.
+
+If you do need to sort non-alphabetically for whatever reasons,
+you can give a code reference (or a subroutine name) to C<sort_by>,
+then the argument will be passed to Perl's C<sort> built-in function.
+
+As the sorting is done in the JSON::PP scope, you usually need to
+prepend C<JSON::PP::> to the subroutine name, and the special variables
+C<$a> and C<$b> used in the subrontine used by C<sort> function.
+
+Example:
+
+ my %ORDER = (id => 1, class => 2, name => 3);
+ $json->sort_by(sub {
+ ($ORDER{$JSON::PP::a} // 999) <=> ($ORDER{$JSON::PP::b} // 999)
+ or $JSON::PP::a cmp $JSON::PP::b
+ });
+ print $json->encode([
+ {name => 'CPAN', id => 1, href => 'http://cpan.org'}
+ ]);
+ # [{"id":1,"name":"CPAN","href":"http://cpan.org"}]
+
+Note that C<sort_by> affects all the plain hashes in the data structure.
+If you need finer control, C<tie> necessary hashes with a module that
+implements ordered hash (such as L<Hash::Ordered> and L<Tie::IxHash>).
+C<canonical> and C<sort_by> don't affect the key order in C<tie>d
+hashes.
+
+ use Hash::Ordered;
+ tie my %hash, 'Hash::Ordered',
+ (name => 'CPAN', id => 1, href => 'http://cpan.org');
+ print $json->encode([\%hash]);
+ # [{"name":"CPAN","id":1,"href":"http://cpan.org"}] # order is kept
+
+=head1 INCREMENTAL PARSING
+
+This section is also taken from JSON::XS.
+
+In some cases, there is the need for incremental parsing of JSON
+texts. While this module always has to keep both JSON text and resulting
+Perl data structure in memory at one time, it does allow you to parse a
+JSON stream incrementally. It does so by accumulating text until it has
+a full JSON object, which it then can decode. This process is similar to
+using C<decode_prefix> to see if a full JSON object is available, but
+is much more efficient (and can be implemented with a minimum of method
+calls).
+
+JSON::PP will only attempt to parse the JSON text once it is sure it
+has enough text to get a decisive result, using a very simple but
+truly incremental parser. This means that it sometimes won't stop as
+early as the full parser, for example, it doesn't detect mismatched
+parentheses. The only thing it guarantees is that it starts decoding as
+soon as a syntactically valid JSON text has been seen. This means you need
+to set resource limits (e.g. C<max_size>) to ensure the parser will stop
+parsing in the presence if syntax errors.
+
+The following methods implement this incremental parser.
+
+=head2 incr_parse
+
+ $json->incr_parse( [$string] ) # void context
+
+ $obj_or_undef = $json->incr_parse( [$string] ) # scalar context
+
+ @obj_or_empty = $json->incr_parse( [$string] ) # list context
+
+This is the central parsing function. It can both append new text and
+extract objects from the stream accumulated so far (both of these
+functions are optional).
+
+If C<$string> is given, then this string is appended to the already
+existing JSON fragment stored in the C<$json> object.
+
+After that, if the function is called in void context, it will simply
+return without doing anything further. This can be used to add more text
+in as many chunks as you want.
+
+If the method is called in scalar context, then it will try to extract
+exactly I<one> JSON object. If that is successful, it will return this
+object, otherwise it will return C<undef>. If there is a parse error,
+this method will croak just as C<decode> would do (one can then use
+C<incr_skip> to skip the erroneous part). This is the most common way of
+using the method.
+
+And finally, in list context, it will try to extract as many objects
+from the stream as it can find and return them, or the empty list
+otherwise. For this to work, there must be no separators (other than
+whitespace) between the JSON objects or arrays, instead they must be
+concatenated back-to-back. If an error occurs, an exception will be
+raised as in the scalar context case. Note that in this case, any
+previously-parsed JSON texts will be lost.
+
+Example: Parse some JSON arrays/objects in a given string and return
+them.
+
+ my @objs = JSON::PP->new->incr_parse ("[5][7][1,2]");
+
+=head2 incr_text
+
+ $lvalue_string = $json->incr_text
+
+This method returns the currently stored JSON fragment as an lvalue, that
+is, you can manipulate it. This I<only> works when a preceding call to
+C<incr_parse> in I<scalar context> successfully returned an object. Under
+all other circumstances you must not call this function (I mean it.
+although in simple tests it might actually work, it I<will> fail under
+real world conditions). As a special exception, you can also call this
+method before having parsed anything.
+
+That means you can only use this function to look at or manipulate text
+before or after complete JSON objects, not while the parser is in the
+middle of parsing a JSON object.
+
+This function is useful in two cases: a) finding the trailing text after a
+JSON object or b) parsing multiple JSON objects separated by non-JSON text
+(such as commas).
+
+=head2 incr_skip
+
+ $json->incr_skip
+
+This will reset the state of the incremental parser and will remove
+the parsed text from the input buffer so far. This is useful after
+C<incr_parse> died, in which case the input buffer and incremental parser
+state is left unchanged, to skip the text parsed so far and to reset the
+parse state.
+
+The difference to C<incr_reset> is that only text until the parse error
+occurred is removed.
+
+=head2 incr_reset
+
+ $json->incr_reset
+
+This completely resets the incremental parser, that is, after this call,
+it will be as if the parser had never parsed anything.
+
+This is useful if you want to repeatedly parse JSON objects and want to
+ignore any trailing data, which means you have to reset the parser after
+each successful decode.
+
+=head1 MAPPING
+
+Most of this section is also taken from JSON::XS.
+
+This section describes how JSON::PP maps Perl values to JSON values and
+vice versa. These mappings are designed to "do the right thing" in most
+circumstances automatically, preserving round-tripping characteristics
+(what you put in comes out as something equivalent).
+
+For the more enlightened: note that in the following descriptions,
+lowercase I<perl> refers to the Perl interpreter, while uppercase I<Perl>
+refers to the abstract Perl language itself.
+
+=head2 JSON -> PERL
+
+=over 4
+
+=item object
+
+A JSON object becomes a reference to a hash in Perl. No ordering of object
+keys is preserved (JSON does not preserve object key ordering itself).
+
+=item array
+
+A JSON array becomes a reference to an array in Perl.
+
+=item string
+
+A JSON string becomes a string scalar in Perl - Unicode codepoints in JSON
+are represented by the same codepoints in the Perl string, so no manual
+decoding is necessary.
+
+=item number
+
+A JSON number becomes either an integer, numeric (floating point) or
+string scalar in perl, depending on its range and any fractional parts. On
+the Perl level, there is no difference between those as Perl handles all
+the conversion details, but an integer may take slightly less memory and
+might represent more values exactly than floating point numbers.
+
+If the number consists of digits only, JSON::PP will try to represent
+it as an integer value. If that fails, it will try to represent it as
+a numeric (floating point) value if that is possible without loss of
+precision. Otherwise it will preserve the number as a string value (in
+which case you lose roundtripping ability, as the JSON number will be
+re-encoded to a JSON string).
+
+Numbers containing a fractional or exponential part will always be
+represented as numeric (floating point) values, possibly at a loss of
+precision (in which case you might lose perfect roundtripping ability, but
+the JSON number will still be re-encoded as a JSON number).
+
+Note that precision is not accuracy - binary floating point values cannot
+represent most decimal fractions exactly, and when converting from and to
+floating point, JSON::PP only guarantees precision up to but not including
+the least significant bit.
+
+When C<allow_bignum> is enabled, big integer values and any numeric
+values will be converted into L<Math::BigInt> and L<Math::BigFloat>
+objects respectively, without becoming string scalars or losing
+precision.
+
+=item true, false
+
+These JSON atoms become C<JSON::PP::true> and C<JSON::PP::false>,
+respectively. They are overloaded to act almost exactly like the numbers
+C<1> and C<0>. You can check whether a scalar is a JSON boolean by using
+the C<JSON::PP::is_bool> function.
+
+=item null
+
+A JSON null atom becomes C<undef> in Perl.
+
+=item shell-style comments (C<< # I<text> >>)
+
+As a nonstandard extension to the JSON syntax that is enabled by the
+C<relaxed> setting, shell-style comments are allowed. They can start
+anywhere outside strings and go till the end of the line.
+
+=back
+
+
+=head2 PERL -> JSON
+
+The mapping from Perl to JSON is slightly more difficult, as Perl is a
+truly typeless language, so we can only guess which JSON type is meant by
+a Perl value.
+
+=over 4
+
+=item hash references
+
+Perl hash references become JSON objects. As there is no inherent
+ordering in hash keys (or JSON objects), they will usually be encoded
+in a pseudo-random order. JSON::PP can optionally sort the hash keys
+(determined by the I<canonical> flag and/or I<sort_by> property), so
+the same data structure will serialise to the same JSON text (given
+same settings and version of JSON::PP), but this incurs a runtime
+overhead and is only rarely useful, e.g. when you want to compare some
+JSON text against another for equality.
+
+=item array references
+
+Perl array references become JSON arrays.
+
+=item other references
+
+Other unblessed references are generally not allowed and will cause an
+exception to be thrown, except for references to the integers C<0> and
+C<1>, which get turned into C<false> and C<true> atoms in JSON. You can
+also use C<JSON::PP::false> and C<JSON::PP::true> to improve
+readability.
+
+ to_json [\0, JSON::PP::true] # yields [false,true]
+
+=item JSON::PP::true, JSON::PP::false
+
+These special values become JSON true and JSON false values,
+respectively. You can also use C<\1> and C<\0> directly if you want.
