trunk/src/third_party/JSON/JSON-2.59/lib/JSON.pm - Issue 16539003: Revert 205057 "Add JSON.pm to third_party"

Unified Diff: trunk/src/third_party/JSON/JSON-2.59/lib/JSON.pm

Issue 16539003: Revert 205057 "Add JSON.pm to third_party" (Closed) Base URL: svn://svn.chromium.org/chrome/

Patch Set: Created 7 years, 6 months ago

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Index: trunk/src/third_party/JSON/JSON-2.59/lib/JSON.pm

===================================================================

--- trunk/src/third_party/JSON/JSON-2.59/lib/JSON.pm (revision 205060)

+++ trunk/src/third_party/JSON/JSON-2.59/lib/JSON.pm (working copy)

@@ -1,2292 +0,0 @@

-package JSON;

-use strict;

-use Carp ();

-use base qw(Exporter);

-@JSON::EXPORT = qw(from_json to_json jsonToObj objToJson encode_json decode_json);

-BEGIN {

- $JSON::VERSION = '2.59';

- $JSON::DEBUG = 0 unless (defined $JSON::DEBUG);

- $JSON::DEBUG = $ENV{ PERL_JSON_DEBUG } if exists $ENV{ PERL_JSON_DEBUG };

-my $Module_XS = 'JSON::XS';

-my $Module_PP = 'JSON::PP';

-my $Module_bp = 'JSON::backportPP'; # included in JSON distribution

-my $PP_Version = '2.27200';

-my $XS_Version = '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//; # 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 $_INSTALL_ONLY = 2; # Don't call _set_methods()

-my $_ALLOW_UNSUPPORTED = 0;

-my $_UNIV_CONV_BLESSED = 0;

-my $_USSING_bpPP = 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' or $backend =~ /JSON::XS\s*,\s*JSON::PP/) {

- _load_xs($_INSTALL_DONT_DIE) or _load_pp();

- }

- elsif ($backend eq '0' or $backend eq 'JSON::PP') {

- _load_pp();

- }

- elsif ($backend eq '2' or $backend eq 'JSON::XS') {

- _load_xs();

- }

- elsif ($backend eq 'JSON::backportPP') {

- $_USSING_bpPP = 1;

- _load_pp();

- }

- else {

- Carp::croak "The value of environmental variable 'PERL_JSON_BACKEND' is invalid.";

- }

-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 eq $Module_XS);

- }

- next;

- }

- elsif ($tag eq '-no_export') {

- $no_export++, next;

- }

- elsif ( $tag eq '-convert_blessed_universally' ) {

- eval q|

- require B;

- *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

- ;

- }

- | 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 { $XS_Version; }

-sub backend {

- my $proto = shift;

- $JSON::Backend;

-#*module = *backend;

-sub is_xs {

- return $_[0]->module eq $Module_XS;

-sub is_pp {

- return not $_[0]->xs;

-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 $opt = shift;

- $JSON::DEBUG and Carp::carp "Load $Module_XS.";

- # if called after install module, overload is disable.... why?

- JSON::Boolean::_overrride_overload($Module_XS);

- JSON::Boolean::_overrride_overload($Module_PP);

- eval qq|

- use $Module_XS $XS_Version ();

- |;

- if ($@) {

- if (defined $opt and $opt & $_INSTALL_DONT_DIE) {

- $JSON::DEBUG and Carp::carp "Can't load $Module_XS...($@)";

- return 0;

- }

- Carp::croak $@;

- }

- unless (defined $opt and $opt & $_INSTALL_ONLY) {

- _set_module( $JSON::Backend = $Module_XS );

- my $data = join("", <DATA>); # this code is from Jcode 2.xx.

- close(DATA);

- eval $data;

- JSON::Backend::XS->init;

- }

- return 1;

-};

-sub _load_pp {

- my $opt = shift;

- my $backend = $_USSING_bpPP ? $Module_bp : $Module_PP;

- $JSON::DEBUG and Carp::carp "Load $backend.";

- # if called after install module, overload is disable.... why?