+
+=item JSON::PP::null
+
+This special value becomes JSON null.
+
+=item blessed objects
+
+Blessed objects are not directly representable in JSON, but C<JSON::PP>
+allows various ways of handling objects. See L<OBJECT SERIALISATION>,
+below, for details.
+
+=item simple scalars
+
+Simple Perl scalars (any scalar that is not a reference) are the most
+difficult objects to encode: JSON::PP will encode undefined scalars as
+JSON C<null> values, scalars that have last been used in a string context
+before encoding as JSON strings, and anything else as number value:
+
+ # dump as number
+ encode_json [2] # yields [2]
+ encode_json [-3.0e17] # yields [-3e+17]
+ my $value = 5; encode_json [$value] # yields [5]
+
+ # used as string, so dump as string
+ print $value;
+ encode_json [$value] # yields ["5"]
+
+ # undef becomes null
+ encode_json [undef] # yields [null]
+
+You can force the type to be a string by stringifying it:
+
+ my $x = 3.1; # some variable containing a number
+ "$x"; # stringified
+ $x .= ""; # another, more awkward way to stringify
+ print $x; # perl does it for you, too, quite often
+ # (but for older perls)
+
+You can force the type to be a number by numifying it:
+
+ my $x = "3"; # some variable containing a string
+ $x += 0; # numify it, ensuring it will be dumped as a number
+ $x *= 1; # same thing, the choice is yours.
+
+You cannot currently force the type in other, less obscure, ways.
+
+Note that numerical precision has the same meaning as under Perl (so
+binary to decimal conversion follows the same rules as in Perl, which
+can differ to other languages). Also, your perl interpreter might expose
+extensions to the floating point numbers of your platform, such as
+infinities or NaN's - these cannot be represented in JSON, and it is an
+error to pass those in.
+
+JSON::PP (and JSON::XS) trusts what you pass to C<encode> method
+(or C<encode_json> function) is a clean, validated data structure with
+values that can be represented as valid JSON values only, because it's
+not from an external data source (as opposed to JSON texts you pass to
+C<decode> or C<decode_json>, which JSON::PP considers tainted and
+doesn't trust). As JSON::PP doesn't know exactly what you and consumers
+of your JSON texts want the unexpected values to be (you may want to
+convert them into null, or to stringify them with or without
+normalisation (string representation of infinities/NaN may vary
+depending on platforms), or to croak without conversion), you're advised
+to do what you and your consumers need before you encode, and also not
+to numify values that may start with values that look like a number
+(including infinities/NaN), without validating.
+
+=back
+
+=head2 OBJECT SERIALISATION
+
+As for Perl objects, JSON::PP only supports a pure JSON representation (without the ability to deserialise the object automatically again).
+
+=head3 SERIALISATION
+
+What happens when C<JSON::PP> encounters a Perl object depends on the
+C<allow_blessed>, C<convert_blessed> and C<allow_bignum> settings, which are
+used in this order:
+
+=over 4
+
+=item 1. C<convert_blessed> is enabled and the object has a C<TO_JSON> method.
+
+In this case, the C<TO_JSON> method of the object is invoked in scalar
+context. It must return a single scalar that can be directly encoded into
+JSON. This scalar replaces the object in the JSON text.
+
+For example, the following C<TO_JSON> method will convert all L<URI>
+objects to JSON strings when serialised. The fact that these values
+originally were L<URI> objects is lost.
+
+ sub URI::TO_JSON {
+ my ($uri) = @_;
+ $uri->as_string
+ }
+
+=item 2. C<allow_bignum> is enabled and the object is a C<Math::BigInt> or C<Math::BigFloat>.
+
+The object will be serialised as a JSON number value.
+
+=item 3. C<allow_blessed> is enabled.
+
+The object will be serialised as a JSON null value.
+
+=item 4. none of the above
+
+If none of the settings are enabled or the respective methods are missing,
+C<JSON::PP> throws an exception.
+
+=back
+
+=head1 ENCODING/CODESET FLAG NOTES
+
+This section is taken from JSON::XS.
+
+The interested reader might have seen a number of flags that signify
+encodings or codesets - C<utf8>, C<latin1> and C<ascii>. There seems to be
+some confusion on what these do, so here is a short comparison:
+
+C<utf8> controls whether the JSON text created by C<encode> (and expected
+by C<decode>) is UTF-8 encoded or not, while C<latin1> and C<ascii> only
+control whether C<encode> escapes character values outside their respective
+codeset range. Neither of these flags conflict with each other, although
+some combinations make less sense than others.
+
+Care has been taken to make all flags symmetrical with respect to
+C<encode> and C<decode>, that is, texts encoded with any combination of
+these flag values will be correctly decoded when the same flags are used
+- in general, if you use different flag settings while encoding vs. when
+decoding you likely have a bug somewhere.
+
+Below comes a verbose discussion of these flags. Note that a "codeset" is
+simply an abstract set of character-codepoint pairs, while an encoding
+takes those codepoint numbers and I<encodes> them, in our case into
+octets. Unicode is (among other things) a codeset, UTF-8 is an encoding,
+and ISO-8859-1 (= latin 1) and ASCII are both codesets I<and> encodings at
+the same time, which can be confusing.
+
+=over 4
+
+=item C<utf8> flag disabled
+
+When C<utf8> is disabled (the default), then C<encode>/C<decode> generate
+and expect Unicode strings, that is, characters with high ordinal Unicode
+values (> 255) will be encoded as such characters, and likewise such
+characters are decoded as-is, no changes to them will be done, except
+"(re-)interpreting" them as Unicode codepoints or Unicode characters,
+respectively (to Perl, these are the same thing in strings unless you do
+funny/weird/dumb stuff).
+
+This is useful when you want to do the encoding yourself (e.g. when you
+want to have UTF-16 encoded JSON texts) or when some other layer does
+the encoding for you (for example, when printing to a terminal using a
+filehandle that transparently encodes to UTF-8 you certainly do NOT want
+to UTF-8 encode your data first and have Perl encode it another time).
+
+=item C<utf8> flag enabled
+
+If the C<utf8>-flag is enabled, C<encode>/C<decode> will encode all
+characters using the corresponding UTF-8 multi-byte sequence, and will
+expect your input strings to be encoded as UTF-8, that is, no "character"
+of the input string must have any value > 255, as UTF-8 does not allow
+that.
+
+The C<utf8> flag therefore switches between two modes: disabled means you
+will get a Unicode string in Perl, enabled means you get an UTF-8 encoded
+octet/binary string in Perl.
+
+=item C<latin1> or C<ascii> flags enabled
+
+With C<latin1> (or C<ascii>) enabled, C<encode> will escape characters
+with ordinal values > 255 (> 127 with C<ascii>) and encode the remaining
+characters as specified by the C<utf8> flag.
+
+If C<utf8> is disabled, then the result is also correctly encoded in those
+character sets (as both are proper subsets of Unicode, meaning that a
+Unicode string with all character values < 256 is the same thing as a
+ISO-8859-1 string, and a Unicode string with all character values < 128 is
+the same thing as an ASCII string in Perl).
+
+If C<utf8> is enabled, you still get a correct UTF-8-encoded string,
+regardless of these flags, just some more characters will be escaped using
+C<\uXXXX> then before.
+
+Note that ISO-8859-1-I<encoded> strings are not compatible with UTF-8
+encoding, while ASCII-encoded strings are. That is because the ISO-8859-1
+encoding is NOT a subset of UTF-8 (despite the ISO-8859-1 I<codeset> being
+a subset of Unicode), while ASCII is.
+
+Surprisingly, C<decode> will ignore these flags and so treat all input
+values as governed by the C<utf8> flag. If it is disabled, this allows you
+to decode ISO-8859-1- and ASCII-encoded strings, as both strict subsets of
+Unicode. If it is enabled, you can correctly decode UTF-8 encoded strings.
+
+So neither C<latin1> nor C<ascii> are incompatible with the C<utf8> flag -
+they only govern when the JSON output engine escapes a character or not.
+
+The main use for C<latin1> is to relatively efficiently store binary data
+as JSON, at the expense of breaking compatibility with most JSON decoders.
+
+The main use for C<ascii> is to force the output to not contain characters
+with values > 127, which means you can interpret the resulting string
+as UTF-8, ISO-8859-1, ASCII, KOI8-R or most about any character set and
+8-bit-encoding, and still get the same data structure back. This is useful
+when your channel for JSON transfer is not 8-bit clean or the encoding
+might be mangled in between (e.g. in mail), and works because ASCII is a
+proper subset of most 8-bit and multibyte encodings in use in the world.
+
+=back
+
+=head1 SEE ALSO
+
+The F<json_pp> command line utility for quick experiments.
+
+L<JSON::XS>, L<Cpanel::JSON::XS>, and L<JSON::Tiny> for faster alternatives.
+L<JSON> and L<JSON::MaybeXS> for easy migration.
+
+L<JSON::backportPP::Compat5005> and L<JSON::backportPP::Compat5006> for older perl users.
+
+RFC4627 (L<http://www.ietf.org/rfc/rfc4627.txt>)
+
+=head1 AUTHOR
+
+Makamaka Hannyaharamitu, E<lt>makamaka[at]cpan.orgE<gt>
+
+
+=head1 COPYRIGHT AND LICENSE
+
+Copyright 2007-2016 by Makamaka Hannyaharamitu
+
+This library is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself.
+
+=cut
Property changes on: trunk/Master/tlpkg/TeXLive/JSON/backportPP.pm
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: trunk/Master/tlpkg/TeXLive/JSON.pm
===================================================================
--- trunk/Master/tlpkg/TeXLive/JSON.pm (rev 0)
+++ trunk/Master/tlpkg/TeXLive/JSON.pm 2017-11-09 04:18:40 UTC (rev 45724)
@@ -0,0 +1,1659 @@
+package JSON;
+
+
+use strict;
+use Carp ();
+use Exporter;
+BEGIN { @JSON::ISA = 'Exporter' }
+
+ at JSON::EXPORT = qw(from_json to_json jsonToObj objToJson encode_json decode_json);
+
+BEGIN {
+ $JSON::VERSION = '2.94';
+ $JSON::DEBUG = 0 unless (defined $JSON::DEBUG);
+ $JSON::DEBUG = $ENV{ PERL_JSON_DEBUG } if exists $ENV{ PERL_JSON_DEBUG };
+}
+
+my %RequiredVersion = (
+ 'JSON::PP' => '2.27203',
+ 'JSON::XS' => '2.34',
+);
+
+# XS and PP common methods
+
+my @PublicMethods = qw/
+ ascii latin1 utf8 pretty indent space_before space_after relaxed canonical allow_nonref
+ allow_blessed convert_blessed filter_json_object filter_json_single_key_object
+ shrink max_depth max_size encode decode decode_prefix allow_unknown
+/;
+
+my @Properties = qw/
+ ascii latin1 utf8 indent space_before space_after relaxed canonical allow_nonref
+ allow_blessed convert_blessed shrink max_depth max_size allow_unknown
+/;
+
+my @XSOnlyMethods = qw/allow_tags/; # Currently nothing
+
+my @PPOnlyMethods = qw/
+ indent_length sort_by
+ allow_singlequote allow_bignum loose allow_barekey escape_slash as_nonblessed
+/; # JSON::PP specific
+
+
+# used in _load_xs and _load_pp ($INSTALL_ONLY is not used currently)
+my $_INSTALL_DONT_DIE = 1; # When _load_xs fails to load XS, don't die.
+my $_ALLOW_UNSUPPORTED = 0;
+my $_UNIV_CONV_BLESSED = 0;
+
+
+# Check the environment variable to decide worker module.
+
+unless ($JSON::Backend) {
+ $JSON::DEBUG and Carp::carp("Check used worker module...");
+
+ my $backend = exists $ENV{PERL_JSON_BACKEND} ? $ENV{PERL_JSON_BACKEND} : 1;
+
+ if ($backend eq '1') {
+ $backend = 'JSON::XS,JSON::PP';
+ }
+ elsif ($backend eq '0') {
+ $backend = 'JSON::PP';
+ }
+ elsif ($backend eq '2') {
+ $backend = 'JSON::XS';
+ }
+ $backend =~ s/\s+//g;
+
+ my @backend_modules = split /,/, $backend;
+ while(my $module = shift @backend_modules) {
+ if ($module =~ /JSON::XS/) {
+ _load_xs($module, @backend_modules ? $_INSTALL_DONT_DIE : 0);
+ }
+ elsif ($module =~ /JSON::PP/) {
+ _load_pp($module);
+ }
+ elsif ($module =~ /JSON::backportPP/) {
+ _load_pp($module);
+ }
+ else {
+ Carp::croak "The value of environmental variable 'PERL_JSON_BACKEND' is invalid.";
+ }
+ last if $JSON::Backend;
+ }
+}
+
+
+sub import {
+ my $pkg = shift;
+ my @what_to_export;
+ my $no_export;
+
+ for my $tag (@_) {
+ if ($tag eq '-support_by_pp') {
+ if (!$_ALLOW_UNSUPPORTED++) {
+ JSON::Backend::XS
+ ->support_by_pp(@PPOnlyMethods) if ($JSON::Backend->is_xs);
+ }
+ next;
+ }
+ elsif ($tag eq '-no_export') {
+ $no_export++, next;
+ }
+ elsif ( $tag eq '-convert_blessed_universally' ) {
+ my $org_encode = $JSON::Backend->can('encode');
+ eval q|
+ require B;
+ local $^W;
+ no strict 'refs';
+ *{"${JSON::Backend}\::encode"} = sub {
+ # only works with Perl 5.18+
+ local *UNIVERSAL::TO_JSON = sub {
+ my $b_obj = B::svref_2object( $_[0] );
+ return $b_obj->isa('B::HV') ? { %{ $_[0] } }
+ : $b_obj->isa('B::AV') ? [ @{ $_[0] } ]
+ : undef
+ ;
+ };
+ $org_encode->(@_);
+ };
+ | if ( !$_UNIV_CONV_BLESSED++ );
+ next;
+ }
+ push @what_to_export, $tag;
+ }
+
+ return if ($no_export);
+
+ __PACKAGE__->export_to_level(1, $pkg, @what_to_export);
+}
+
+
+# OBSOLETED
+
+sub jsonToObj {
+ my $alternative = 'from_json';
+ if (defined $_[0] and UNIVERSAL::isa($_[0], 'JSON')) {
+ shift @_; $alternative = 'decode';
+ }
+ Carp::carp "'jsonToObj' will be obsoleted. Please use '$alternative' instead.";
+ return JSON::from_json(@_);
+};
+
+sub objToJson {
+ my $alternative = 'to_json';
+ if (defined $_[0] and UNIVERSAL::isa($_[0], 'JSON')) {
+ shift @_; $alternative = 'encode';
+ }
+ Carp::carp "'objToJson' will be obsoleted. Please use '$alternative' instead.";
+ JSON::to_json(@_);
+};
+
+
+# INTERFACES
+
+sub to_json ($@) {
+ if (
+ ref($_[0]) eq 'JSON'
+ or (@_ > 2 and $_[0] eq 'JSON')
+ ) {
+ Carp::croak "to_json should not be called as a method.";
+ }
+ my $json = JSON->new;
+
+ if (@_ == 2 and ref $_[1] eq 'HASH') {
+ my $opt = $_[1];
+ for my $method (keys %$opt) {
+ $json->$method( $opt->{$method} );
+ }
+ }
+
+ $json->encode($_[0]);
+}
+
+
+sub from_json ($@) {
+ if ( ref($_[0]) eq 'JSON' or $_[0] eq 'JSON' ) {
+ Carp::croak "from_json should not be called as a method.";
+ }
+ my $json = JSON->new;
+
+ if (@_ == 2 and ref $_[1] eq 'HASH') {
+ my $opt = $_[1];
+ for my $method (keys %$opt) {
+ $json->$method( $opt->{$method} );
+ }
+ }
+
+ return $json->decode( $_[0] );
+}
+
+
+
+sub true { $JSON::true }
+
+sub false { $JSON::false }
+
+sub null { undef; }
+
+
+sub require_xs_version { $RequiredVersion{'JSON::XS'}; }
+
+sub backend {
+ my $proto = shift;
+ $JSON::Backend;
+}
+
+#*module = *backend;
+
+
+sub is_xs {
+ return $_[0]->backend->is_xs;
+}
+
+
+sub is_pp {
+ return $_[0]->backend->is_pp;
+}
+
+
+sub pureperl_only_methods { @PPOnlyMethods; }
+
+
+sub property {
+ my ($self, $name, $value) = @_;
+
+ if (@_ == 1) {
+ my %props;
+ for $name (@Properties) {
+ my $method = 'get_' . $name;
+ if ($name eq 'max_size') {
+ my $value = $self->$method();
+ $props{$name} = $value == 1 ? 0 : $value;
+ next;
+ }
+ $props{$name} = $self->$method();
+ }
+ return \%props;
+ }
+ elsif (@_ > 3) {
+ Carp::croak('property() can take only the option within 2 arguments.');
+ }
+ elsif (@_ == 2) {
+ if ( my $method = $self->can('get_' . $name) ) {
+ if ($name eq 'max_size') {
+ my $value = $self->$method();
+ return $value == 1 ? 0 : $value;
+ }
+ $self->$method();
+ }
+ }
+ else {
+ $self->$name($value);
+ }
+
+}
+
+
+
+# INTERNAL
+
+sub __load_xs {
+ my ($module, $opt) = @_;
+
+ $JSON::DEBUG and Carp::carp "Load $module.";
+ my $required_version = $RequiredVersion{$module} || '';
+
+ eval qq|
+ use $module $required_version ();
+ |;
+
+ if ($@) {
+ if (defined $opt and $opt & $_INSTALL_DONT_DIE) {
+ $JSON::DEBUG and Carp::carp "Can't load $module...($@)";
+ return 0;
+ }
+ Carp::croak $@;
+ }
+ $JSON::BackendModuleXS = $module;
+ return 1;
+}
+
+sub _load_xs {
+ my ($module, $opt) = @_;
+ __load_xs($module, $opt) or return;
+
+ my $data = join("", <DATA>); # this code is from Jcode 2.xx.
+ close(DATA);
+ eval $data;
+ JSON::Backend::XS->init($module);
+
+ return 1;
+};
+
+
+sub __load_pp {
+ my ($module, $opt) = @_;
+
+ $JSON::DEBUG and Carp::carp "Load $module.";
+ my $required_version = $RequiredVersion{$module} || '';
+
+ eval qq| use $module $required_version () |;
+
+ if ($@) {
+ if ( $module eq 'JSON::PP' ) {
+ $JSON::DEBUG and Carp::carp "Can't load $module ($@), so try to load JSON::backportPP";
+ $module = 'JSON::backportPP';
+ local $^W; # if PP installed but invalid version, backportPP redefines methods.