- JSON::Boolean::_overrride_overload($Module_XS);

- JSON::Boolean::_overrride_overload($backend);

- if ( $_USSING_bpPP ) {

- eval qq| require $backend |;

- }

- else {

- eval qq| use $backend $PP_Version () |;

- }

- if ($@) {

- if ( $backend eq $Module_PP ) {

- $JSON::DEBUG and Carp::carp "Can't load $Module_PP ($@), so try to load $Module_bp";

- $_USSING_bpPP++;

- $backend = $Module_bp;

- JSON::Boolean::_overrride_overload($backend);

- local $^W; # if PP installed but invalid version, backportPP redefines methods.

- eval qq| require $Module_bp |;

- }

- Carp::croak $@ if $@;

- }

- unless (defined $opt and $opt & $_INSTALL_ONLY) {

- _set_module( $JSON::Backend = $Module_PP ); # even if backportPP, set $Backend with 'JSON::PP'

- JSON::Backend::PP->init;

- }

-};

-sub _set_module {

- return if defined $JSON::true;

- my $module = shift;

- local $^W;

- no strict qw(refs);

- $JSON::true = ${"$module\::true"};

- $JSON::false = ${"$module\::false"};

- push @JSON::ISA, $module;

- push @{"$module\::Boolean::ISA"}, qw(JSON::Boolean);

- *{"JSON::is_bool"} = \&{"$module\::is_bool"};

- for my $method ($module eq $Module_XS ? @PPOnlyMethods : @XSOnlyMethods) {

- *{"JSON::$method"} = sub {

- Carp::carp("$method is not supported in $module.");

- $_[0];

- };

- }

- return 1;

-# JSON Boolean

-package JSON::Boolean;

-my %Installed;

-sub _overrride_overload {

- return if ($Installed{ $_[0] }++);

- my $boolean = $_[0] . '::Boolean';

- eval sprintf(q|

- package %s;

- use overload (

- '""' => sub { ${$_[0]} == 1 ? 'true' : 'false' },

- 'eq' => sub {

- my ($obj, $op) = ref ($_[0]) ? ($_[0], $_[1]) : ($_[1], $_[0]);

- if ($op eq 'true' or $op eq 'false') {

- return "$obj" eq 'true' ? 'true' eq $op : 'false' eq $op;

- }

- else {

- return $obj ? 1 == $op : 0 == $op;

- }

- },

- );

- |, $boolean);

- if ($@) { Carp::croak $@; }

- if ( exists $INC{'JSON/XS.pm'} and $boolean eq 'JSON::XS::Boolean' ) {

- local $^W;

- my $true = do { bless \(my $dummy = 1), $boolean };

- my $false = do { bless \(my $dummy = 0), $boolean };

- *JSON::XS::true = sub () { $true };

- *JSON::XS::false = sub () { $false };

- }

- elsif ( exists $INC{'JSON/PP.pm'} and $boolean eq 'JSON::PP::Boolean' ) {

- local $^W;

- my $true = do { bless \(my $dummy = 1), $boolean };

- my $false = do { bless \(my $dummy = 0), $boolean };

- *JSON::PP::true = sub { $true };

- *JSON::PP::false = sub { $false };

- }

- return 1;

-# Helper classes for Backend Module (PP)

-package JSON::Backend::PP;

-sub init {

- 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::PP::is_xs"} = sub { 0 };

- *{"JSON::PP::is_pp"} = sub { 1 };

- return 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;

-use constant INDENT_LENGTH_FLAG => 15 << 12;

-use constant UNSUPPORTED_ENCODE_FLAG => {

- ESCAPE_SLASH => 0x00000010,

- ALLOW_BIGNUM => 0x00000020,

- AS_NONBLESSED => 0x00000040,

- EXPANDED => 0x10000000, # for developer's

-};

-use constant UNSUPPORTED_DECODE_FLAG => {

- LOOSE => 0x00000001,

- ALLOW_BIGNUM => 0x00000002,

- ALLOW_BAREKEY => 0x00000004,

- ALLOW_SINGLEQUOTE => 0x00000008,

- EXPANDED => 0x20000000, # for developer's

-};

-sub init {

- local $^W;

- no strict qw(refs);