+ eval qq| require $module |;
+ }
+ Carp::croak $@ if $@;
+ }
+ $JSON::BackendModulePP = $module;
+ return 1;
+}
+
+sub _load_pp {
+ my ($module, $opt) = @_;
+ __load_pp($module, $opt);
+
+ JSON::Backend::PP->init($module);
+};
+
+#
+# Helper classes for Backend Module (PP)
+#
+
+package JSON::Backend::PP;
+
+sub init {
+ my ($class, $module) = @_;
+
+ # name may vary, but the module should (always) be a JSON::PP
+
+ local $^W;
+ no strict qw(refs); # this routine may be called after JSON::Backend::XS init was called.
+ *{"JSON::decode_json"} = \&{"JSON::PP::decode_json"};
+ *{"JSON::encode_json"} = \&{"JSON::PP::encode_json"};
+ *{"JSON::is_bool"} = \&{"JSON::PP::is_bool"};
+
+ $JSON::true = ${"JSON::PP::true"};
+ $JSON::false = ${"JSON::PP::false"};
+
+ push @JSON::Backend::PP::ISA, 'JSON::PP';
+ push @JSON::ISA, $class;
+ $JSON::Backend = $class;
+ $JSON::BackendModule = $module;
+ ${"$class\::VERSION"} = $module->VERSION;
+
+ for my $method (@XSOnlyMethods) {
+ *{"JSON::$method"} = sub {
+ Carp::carp("$method is not supported in $module.");
+ $_[0];
+ };
+ }
+
+ return 1;
+}
+
+sub is_xs { 0 };
+sub is_pp { 1 };
+
+#
+# To save memory, the below lines are read only when XS backend is used.
+#
+
+package JSON;
+
+1;
+__DATA__
+
+
+#
+# Helper classes for Backend Module (XS)
+#
+
+package JSON::Backend::XS;
+
+sub init {
+ my ($class, $module) = @_;
+
+ local $^W;
+ no strict qw(refs);
+ *{"JSON::decode_json"} = \&{"$module\::decode_json"};
+ *{"JSON::encode_json"} = \&{"$module\::encode_json"};
+ *{"JSON::is_bool"} = \&{"$module\::is_bool"};
+
+ $JSON::true = ${"$module\::true"};
+ $JSON::false = ${"$module\::false"};
+
+ push @JSON::Backend::XS::ISA, $module;
+ push @JSON::ISA, $class;
+ $JSON::Backend = $class;
+ $JSON::BackendModule = $module;
+ ${"$class\::VERSION"} = $module->VERSION;
+
+ if ( $module->VERSION < 3 ) {
+ eval 'package JSON::PP::Boolean';
+ push @{"$module\::Boolean::ISA"}, qw(JSON::PP::Boolean);
+ }
+
+ for my $method (@PPOnlyMethods) {
+ *{"JSON::$method"} = sub {
+ Carp::carp("$method is not supported in $module.");
+ $_[0];
+ };
+ }
+
+ return 1;
+}
+
+sub is_xs { 1 };
+sub is_pp { 0 };
+
+sub support_by_pp {
+ my ($class, @methods) = @_;
+
+ JSON::__load_pp('JSON::PP');
+
+ local $^W;
+ no strict qw(refs);
+
+ for my $method (@methods) {
+ my $pp_method = JSON::PP->can($method) or next;
+ *{"JSON::$method"} = sub {
+ if (!$_[0]->isa('JSON::PP')) {
+ my $xs_self = $_[0];
+ my $pp_self = JSON::PP->new;
+ for (@Properties) {
+ my $getter = "get_$_";
+ $pp_self->$_($xs_self->$getter);
+ }
+ $_[0] = $pp_self;
+ }
+ $pp_method->(@_);
+ };
+ }
+
+ $JSON::DEBUG and Carp::carp("set -support_by_pp mode.");
+}
+
+1;
+__END__
+
+=head1 NAME
+
+JSON - JSON (JavaScript Object Notation) encoder/decoder
+
+=head1 SYNOPSIS
+
+ use JSON; # imports encode_json, decode_json, to_json and from_json.
+
+ # simple and fast interfaces (expect/generate UTF-8)
+
+ $utf8_encoded_json_text = encode_json $perl_hash_or_arrayref;
+ $perl_hash_or_arrayref = decode_json $utf8_encoded_json_text;
+
+ # OO-interface
+
+ $json = JSON->new->allow_nonref;
+
+ $json_text = $json->encode( $perl_scalar );
+ $perl_scalar = $json->decode( $json_text );
+
+ $pretty_printed = $json->pretty->encode( $perl_scalar ); # pretty-printing
+
+=head1 VERSION
+
+ 2.93
+
+=head1 DESCRIPTION
+
+This module is a thin wrapper for L<JSON::XS>-compatible modules with a few
+additional features. All the backend modules convert a Perl data structure
+to a JSON text as of RFC4627 (which we know is obsolete but we still stick
+to; see below for an option to support part of RFC7159) and vice versa.
+This module uses L<JSON::XS> by default, and when JSON::XS is not available,
+this module falls back on L<JSON::PP>, which is in the Perl core since 5.14.
+If JSON::PP is not available either, this module then falls back on
+JSON::backportPP (which is actually JSON::PP in a different .pm file)
+bundled in the same distribution as this module. You can also explicitly
+specify to use L<Cpanel::JSON::XS>, a fork of JSON::XS by Reini Urban.
+
+All these backend modules have slight incompatibilities between them,
+including extra features that other modules don't support, but as long as you
+use only common features (most important ones are described below), migration
+from backend to backend should be reasonably easy. For details, see each
+backend module you use.
+
+=head1 CHOOSING BACKEND
+
+This module respects an environmental variable called C<PERL_JSON_BACKEND>
+when it decides a backend module to use. If this environmental variable is
+not set, it tries to load JSON::XS, and if JSON::XS is not available, it
+falls back on JSON::PP, and then JSON::backportPP if JSON::PP is not available
+either.
+
+If you always don't want it to fall back on pure perl modules, set the
+variable like this (C<export> may be C<setenv>, C<set> and the likes,
+depending on your environment):
+
+ > export PERL_JSON_BACKEND=JSON::XS
+
+If you prefer Cpanel::JSON::XS to JSON::XS, then:
+
+ > export PERL_JSON_BACKEND=Cpanel::JSON::XS,JSON::XS,JSON::PP
+
+You may also want to set this variable at the top of your test files, in order
+not to be bothered with incompatibilities between backends (you need to wrap
+this in C<BEGIN>, and set before actually C<use>-ing JSON module, as it decides
+its backend as soon as it's loaded):
+
+ BEGIN { $ENV{PERL_JSON_BACKEND}='JSON::backportPP'; }
+ use JSON;
+
+=head1 USING OPTIONAL FEATURES
+
+There are a few options you can set when you C<use> this module:
+
+=over
+
+=item -support_by_pp
+
+ BEGIN { $ENV{PERL_JSON_BACKEND} = 'JSON::XS' }
+
+ use JSON -support_by_pp;
+
+ my $json = JSON->new;
+ # escape_slash is for JSON::PP only.
+ $json->allow_nonref->escape_slash->encode("/");
+
+With this option, this module loads its pure perl backend along with
+its XS backend (if available), and lets the XS backend to watch if you set
+a flag only JSON::PP supports. When you do, the internal JSON::XS object
+is replaced with a newly created JSON::PP object with the setting copied
+from the XS object, so that you can use JSON::PP flags (and its slower
+C<decode>/C<encode> methods) from then on. In other words, this is not
+something that allows you to hook JSON::XS to change its behavior while
+keeping its speed. JSON::XS and JSON::PP objects are quite different
+(JSON::XS object is a blessed scalar reference, while JSON::PP object is
+a blessed hash reference), and can't share their internals.
+
+To avoid needless overhead (by copying settings), you are advised not
+to use this option and just to use JSON::PP explicitly when you need
+JSON::PP features.
+
+=item -convert_blessed_universally
+
+ use JSON -convert_blessed_universally;
+
+ my $json = JSON->new->allow_nonref->convert_blessed;
+ my $object = bless {foo => 'bar'}, 'Foo';
+ $json->encode($object); # => {"foo":"bar"}
+
+JSON::XS-compatible backend modules don't encode blessed objects by
+default (except for their boolean values, which are typically blessed
+JSON::PP::Boolean objects). If you need to encode a data structure
+that may contain objects, you usually need to look into the structure
+and replace objects with alternative non-blessed values, or enable
+C<convert_blessed> and provide a C<TO_JSON> method for each object's
+(base) class that may be found in the structure, in order to let the
+methods replace the objects with whatever scalar values the methods
+return.
+
+If you need to serialise data structures that may contain arbitrary
+objects, it's probably better to use other serialisers (such as
+L<Sereal> or L<Storable> for example), but if you do want to use
+this module for that purpose, C<-convert_blessed_universally> option
+may help, which tweaks C<encode> method of the backend to install
+C<UNIVERSAL::TO_JSON> method (locally) before encoding, so that
+all the objects that don't have their own C<TO_JSON> method can
+fall back on the method in the C<UNIVERSAL> namespace. Note that you
+still need to enable C<convert_blessed> flag to actually encode
+objects in a data structure, and C<UNIVERSAL::TO_JSON> method
+installed by this option only converts blessed hash/array references
+into their unblessed clone (including private keys/values that are
+not supposed to be exposed). Other blessed references will be
+converted into null.
+
+This feature is experimental and may be removed in the future.
+
+=item -no_export
+
+When you don't want to import functional interfaces from a module, you
+usually supply C<()> to its C<use> statement.
+
+ use JSON (); # no functional interfaces
+
+If you don't want to import functional interfaces, but you also want to
+use any of the above options, add C<-no_export> to the option list.
+
+ # no functional interfaces, while JSON::PP support is enabled.
+ use JSON -support_by_pp, -no_export;
+
+=back
+
+=head1 FUNCTIONAL INTERFACE
+
+This section is taken from JSON::XS. C<encode_json> and C<decode_json>
+are exported by default.
+
+This module also exports C<to_json> and C<from_json> for backward
+compatibility. These are slower, and may expect/generate different stuff
+from what C<encode_json> and C<decode_json> do, depending on their
+options. It's better just to use Object-Oriented interfaces than using
+these two functions.
+
+=head2 encode_json
+
+ $json_text = encode_json $perl_scalar
+
+Converts the given Perl data structure to a UTF-8 encoded, binary string
+(that is, the string contains octets only). Croaks on error.
+
+This function call is functionally identical to:
+
+ $json_text = JSON->new->utf8->encode($perl_scalar)
+
+Except being faster.
+
+=head2 decode_json
+
+ $perl_scalar = decode_json $json_text
+
+The opposite of C<encode_json>: expects an UTF-8 (binary) string and tries
+to parse that as an UTF-8 encoded JSON text, returning the resulting
+reference. Croaks on error.
+
+This function call is functionally identical to:
+
+ $perl_scalar = JSON->new->utf8->decode($json_text)
+
+Except being faster.
+
+=head2 to_json
+
+ $json_text = to_json($perl_scalar[, $optional_hashref])
+
+Converts the given Perl data structure to a Unicode string by default.
+Croaks on error.
+
+Basically, this function call is functionally identical to:
+
+ $json_text = JSON->new->encode($perl_scalar)
+
+Except being slower.
+
+You can pass an optional hash reference to modify its behavior, but
+that may change what C<to_json> expects/generates (see
+C<ENCODING/CODESET FLAG NOTES> for details).
+
+ $json_text = to_json($perl_scalar, {utf8 => 1, pretty => 1})
+ # => JSON->new->utf8(1)->pretty(1)->encode($perl_scalar)
+
+=head2 from_json
+
+ $perl_scalar = from_json($json_text[, $optional_hashref])
+
+The opposite of C<to_json>: expects a Unicode string and tries
+to parse it, returning the resulting reference. Croaks on error.
+
+Basically, this function call is functionally identical to:
+
+ $perl_scalar = JSON->new->decode($json_text)
+
+You can pass an optional hash reference to modify its behavior, but
+that may change what C<from_json> expects/generates (see
+C<ENCODING/CODESET FLAG NOTES> for details).
+
+ $perl_scalar = from_json($json_text, {utf8 => 1})
+ # => JSON->new->utf8(1)->decode($json_text)
+
+=head2 JSON::is_bool
+
+ $is_boolean = JSON::is_bool($scalar)
+
+Returns true if the passed scalar represents either JSON::true or
+JSON::false, two constants that act like C<1> and C<0> respectively
+and are also used to represent JSON C<true> and C<false> in Perl strings.
+
+See L<MAPPING>, below, for more information on how JSON values are mapped to
+Perl.
+
+=head1 COMMON OBJECT-ORIENTED INTERFACE
+
+This section is also taken from JSON::XS.
+
+The object oriented interface lets you configure your own encoding or
+decoding style, within the limits of supported formats.
+
+=head2 new
+
+ $json = JSON->new
+
+Creates a new JSON::XS-compatible backend object that can be used to de/encode JSON
+strings. All boolean flags described below are by default I<disabled>.
+
+The mutators for flags all return the backend object again and thus calls can
+be chained:
+
+ my $json = JSON->new->utf8->space_after->encode({a => [1,2]})
+ => {"a": [1, 2]}
+
+=head2 ascii
+
+ $json = $json->ascii([$enable])
+
+ $enabled = $json->get_ascii
+
+If C<$enable> is true (or missing), then the C<encode> method will not
+generate characters outside the code range C<0..127> (which is ASCII). Any
+Unicode characters outside that range will be escaped using either a
+single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence,
+as per RFC4627. The resulting encoded JSON text can be treated as a native
+Unicode string, an ascii-encoded, latin1-encoded or UTF-8 encoded string,
+or any other superset of ASCII.
+
+If C<$enable> is false, then the C<encode> method will not escape Unicode
+characters unless required by the JSON syntax or other flags. This results
+in a faster and more compact format.
+
+See also the section I<ENCODING/CODESET FLAG NOTES> later in this document.
+
+The main use for this flag is to produce JSON texts that can be
+transmitted over a 7-bit channel, as the encoded JSON texts will not
+contain any 8 bit characters.
+
+ JSON->new->ascii(1)->encode([chr 0x10401])
+ => ["\ud801\udc01"]
+
+=head2 latin1
+
+ $json = $json->latin1([$enable])
+
+ $enabled = $json->get_latin1
+
+If C<$enable> is true (or missing), then the C<encode> method will encode
+the resulting JSON text as latin1 (or iso-8859-1), escaping any characters
+outside the code range C<0..255>. The resulting string can be treated as a
+latin1-encoded JSON text or a native Unicode string. The C<decode> method
+will not be affected in any way by this flag, as C<decode> by default
+expects Unicode, which is a strict superset of latin1.
+
+If C<$enable> is false, then the C<encode> method will not escape Unicode
+characters unless required by the JSON syntax or other flags.
+
+See also the section I<ENCODING/CODESET FLAG NOTES> later in this document.
+
+The main use for this flag is efficiently encoding binary data as JSON
+text, as most octets will not be escaped, resulting in a smaller encoded
+size. The disadvantage is that the resulting JSON text is encoded
+in latin1 (and must correctly be treated as such when storing and
+transferring), a rare encoding for JSON. It is therefore most useful when
+you want to store data structures known to contain binary data efficiently
+in files or databases, not when talking to other JSON encoders/decoders.
+
+ JSON->new->latin1->encode (["\x{89}\x{abc}"]
+ => ["\x{89}\\u0abc"] # (perl syntax, U+abc escaped, U+89 not)
+
+=head2 utf8
+
+ $json = $json->utf8([$enable])
+
+ $enabled = $json->get_utf8
+
+If C<$enable> is true (or missing), then the C<encode> method will encode
+the JSON result into UTF-8, as required by many protocols, while the
+C<decode> method expects to be handled an UTF-8-encoded string. Please
+note that UTF-8-encoded strings do not contain any characters outside the
+range C<0..255>, they are thus useful for bytewise/binary I/O. In future
+versions, enabling this option might enable autodetection of the UTF-16
+and UTF-32 encoding families, as described in RFC4627.
+
+If C<$enable> is false, then the C<encode> method will return the JSON
+string as a (non-encoded) Unicode string, while C<decode> expects thus a
+Unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs
+to be done yourself, e.g. using the Encode module.
+
+See also the section I<ENCODING/CODESET FLAG NOTES> later in this document.
+
+Example, output UTF-16BE-encoded JSON:
+
+ use Encode;
+ $jsontext = encode "UTF-16BE", JSON->new->encode ($object);
+
+Example, decode UTF-32LE-encoded JSON:
+
+ use Encode;
+ $object = JSON->new->decode (decode "UTF-32LE", $jsontext);
+
+=head2 pretty
+
+ $json = $json->pretty([$enable])
+
+This enables (or disables) all of the C<indent>, C<space_before> and
+C<space_after> (and in the future possibly more) flags in one call to
+generate the most readable (or most compact) form possible.
+
+=head2 indent
+
+ $json = $json->indent([$enable])
+
+ $enabled = $json->get_indent
+
+If C<$enable> is true (or missing), then the C<encode> method will use a multiline
+format as output, putting every array member or object/hash key-value pair
+into its own line, indenting them properly.
+
+If C<$enable> is false, no newlines or indenting will be produced, and the
+resulting JSON text is guaranteed not to contain any C<newlines>.
+
+This setting has no effect when decoding JSON texts.
+
+=head2 space_before
+
+ $json = $json->space_before([$enable])
+
+ $enabled = $json->get_space_before
+
+If C<$enable> is true (or missing), then the C<encode> method will add an extra
+optional space before the C<:> separating keys from values in JSON objects.
+
+If C<$enable> is false, then the C<encode> method will not add any extra
+space at those places.
+
+This setting has no effect when decoding JSON texts. You will also
+most likely combine this setting with C<space_after>.
+
+Example, space_before enabled, space_after and indent disabled:
+
+ {"key" :"value"}
+
+=head2 space_after
+
+ $json = $json->space_after([$enable])
+
+ $enabled = $json->get_space_after
+
+If C<$enable> is true (or missing), then the C<encode> method will add an extra
+optional space after the C<:> separating keys from values in JSON objects
+and extra whitespace after the C<,> separating key-value pairs and array
+members.
+
+If C<$enable> is false, then the C<encode> method will not add any extra
+space at those places.
+
+This setting has no effect when decoding JSON texts.