- *{"JSON::decode_json"} = \&{"JSON::XS::decode_json"};

- *{"JSON::encode_json"} = \&{"JSON::XS::encode_json"};

- *{"JSON::XS::is_xs"} = sub { 1 };

- *{"JSON::XS::is_pp"} = sub { 0 };

- return 1;

-sub support_by_pp {

- my ($class, @methods) = @_;

- local $^W;

- no strict qw(refs);

- my $JSON_XS_encode_orignal = \&JSON::XS::encode;

- my $JSON_XS_decode_orignal = \&JSON::XS::decode;

- my $JSON_XS_incr_parse_orignal = \&JSON::XS::incr_parse;

- *JSON::XS::decode = \&JSON::Backend::XS::Supportable::_decode;

- *JSON::XS::encode = \&JSON::Backend::XS::Supportable::_encode;

- *JSON::XS::incr_parse = \&JSON::Backend::XS::Supportable::_incr_parse;

- *{JSON::XS::_original_decode} = $JSON_XS_decode_orignal;

- *{JSON::XS::_original_encode} = $JSON_XS_encode_orignal;

- *{JSON::XS::_original_incr_parse} = $JSON_XS_incr_parse_orignal;

- push @JSON::Backend::XS::Supportable::ISA, 'JSON';

- my $pkg = 'JSON::Backend::XS::Supportable';

- *{JSON::new} = sub {

- my $proto = JSON::XS->new; $$proto = 0;

- bless $proto, $pkg;

- };

- for my $method (@methods) {

- my $flag = uc($method);

- my $type |= (UNSUPPORTED_ENCODE_FLAG->{$flag} || 0);

- $type |= (UNSUPPORTED_DECODE_FLAG->{$flag} || 0);

- next unless($type);

- $pkg->_make_unsupported_method($method => $type);

- }

- push @{"JSON::XS::Boolean::ISA"}, qw(JSON::PP::Boolean);

- push @{"JSON::PP::Boolean::ISA"}, qw(JSON::Boolean);

- $JSON::DEBUG and Carp::carp("set -support_by_pp mode.");

- return 1;

-# Helper classes for XS

-package JSON::Backend::XS::Supportable;

-$Carp::Internal{'JSON::Backend::XS::Supportable'} = 1;

-sub _make_unsupported_method {

- my ($pkg, $method, $type) = @_;

- local $^W;

- no strict qw(refs);

- *{"$pkg\::$method"} = sub {

- local $^W;

- if (defined $_[1] ? $_[1] : 1) {

- ${$_[0]} |= $type;

- }

- else {

- ${$_[0]} &= ~$type;

- }

- $_[0];

- };

- *{"$pkg\::get_$method"} = sub {

- ${$_[0]} & $type ? 1 : '';

- };

-sub _set_for_pp {

- JSON::_load_pp( $_INSTALL_ONLY );

- my $type = shift;

- my $pp = JSON::PP->new;

- my $prop = $_[0]->property;

- for my $name (keys %$prop) {

- $pp->$name( $prop->{$name} ? $prop->{$name} : 0 );

- }

- my $unsupported = $type eq 'encode' ? JSON::Backend::XS::UNSUPPORTED_ENCODE_FLAG

- : JSON::Backend::XS::UNSUPPORTED_DECODE_FLAG;

- my $flags = ${$_[0]} || 0;

- for my $name (keys %$unsupported) {

- next if ($name eq 'EXPANDED'); # for developer's

- my $enable = ($flags & $unsupported->{$name}) ? 1 : 0;

- my $method = lc $name;

- $pp->$method($enable);

- }

- $pp->indent_length( $_[0]->get_indent_length );

- return $pp;

-sub _encode { # using with PP encode

- if (${$_[0]}) {

- _set_for_pp('encode' => @_)->encode($_[1]);

- }

- else {

- $_[0]->_original_encode( $_[1] );

- }

-sub _decode { # if unsupported-flag is set, use PP

- if (${$_[0]}) {

- _set_for_pp('decode' => @_)->decode($_[1]);

- }

- else {

- $_[0]->_original_decode( $_[1] );