+
+Example, space_before and indent disabled, space_after enabled:
+
+ {"key": "value"}
+
+=head2 relaxed
+
+ $json = $json->relaxed([$enable])
+
+ $enabled = $json->get_relaxed
+
+If C<$enable> is true (or missing), then C<decode> will accept some
+extensions to normal JSON syntax (see below). C<encode> will not be
+affected in anyway. I<Be aware that this option makes you accept invalid
+JSON texts as if they were valid!>. I suggest only to use this option to
+parse application-specific files written by humans (configuration files,
+resource files etc.)
+
+If C<$enable> is false (the default), then C<decode> will only accept
+valid JSON texts.
+
+Currently accepted extensions are:
+
+=over 4
+
+=item * list items can have an end-comma
+
+JSON I<separates> array elements and key-value pairs with commas. This
+can be annoying if you write JSON texts manually and want to be able to
+quickly append elements, so this extension accepts comma at the end of
+such items not just between them:
+
+ [
+ 1,
+ 2, <- this comma not normally allowed
+ ]
+ {
+ "k1": "v1",
+ "k2": "v2", <- this comma not normally allowed
+ }
+
+=item * shell-style '#'-comments
+
+Whenever JSON allows whitespace, shell-style comments are additionally
+allowed. They are terminated by the first carriage-return or line-feed
+character, after which more white-space and comments are allowed.
+
+ [
+ 1, # this comment not allowed in JSON
+ # neither this one...
+ ]
+
+=back
+
+=head2 canonical
+
+ $json = $json->canonical([$enable])
+
+ $enabled = $json->get_canonical
+
+If C<$enable> is true (or missing), then the C<encode> method will output JSON objects
+by sorting their keys. This is adding a comparatively high overhead.
+
+If C<$enable> is false, then the C<encode> method will output key-value
+pairs in the order Perl stores them (which will likely change between runs
+of the same script, and can change even within the same run from 5.18
+onwards).
+
+This option is useful if you want the same data structure to be encoded as
+the same JSON text (given the same overall settings). If it is disabled,
+the same hash might be encoded differently even if contains the same data,
+as key-value pairs have no inherent ordering in Perl.
+
+This setting has no effect when decoding JSON texts.
+
+This setting has currently no effect on tied hashes.
+
+=head2 allow_nonref
+
+ $json = $json->allow_nonref([$enable])
+
+ $enabled = $json->get_allow_nonref
+
+If C<$enable> is true (or missing), then the C<encode> method can convert a
+non-reference into its corresponding string, number or null JSON value,
+which is an extension to RFC4627. Likewise, C<decode> will accept those JSON
+values instead of croaking.
+
+If C<$enable> is false, then the C<encode> method will croak if it isn't
+passed an arrayref or hashref, as JSON texts must either be an object
+or array. Likewise, C<decode> will croak if given something that is not a
+JSON object or array.
+
+Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,
+resulting in an invalid JSON text:
+
+ JSON->new->allow_nonref->encode ("Hello, World!")
+ => "Hello, World!"
+
+=head2 allow_unknown
+
+ $json = $json->allow_unknown ([$enable])
+
+ $enabled = $json->get_allow_unknown
+
+If C<$enable> is true (or missing), then C<encode> will I<not> throw an
+exception when it encounters values it cannot represent in JSON (for
+example, filehandles) but instead will encode a JSON C<null> value. Note
+that blessed objects are not included here and are handled separately by
+c<allow_nonref>.
+
+If C<$enable> is false (the default), then C<encode> will throw an
+exception when it encounters anything it cannot encode as JSON.
+
+This option does not affect C<decode> in any way, and it is recommended to
+leave it off unless you know your communications partner.
+
+=head2 allow_blessed
+
+ $json = $json->allow_blessed([$enable])
+
+ $enabled = $json->get_allow_blessed
+
+See L<OBJECT SERIALISATION> for details.
+
+If C<$enable> is true (or missing), then the C<encode> method will not
+barf when it encounters a blessed reference that it cannot convert
+otherwise. Instead, a JSON C<null> value is encoded instead of the object.
+
+If C<$enable> is false (the default), then C<encode> will throw an
+exception when it encounters a blessed object that it cannot convert
+otherwise.
+
+This setting has no effect on C<decode>.
+
+=head2 convert_blessed
+
+ $json = $json->convert_blessed([$enable])
+
+ $enabled = $json->get_convert_blessed
+
+See L<OBJECT SERIALISATION> for details.
+
+If C<$enable> is true (or missing), then C<encode>, upon encountering a
+blessed object, will check for the availability of the C<TO_JSON> method
+on the object's class. If found, it will be called in scalar context and
+the resulting scalar will be encoded instead of the object.
+
+The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>
+returns other blessed objects, those will be handled in the same
+way. C<TO_JSON> must take care of not causing an endless recursion cycle
+(== crash) in this case. The name of C<TO_JSON> was chosen because other
+methods called by the Perl core (== not by the user of the object) are
+usually in upper case letters and to avoid collisions with any C<to_json>
+function or method.
+
+If C<$enable> is false (the default), then C<encode> will not consider
+this type of conversion.
+
+This setting has no effect on C<decode>.
+
+=head2 filter_json_object
+
+ $json = $json->filter_json_object([$coderef])
+
+When C<$coderef> is specified, it will be called from C<decode> each
+time it decodes a JSON object. The only argument is a reference to the
+newly-created hash. If the code references returns a single scalar (which
+need not be a reference), this value (i.e. a copy of that scalar to avoid
+aliasing) is inserted into the deserialised data structure. If it returns
+an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the
+original deserialised hash will be inserted. This setting can slow down
+decoding considerably.
+
+When C<$coderef> is omitted or undefined, any existing callback will
+be removed and C<decode> will not change the deserialised hash in any
+way.
+
+Example, convert all JSON objects into the integer 5:
+
+ my $js = JSON->new->filter_json_object (sub { 5 });
+ # returns [5]
+ $js->decode ('[{}]'); # the given subroutine takes a hash reference.
+ # throw an exception because allow_nonref is not enabled
+ # so a lone 5 is not allowed.
+ $js->decode ('{"a":1, "b":2}');
+
+=head2 filter_json_single_key_object
+
+ $json = $json->filter_json_single_key_object($key [=> $coderef])
+
+Works remotely similar to C<filter_json_object>, but is only called for
+JSON objects having a single key named C<$key>.
+
+This C<$coderef> is called before the one specified via
+C<filter_json_object>, if any. It gets passed the single value in the JSON
+object. If it returns a single value, it will be inserted into the data
+structure. If it returns nothing (not even C<undef> but the empty list),
+the callback from C<filter_json_object> will be called next, as if no
+single-key callback were specified.
+
+If C<$coderef> is omitted or undefined, the corresponding callback will be
+disabled. There can only ever be one callback for a given key.
+
+As this callback gets called less often then the C<filter_json_object>
+one, decoding speed will not usually suffer as much. Therefore, single-key
+objects make excellent targets to serialise Perl objects into, especially
+as single-key JSON objects are as close to the type-tagged value concept
+as JSON gets (it's basically an ID/VALUE tuple). Of course, JSON does not
+support this in any way, so you need to make sure your data never looks
+like a serialised Perl hash.
+
+Typical names for the single object key are C<__class_whatever__>, or
+C<$__dollars_are_rarely_used__$> or C<}ugly_brace_placement>, or even
+things like C<__class_md5sum(classname)__>, to reduce the risk of clashing
+with real hashes.
+
+Example, decode JSON objects of the form C<< { "__widget__" => <id> } >>
+into the corresponding C<< $WIDGET{<id>} >> object:
+
+ # return whatever is in $WIDGET{5}:
+ JSON
+ ->new
+ ->filter_json_single_key_object (__widget__ => sub {
+ $WIDGET{ $_[0] }
+ })
+ ->decode ('{"__widget__": 5')
+
+ # this can be used with a TO_JSON method in some "widget" class
+ # for serialisation to json:
+ sub WidgetBase::TO_JSON {
+ my ($self) = @_;
+
+ unless ($self->{id}) {
+ $self->{id} = ..get..some..id..;
+ $WIDGET{$self->{id}} = $self;
+ }
+
+ { __widget__ => $self->{id} }
+ }
+
+=head2 max_depth
+
+ $json = $json->max_depth([$maximum_nesting_depth])
+
+ $max_depth = $json->get_max_depth
+
+Sets the maximum nesting level (default C<512>) accepted while encoding
+or decoding. If a higher nesting level is detected in JSON text or a Perl
+data structure, then the encoder and decoder will stop and croak at that
+point.
+
+Nesting level is defined by number of hash- or arrayrefs that the encoder
+needs to traverse to reach a given point or the number of C<{> or C<[>
+characters without their matching closing parenthesis crossed to reach a
+given character in a string.
+
+Setting the maximum depth to one disallows any nesting, so that ensures
+that the object is only a single hash/object or array.
+
+If no argument is given, the highest possible setting will be used, which
+is rarely useful.
+
+=head2 max_size
+
+ $json = $json->max_size([$maximum_string_size])
+
+ $max_size = $json->get_max_size
+
+Set the maximum length a JSON text may have (in bytes) where decoding is
+being attempted. The default is C<0>, meaning no limit. When C<decode>
+is called on a string that is longer then this many bytes, it will not
+attempt to decode the string but throw an exception. This setting has no
+effect on C<encode> (yet).
+
+If no argument is given, the limit check will be deactivated (same as when
+C<0> is specified).
+
+=head2 encode
+
+ $json_text = $json->encode($perl_scalar)
+
+Converts the given Perl value or data structure to its JSON
+representation. Croaks on error.
+
+=head2 decode
+
+ $perl_scalar = $json->decode($json_text)
+
+The opposite of C<encode>: expects a JSON text and tries to parse it,
+returning the resulting simple scalar or reference. Croaks on error.
+
+=head2 decode_prefix
+
+ ($perl_scalar, $characters) = $json->decode_prefix($json_text)
+
+This works like the C<decode> method, but instead of raising an exception
+when there is trailing garbage after the first JSON object, it will
+silently stop parsing there and return the number of characters consumed
+so far.
+
+This is useful if your JSON texts are not delimited by an outer protocol
+and you need to know where the JSON text ends.
+
+ JSON->new->decode_prefix ("[1] the tail")
+ => ([1], 3)
+
+=head1 ADDITIONAL METHODS
+
+The following methods are for this module only.
+
+=head2 backend
+
+ $backend = $json->backend
+
+Since 2.92, C<backend> method returns an abstract backend module used currently,
+which should be JSON::Backend::XS (which inherits JSON::XS or Cpanel::JSON::XS),
+or JSON::Backend::PP (which inherits JSON::PP), not to monkey-patch the actual
+backend module globally.
+
+If you need to know what is used actually, use C<isa>, instead of string comparison.
+
+=head2 is_xs
+
+ $boolean = $json->is_xs
+
+Returns true if the backend inherits JSON::XS or Cpanel::JSON::XS.
+
+=head2 is_pp
+
+ $boolean = $json->is_pp
+
+Returns true if the backend inherits JSON::PP.
+
+=head2 property
+
+ $settings = $json->property()
+
+Returns a reference to a hash that holds all the common flag settings.
+
+ $json = $json->property('utf8' => 1)
+ $value = $json->property('utf8') # 1
+
+You can use this to get/set a value of a particular flag.
+
+=head1 INCREMENTAL PARSING
+
+This section is also taken from JSON::XS.
+
+In some cases, there is the need for incremental parsing of JSON
+texts. While this module always has to keep both JSON text and resulting
+Perl data structure in memory at one time, it does allow you to parse a
+JSON stream incrementally. It does so by accumulating text until it has
+a full JSON object, which it then can decode. This process is similar to
+using C<decode_prefix> to see if a full JSON object is available, but
+is much more efficient (and can be implemented with a minimum of method
+calls).
+
+This module will only attempt to parse the JSON text once it is sure it
+has enough text to get a decisive result, using a very simple but
+truly incremental parser. This means that it sometimes won't stop as
+early as the full parser, for example, it doesn't detect mismatched
+parentheses. The only thing it guarantees is that it starts decoding as
+soon as a syntactically valid JSON text has been seen. This means you need
+to set resource limits (e.g. C<max_size>) to ensure the parser will stop
+parsing in the presence if syntax errors.
+
+The following methods implement this incremental parser.
+
+=head2 incr_parse
+
+ $json->incr_parse( [$string] ) # void context
+
+ $obj_or_undef = $json->incr_parse( [$string] ) # scalar context
+
+ @obj_or_empty = $json->incr_parse( [$string] ) # list context
+
+This is the central parsing function. It can both append new text and
+extract objects from the stream accumulated so far (both of these
+functions are optional).
+
+If C<$string> is given, then this string is appended to the already
+existing JSON fragment stored in the C<$json> object.
+
+After that, if the function is called in void context, it will simply
+return without doing anything further. This can be used to add more text
+in as many chunks as you want.
+
+If the method is called in scalar context, then it will try to extract
+exactly I<one> JSON object. If that is successful, it will return this
+object, otherwise it will return C<undef>. If there is a parse error,
+this method will croak just as C<decode> would do (one can then use
+C<incr_skip> to skip the erroneous part). This is the most common way of
+using the method.
+
+And finally, in list context, it will try to extract as many objects
+from the stream as it can find and return them, or the empty list
+otherwise. For this to work, there must be no separators (other than
+whitespace) between the JSON objects or arrays, instead they must be
+concatenated back-to-back. If an error occurs, an exception will be
+raised as in the scalar context case. Note that in this case, any
+previously-parsed JSON texts will be lost.
+
+Example: Parse some JSON arrays/objects in a given string and return
+them.
+
+ my @objs = JSON->new->incr_parse ("[5][7][1,2]");
+
+=head2 incr_text
+
+ $lvalue_string = $json->incr_text
+
+This method returns the currently stored JSON fragment as an lvalue, that
+is, you can manipulate it. This I<only> works when a preceding call to
+C<incr_parse> in I<scalar context> successfully returned an object. Under
+all other circumstances you must not call this function (I mean it.
+although in simple tests it might actually work, it I<will> fail under
+real world conditions). As a special exception, you can also call this
+method before having parsed anything.
+
+That means you can only use this function to look at or manipulate text
+before or after complete JSON objects, not while the parser is in the
+middle of parsing a JSON object.
+
+This function is useful in two cases: a) finding the trailing text after a
+JSON object or b) parsing multiple JSON objects separated by non-JSON text
+(such as commas).
+
+=head2 incr_skip
+
+ $json->incr_skip
+
+This will reset the state of the incremental parser and will remove
+the parsed text from the input buffer so far. This is useful after
+C<incr_parse> died, in which case the input buffer and incremental parser
+state is left unchanged, to skip the text parsed so far and to reset the
+parse state.
+
+The difference to C<incr_reset> is that only text until the parse error
+occurred is removed.
+
+=head2 incr_reset
+
+ $json->incr_reset
+
+This completely resets the incremental parser, that is, after this call,
+it will be as if the parser had never parsed anything.
+
+This is useful if you want to repeatedly parse JSON objects and want to
+ignore any trailing data, which means you have to reset the parser after
+each successful decode.
+
+=head1 MAPPING
+
+Most of this section is also taken from JSON::XS.
+
+This section describes how the backend modules map Perl values to JSON values and
+vice versa. These mappings are designed to "do the right thing" in most
+circumstances automatically, preserving round-tripping characteristics
+(what you put in comes out as something equivalent).
+
+For the more enlightened: note that in the following descriptions,
+lowercase I<perl> refers to the Perl interpreter, while uppercase I<Perl>
+refers to the abstract Perl language itself.
+
+=head2 JSON -> PERL
+
+=over 4
+
+=item object
+
+A JSON object becomes a reference to a hash in Perl. No ordering of object
+keys is preserved (JSON does not preserver object key ordering itself).
+
+=item array
+
+A JSON array becomes a reference to an array in Perl.
+
+=item string
+
+A JSON string becomes a string scalar in Perl - Unicode codepoints in JSON
+are represented by the same codepoints in the Perl string, so no manual
+decoding is necessary.
+
+=item number
+
+A JSON number becomes either an integer, numeric (floating point) or
+string scalar in perl, depending on its range and any fractional parts. On
+the Perl level, there is no difference between those as Perl handles all
+the conversion details, but an integer may take slightly less memory and
+might represent more values exactly than floating point numbers.
+
+If the number consists of digits only, this module will try to represent
+it as an integer value. If that fails, it will try to represent it as
+a numeric (floating point) value if that is possible without loss of
+precision. Otherwise it will preserve the number as a string value (in
+which case you lose roundtripping ability, as the JSON number will be
+re-encoded to a JSON string).
+
+Numbers containing a fractional or exponential part will always be
+represented as numeric (floating point) values, possibly at a loss of
+precision (in which case you might lose perfect roundtripping ability, but
+the JSON number will still be re-encoded as a JSON number).
+
+Note that precision is not accuracy - binary floating point values cannot
+represent most decimal fractions exactly, and when converting from and to
+floating point, this module only guarantees precision up to but not including
+the least significant bit.
+
+=item true, false
+
+These JSON atoms become C<JSON::true> and C<JSON::false>,
+respectively. They are overloaded to act almost exactly like the numbers
+C<1> and C<0>. You can check whether a scalar is a JSON boolean by using
+the C<JSON::is_bool> function.
+
+=item null
+
+A JSON null atom becomes C<undef> in Perl.
+
+=item shell-style comments (C<< # I<text> >>)
+
+As a nonstandard extension to the JSON syntax that is enabled by the
+C<relaxed> setting, shell-style comments are allowed. They can start
+anywhere outside strings and go till the end of the line.
+
+=back
+
+
+=head2 PERL -> JSON
+
+The mapping from Perl to JSON is slightly more difficult, as Perl is a
+truly typeless language, so we can only guess which JSON type is meant by
+a Perl value.
+
+=over 4
+
+=item hash references
+
+Perl hash references become JSON objects. As there is no inherent
+ordering in hash keys (or JSON objects), they will usually be encoded
+in a pseudo-random order. This module can optionally sort the hash keys
+(determined by the I<canonical> flag), so the same data structure will
+serialise to the same JSON text (given same settings and version of
+the same backend), but this incurs a runtime overhead and is only rarely useful,
+e.g. when you want to compare some JSON text against another for equality.
+
+=item array references
+
+Perl array references become JSON arrays.
+
+=item other references
+
+Other unblessed references are generally not allowed and will cause an
+exception to be thrown, except for references to the integers C<0> and
+C<1>, which get turned into C<false> and C<true> atoms in JSON. You can
+also use C<JSON::false> and C<JSON::true> to improve readability.
+
+ encode_json [\0,JSON::true] # yields [false,true]
+
+=item JSON::true, JSON::false, JSON::null
+
+These special values become JSON true and JSON false values,
+respectively. You can also use C<\1> and C<\0> directly if you want.
+
+=item blessed objects
+
+Blessed objects are not directly representable in JSON, but C<JSON::XS>
+allows various ways of handling objects. See L<OBJECT SERIALISATION>,
+below, for details.