- }

-sub decode_prefix { # if unsupported-flag is set, use PP

- _set_for_pp('decode' => @_)->decode_prefix($_[1]);

-sub _incr_parse {

- if (${$_[0]}) {

- _set_for_pp('decode' => @_)->incr_parse($_[1]);

- }

- else {

- $_[0]->_original_incr_parse( $_[1] );

- }

-sub get_indent_length {

- ${$_[0]} << 4 >> 16;

-sub indent_length {

- my $length = $_[1];

- if (!defined $length or $length > 15 or $length < 0) {

- Carp::carp "The acceptable range of indent_length() is 0 to 15.";

- }

- else {

- local $^W;

- $length <<= 12;

- ${$_[0]} &= ~ JSON::Backend::XS::INDENT_LENGTH_FLAG;

- ${$_[0]} |= $length;

- *JSON::XS::encode = \&JSON::Backend::XS::Supportable::_encode;

- }

- $_[0];

-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

- # If you want to use PP only support features, call with '-support_by_pp'

- # When XS unsupported feature is enable, using PP (de|en)code instead of XS ones.

- use JSON -support_by_pp;

- # option-acceptable interfaces (expect/generate UNICODE by default)

- $json_text = to_json( $perl_scalar, { ascii => 1, pretty => 1 } );

- $perl_scalar = from_json( $json_text, { utf8 => 1 } );

- # Between (en|de)code_json and (to|from)_json, if you want to write

- # a code which communicates to an outer world (encoded in UTF-8),

- # recommend to use (en|de)code_json.

-=head1 VERSION

- 2.59

-This version is compatible with JSON::XS B<2.34> and later.

-=head1 NOTE

-JSON::PP was earlier included in the C<JSON> distribution, but

-has since Perl 5.14 been a core module. For this reason,

-L<JSON::PP> was removed from the JSON distribution and can now

-be found also in the Perl5 repository at

-=over

-=item * L<http://perl5.git.perl.org/perl.git>

-=back

-(The newest JSON::PP version still exists in CPAN.)

-Instead, the C<JSON> distribution will include JSON::backportPP

-for backwards computability. JSON.pm should thus work as it did

-before.

-=head1 DESCRIPTION

- ************************** CAUTION ********************************

- * This is 'JSON module version 2' and there are many differences *

- * to version 1.xx *

- * Please check your applications using old version. *

- * See to 'INCOMPATIBLE CHANGES TO OLD VERSION' *

- *******************************************************************

-JSON (JavaScript Object Notation) is a simple data format.

-See to L<http://www.json.org/> and C<RFC4627>(L<http://www.ietf.org/rfc/rfc4627.txt>).

-This module converts Perl data structures to JSON and vice versa using either

-L<JSON::XS> or L<JSON::PP>.

-JSON::XS is the fastest and most proper JSON module on CPAN which must be

-compiled and installed in your environment.

-JSON::PP is a pure-Perl module which is bundled in this distribution and

-has a strong compatibility to JSON::XS.

-This module try to use JSON::XS by default and fail to it, use JSON::PP instead.

-So its features completely depend on JSON::XS or JSON::PP.

-See to L<BACKEND MODULE DECISION>.

-To distinguish the module name 'JSON' and the format type JSON,

-the former is quoted by CE<lt>E<gt> (its results vary with your using media),

-and the latter is left just as it is.

-Module name : C<JSON>

-Format type : JSON

-=head2 FEATURES

-=over

-=item * correct unicode handling

-This module (i.e. backend modules) knows how to handle Unicode, documents

-how and when it does so, and even documents what "correct" means.

-Even though there are limitations, this feature is available since Perl version 5.6.

-JSON::XS requires Perl 5.8.2 (but works correctly in 5.8.8 or later), so in older versions

-C<JSON> should call JSON::PP as the backend which can be used since Perl 5.005.

-With Perl 5.8.x JSON::PP works, but from 5.8.0 to 5.8.2, because of a Perl side problem,

-JSON::PP works slower in the versions. And in 5.005, the Unicode handling is not available.

-See to L<JSON::PP/UNICODE HANDLING ON PERLS> for more information.

-See also to L<JSON::XS/A FEW NOTES ON UNICODE AND PERL>

-and L<JSON::XS/ENCODING/CODESET_FLAG_NOTES>.

-=item * round-trip integrity

-When you serialise a perl data structure using only data types supported

-by JSON and Perl, the deserialised data structure is identical on the Perl

-level. (e.g. the string "2.0" doesn't suddenly become "2" just because

-it looks like a number). There I<are> minor exceptions to this, read the

-L</MAPPING> section below to learn about those.

-=item * strict checking of JSON correctness

-There is no guessing, no generating of illegal JSON texts by default,

-and only JSON is accepted as input by default (the latter is a security

-feature).

-See to L<JSON::XS/FEATURES> and L<JSON::PP/FEATURES>.

-=item * fast

-This module returns a JSON::XS object itself if available.

-Compared to other JSON modules and other serialisers such as Storable,

-JSON::XS usually compares favorably in terms of speed, too.

-If not available, C<JSON> returns a JSON::PP object instead of JSON::XS and

-it is very slow as pure-Perl.

-=item * simple to use

-This module has both a simple functional interface as well as an

-object oriented interface interface.

-=item * reasonably versatile output formats

-You can choose between the most compact guaranteed-single-line format possible

-(nice for simple line-based protocols), a pure-ASCII format (for when your transport

-is not 8-bit clean, still supports the whole Unicode range), or a pretty-printed

-format (for when you want to read that stuff). Or you can combine those features

-in whatever way you like.

-=back

-=head1 FUNCTIONAL INTERFACE

-Some documents are copied and modified from L<JSON::XS/FUNCTIONAL INTERFACE>.

-C<to_json> and C<from_json> are additional functions.

-=head2 encode_json

- $json_text = encode_json $perl_scalar

-Converts the given Perl data structure to a UTF-8 encoded, binary string.

-This function call is functionally identical to:

- $json_text = JSON->new->utf8->encode($perl_scalar)

-=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.

-This function call is functionally identical to:

- $perl_scalar = JSON->new->utf8->decode($json_text)

-=head2 to_json

- $json_text = to_json($perl_scalar)

-Converts the given Perl data structure to a json string.

-This function call is functionally identical to:

- $json_text = JSON->new->encode($perl_scalar)

-Takes a hash reference as the second.

- $json_text = to_json($perl_scalar, $flag_hashref)

-So,

- $json_text = to_json($perl_scalar, {utf8 => 1, pretty => 1})

-equivalent to:

- $json_text = JSON->new->utf8(1)->pretty(1)->encode($perl_scalar)

-If you want to write a modern perl code which communicates to outer world,

-you should use C<encode_json> (supposed that JSON data are encoded in UTF-8).

-=head2 from_json

- $perl_scalar = from_json($json_text)

-The opposite of C<to_json>: expects a json string and tries

-to parse it, returning the resulting reference.

-This function call is functionally identical to:

- $perl_scalar = JSON->decode($json_text)

-Takes a hash reference as the second.

- $perl_scalar = from_json($json_text, $flag_hashref)

-So,

- $perl_scalar = from_json($json_text, {utf8 => 1})

-equivalent to:

- $perl_scalar = JSON->new->utf8(1)->decode($json_text)

-If you want to write a modern perl code which communicates to outer world,

-you should use C<decode_json> (supposed that JSON data are encoded in UTF-8).

-=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.

-=head2 JSON::true

-Returns JSON true value which is blessed object.

-It C<isa> JSON::Boolean object.

-=head2 JSON::false

-Returns JSON false value which is blessed object.

-It C<isa> JSON::Boolean object.

-=head2 JSON::null

-Returns C<undef>.

-See L<MAPPING>, below, for more information on how JSON values are mapped to

-Perl.

-=head1 HOW DO I DECODE A DATA FROM OUTER AND ENCODE TO OUTER

-This section supposes that your perl version is 5.8 or later.

-If you know a JSON text from an outer world - a network, a file content, and so on,

-is encoded in UTF-8, you should use C<decode_json> or C<JSON> module object

-with C<utf8> enable. And the decoded result will contain UNICODE characters.