+
+=item simple scalars
+
+Simple Perl scalars (any scalar that is not a reference) are the most
+difficult objects to encode: this module will encode undefined scalars as
+JSON C<null> values, scalars that have last been used in a string context
+before encoding as JSON strings, and anything else as number value:
+
+ # dump as number
+ encode_json [2] # yields [2]
+ encode_json [-3.0e17] # yields [-3e+17]
+ my $value = 5; encode_json [$value] # yields [5]
+
+ # used as string, so dump as string
+ print $value;
+ encode_json [$value] # yields ["5"]
+
+ # undef becomes null
+ encode_json [undef] # yields [null]
+
+You can force the type to be a string by stringifying it:
+
+ my $x = 3.1; # some variable containing a number
+ "$x"; # stringified
+ $x .= ""; # another, more awkward way to stringify
+ print $x; # perl does it for you, too, quite often
+
+You can force the type to be a number by numifying it:
+
+ my $x = "3"; # some variable containing a string
+ $x += 0; # numify it, ensuring it will be dumped as a number
+ $x *= 1; # same thing, the choice is yours.
+
+You can not currently force the type in other, less obscure, ways. Tell me
+if you need this capability (but don't forget to explain why it's needed
+:).
+
+Note that numerical precision has the same meaning as under Perl (so
+binary to decimal conversion follows the same rules as in Perl, which
+can differ to other languages). Also, your perl interpreter might expose
+extensions to the floating point numbers of your platform, such as
+infinities or NaN's - these cannot be represented in JSON, and it is an
+error to pass those in.
+
+=back
+
+=head2 OBJECT SERIALISATION
+
+As for Perl objects, this module only supports a pure JSON representation
+(without the ability to deserialise the object automatically again).
+
+=head3 SERIALISATION
+
+What happens when this module encounters a Perl object depends on the
+C<allow_blessed> and C<convert_blessed> settings, which are used in
+this order:
+
+=over 4
+
+=item 1. C<convert_blessed> is enabled and the object has a C<TO_JSON> method.
+
+In this case, the C<TO_JSON> method of the object is invoked in scalar
+context. It must return a single scalar that can be directly encoded into
+JSON. This scalar replaces the object in the JSON text.
+
+For example, the following C<TO_JSON> method will convert all L<URI>
+objects to JSON strings when serialised. The fact that these values
+originally were L<URI> objects is lost.
+
+ sub URI::TO_JSON {
+ my ($uri) = @_;
+ $uri->as_string
+ }
+
+=item 2. C<allow_blessed> is enabled.
+
+The object will be serialised as a JSON null value.
+
+=item 3. none of the above
+
+If none of the settings are enabled or the respective methods are missing,
+this module throws an exception.
+
+=back
+
+=head1 ENCODING/CODESET FLAG NOTES
+
+This section is taken from JSON::XS.
+
+The interested reader might have seen a number of flags that signify
+encodings or codesets - C<utf8>, C<latin1> and C<ascii>. There seems to be
+some confusion on what these do, so here is a short comparison:
+
+C<utf8> controls whether the JSON text created by C<encode> (and expected
+by C<decode>) is UTF-8 encoded or not, while C<latin1> and C<ascii> only
+control whether C<encode> escapes character values outside their respective
+codeset range. Neither of these flags conflict with each other, although
+some combinations make less sense than others.
+
+Care has been taken to make all flags symmetrical with respect to
+C<encode> and C<decode>, that is, texts encoded with any combination of
+these flag values will be correctly decoded when the same flags are used
+- in general, if you use different flag settings while encoding vs. when
+decoding you likely have a bug somewhere.
+
+Below comes a verbose discussion of these flags. Note that a "codeset" is
+simply an abstract set of character-codepoint pairs, while an encoding
+takes those codepoint numbers and I<encodes> them, in our case into
+octets. Unicode is (among other things) a codeset, UTF-8 is an encoding,
+and ISO-8859-1 (= latin 1) and ASCII are both codesets I<and> encodings at
+the same time, which can be confusing.
+
+=over 4
+
+=item C<utf8> flag disabled
+
+When C<utf8> is disabled (the default), then C<encode>/C<decode> generate
+and expect Unicode strings, that is, characters with high ordinal Unicode
+values (> 255) will be encoded as such characters, and likewise such
+characters are decoded as-is, no changes to them will be done, except
+"(re-)interpreting" them as Unicode codepoints or Unicode characters,
+respectively (to Perl, these are the same thing in strings unless you do
+funny/weird/dumb stuff).
+
+This is useful when you want to do the encoding yourself (e.g. when you
+want to have UTF-16 encoded JSON texts) or when some other layer does
+the encoding for you (for example, when printing to a terminal using a
+filehandle that transparently encodes to UTF-8 you certainly do NOT want
+to UTF-8 encode your data first and have Perl encode it another time).
+
+=item C<utf8> flag enabled
+
+If the C<utf8>-flag is enabled, C<encode>/C<decode> will encode all
+characters using the corresponding UTF-8 multi-byte sequence, and will
+expect your input strings to be encoded as UTF-8, that is, no "character"
+of the input string must have any value > 255, as UTF-8 does not allow
+that.
+
+The C<utf8> flag therefore switches between two modes: disabled means you
+will get a Unicode string in Perl, enabled means you get an UTF-8 encoded
+octet/binary string in Perl.
+
+=item C<latin1> or C<ascii> flags enabled
+
+With C<latin1> (or C<ascii>) enabled, C<encode> will escape characters
+with ordinal values > 255 (> 127 with C<ascii>) and encode the remaining
+characters as specified by the C<utf8> flag.
+
+If C<utf8> is disabled, then the result is also correctly encoded in those
+character sets (as both are proper subsets of Unicode, meaning that a
+Unicode string with all character values < 256 is the same thing as a
+ISO-8859-1 string, and a Unicode string with all character values < 128 is
+the same thing as an ASCII string in Perl).
+
+If C<utf8> is enabled, you still get a correct UTF-8-encoded string,
+regardless of these flags, just some more characters will be escaped using
+C<\uXXXX> then before.
+
+Note that ISO-8859-1-I<encoded> strings are not compatible with UTF-8
+encoding, while ASCII-encoded strings are. That is because the ISO-8859-1
+encoding is NOT a subset of UTF-8 (despite the ISO-8859-1 I<codeset> being
+a subset of Unicode), while ASCII is.
+
+Surprisingly, C<decode> will ignore these flags and so treat all input
+values as governed by the C<utf8> flag. If it is disabled, this allows you
+to decode ISO-8859-1- and ASCII-encoded strings, as both strict subsets of
+Unicode. If it is enabled, you can correctly decode UTF-8 encoded strings.
+
+So neither C<latin1> nor C<ascii> are incompatible with the C<utf8> flag -
+they only govern when the JSON output engine escapes a character or not.
+
+The main use for C<latin1> is to relatively efficiently store binary data
+as JSON, at the expense of breaking compatibility with most JSON decoders.
+
+The main use for C<ascii> is to force the output to not contain characters
+with values > 127, which means you can interpret the resulting string
+as UTF-8, ISO-8859-1, ASCII, KOI8-R or most about any character set and
+8-bit-encoding, and still get the same data structure back. This is useful
+when your channel for JSON transfer is not 8-bit clean or the encoding
+might be mangled in between (e.g. in mail), and works because ASCII is a
+proper subset of most 8-bit and multibyte encodings in use in the world.
+
+=back
+
+=head1 BACKWARD INCOMPATIBILITY
+
+Since version 2.90, stringification (and string comparison) for
+C<JSON::true> and C<JSON::false> has not been overloaded. It shouldn't
+matter as long as you treat them as boolean values, but a code that
+expects they are stringified as "true" or "false" doesn't work as
+you have expected any more.
+
+ if (JSON::true eq 'true') { # now fails
+
+ print "The result is $JSON::true now."; # => The result is 1 now.
+
+And now these boolean values don't inherit JSON::Boolean, either.
+When you need to test a value is a JSON boolean value or not, use
+C<JSON::is_bool> function, instead of testing the value inherits
+a particular boolean class or not.
+
+=head1 BUGS
+
+Please report bugs on backend selection and additional features
+this module provides to RT or GitHub issues for this module:
+
+=over 4
+
+=item https://rt.cpan.org/Public/Dist/Display.html?Queue=JSON
+
+=item https://github.com/makamaka/JSON/issues
+
+=back
+
+Please report bugs and feature requests on decoding/encoding
+and boolean behaviors to the author of the backend module you
+are using.
+
+=head1 SEE ALSO
+
+L<JSON::XS>, L<Cpanel::JSON::XS>, L<JSON::PP> for backends.
+
+L<JSON::MaybeXS>, an alternative that prefers Cpanel::JSON::XS.
+
+C<RFC4627>(L<http://www.ietf.org/rfc/rfc4627.txt>)
+
+=head1 AUTHOR
+
+Makamaka Hannyaharamitu, E<lt>makamaka[at]cpan.orgE<gt>
+
+JSON::XS was written by Marc Lehmann <schmorp[at]schmorp.de>
+
+The release of this new version owes to the courtesy of Marc Lehmann.
+
+
+=head1 COPYRIGHT AND LICENSE
+
+Copyright 2005-2013 by Makamaka Hannyaharamitu
+
+This library is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself.
+
+=cut
+
Property changes on: trunk/Master/tlpkg/TeXLive/JSON.pm
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
More information about the tex-live-commits
mailing list