- # from network

- my $json = JSON->new->utf8;

- my $json_text = CGI->new->param( 'json_data' );

- my $perl_scalar = $json->decode( $json_text );

- # from file content

- local $/;

- open( my $fh, '<', 'json.data' );

- $json_text = <$fh>;

- $perl_scalar = decode_json( $json_text );

-If an outer data is not encoded in UTF-8, firstly you should C<decode> it.

- use Encode;

- local $/;

- open( my $fh, '<', 'json.data' );

- my $encoding = 'cp932';

- my $unicode_json_text = decode( $encoding, <$fh> ); # UNICODE

- # or you can write the below code.

- #

- # open( my $fh, "<:encoding($encoding)", 'json.data' );

- # $unicode_json_text = <$fh>;

-In this case, C<$unicode_json_text> is of course UNICODE string.

-So you B<cannot> use C<decode_json> nor C<JSON> module object with C<utf8> enable.

-Instead of them, you use C<JSON> module object with C<utf8> disable or C<from_json>.

- $perl_scalar = $json->utf8(0)->decode( $unicode_json_text );

- # or

- $perl_scalar = from_json( $unicode_json_text );

-Or C<encode 'utf8'> and C<decode_json>:

- $perl_scalar = decode_json( encode( 'utf8', $unicode_json_text ) );

- # this way is not efficient.

-And now, you want to convert your C<$perl_scalar> into JSON data and

-send it to an outer world - a network or a file content, and so on.

-Your data usually contains UNICODE strings and you want the converted data to be encoded

-in UTF-8, you should use C<encode_json> or C<JSON> module object with C<utf8> enable.

- print encode_json( $perl_scalar ); # to a network? file? or display?

- # or

- print $json->utf8->encode( $perl_scalar );

-If C<$perl_scalar> does not contain UNICODE but C<$encoding>-encoded strings

-for some reason, then its characters are regarded as B<latin1> for perl

-(because it does not concern with your $encoding).

-You B<cannot> use C<encode_json> nor C<JSON> module object with C<utf8> enable.

-Instead of them, you use C<JSON> module object with C<utf8> disable or C<to_json>.

-Note that the resulted text is a UNICODE string but no problem to print it.

- # $perl_scalar contains $encoding encoded string values

- $unicode_json_text = $json->utf8(0)->encode( $perl_scalar );

- # or

- $unicode_json_text = to_json( $perl_scalar );

- # $unicode_json_text consists of characters less than 0x100

- print $unicode_json_text;

-Or C<decode $encoding> all string values and C<encode_json>:

- $perl_scalar->{ foo } = decode( $encoding, $perl_scalar->{ foo } );

- # ... do it to each string values, then encode_json

- $json_text = encode_json( $perl_scalar );

-This method is a proper way but probably not efficient.

-See to L<Encode>, L<perluniintro>.

-=head1 COMMON OBJECT-ORIENTED INTERFACE

-=head2 new

- $json = JSON->new

-Returns a new C<JSON> object inherited from either JSON::XS or JSON::PP

-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 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 $enable is true (or missing), then the encode method will not generate characters outside

-the code range 0..127. Any Unicode characters outside that range will be escaped using either

-a single \uXXXX or a double \uHHHH\uLLLLL escape sequence, as per RFC4627.

-If $enable is false, then the 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.

-This feature depends on the used Perl version and environment.

-See to L<JSON::PP/UNICODE HANDLING ON PERLS> if the backend is PP.

- JSON->new->ascii(1)->encode([chr 0x10401])

- => ["\ud801\udc01"]

-=head2 latin1

- $json = $json->latin1([$enable])

- $enabled = $json->get_latin1

-If $enable is true (or missing), then the encode method will encode the resulting JSON

-text as latin1 (or iso-8859-1), escaping any characters outside the code range 0..255.

-If $enable is false, then the encode method will not escape Unicode characters

-unless required by the JSON syntax or other flags.

- 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 $enable is true (or missing), then the encode method will encode the JSON result

-into UTF-8, as required by many protocols, while the 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 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 $enable is false, then the encode method will return the JSON string as a (non-encoded)

-Unicode string, while 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.

-Example, output UTF-16BE-encoded JSON:

- use Encode;

- $jsontext = encode "UTF-16BE", JSON::XS->new->encode ($object);

-Example, decode UTF-32LE-encoded JSON:

- use Encode;

- $object = JSON::XS->new->decode (decode "UTF-32LE", $jsontext);

-See to L<JSON::PP/UNICODE HANDLING ON PERLS> if the backend is PP.

-=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.

-Equivalent to:

- $json->indent->space_before->space_after

-The indent space length is three and JSON::XS cannot change the indent

-space length.

-=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, identifying 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 indent space length is three.

-With JSON::PP, you can also access C<indent_length> to change indent space 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.

-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).

-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.

-=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.

- JSON->new->allow_nonref->encode ("Hello, World!")

- => "Hello, World!"

-=head2 allow_unknown

- $json = $json->allow_unknown ([$enable])

- $enabled = $json->get_allow_unknown

-If $enable is true (or missing), then "encode" will *not* throw an

-exception when it encounters values it cannot represent in JSON (for

-example, filehandles) but instead will encode a JSON "null" value.

-Note that blessed objects are not included here and are handled

-separately by c<allow_nonref>.

-If $enable is false (the default), then "encode" will throw an

-exception when it encounters anything it cannot encode as JSON.

-This option does not affect "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

-If C<$enable> is true (or missing), then the C<encode> method will not

-barf when it encounters a blessed reference. Instead, the value of the

-B<convert_blessed> option will decide whether C<null> (C<convert_blessed>

-disabled or no C<TO_JSON> method found) or a representation of the

-object (C<convert_blessed> enabled and C<TO_JSON> method found) is being

-encoded. Has no effect on C<decode>.

-If C<$enable> is false (the default), then C<encode> will throw an

-exception when it encounters a blessed object.

-=head2 convert_blessed

- $json = $json->convert_blessed([$enable])

- $enabled = $json->get_convert_blessed

-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. If no

-C<TO_JSON> method is found, the value of C<allow_blessed> will decide what

-to do.

-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 the C<to_json>

-function or method.

-This setting does not yet influence C<decode> in any way.

-If C<$enable> is false, then the C<allow_blessed> setting will decide what

-to do when a blessed object is found.

-=over

-=item convert_blessed_universally mode

-If use C<JSON> with C<-convert_blessed_universally>, the C<UNIVERSAL::TO_JSON>

-subroutine is defined as the below code:

- *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

- ;

- }

-This will cause that C<encode> method converts simple blessed objects into

-JSON objects as non-blessed object.

- JSON -convert_blessed_universally;

- $json->allow_blessed->convert_blessed->encode( $blessed_object )

-This feature is experimental and may be removed in the future.

-=back

-=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 passed to the coderef

-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 shrink

- $json = $json->shrink([$enable])

- $enabled = $json->get_shrink

-With JSON::XS, this flag resizes strings generated by either

-C<encode> or C<decode> to their minimum size possible. This can save

-memory when your JSON texts are either very very long or you have many

-short strings. It will also try to downgrade any strings to octet-form

-if possible: perl stores strings internally either in an encoding called

-UTF-X or in octet-form. The latter cannot store everything but uses less

-space in general (and some buggy Perl or C code might even rely on that

-internal representation being used).

-With JSON::PP, it is noop about resizing strings but tries

-C<utf8::downgrade> to the returned string by C<encode>. See to L<utf8>.

-See to L<JSON::XS/OBJECT-ORIENTED INTERFACE> and L<JSON::PP/METHODS>.

-=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.

-If no argument is given, the highest possible setting will be used, which

-is rarely useful.

-Note that nesting is implemented by recursion in C. The default value has

-been chosen to be as large as typical operating systems allow without

-crashing. (JSON::XS)

-With JSON::PP as the backend, when a large value (100 or more) was set and

-it de/encodes a deep nested object/text, it may raise a warning

-'Deep recursion on subroutine' at the perl runtime phase.

-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>, below, for more info on why this is useful.

-=head2 encode

- $json_text = $json->encode($perl_scalar)

-Converts the given Perl data structure (a simple scalar or a reference

-to a hash or array) to its JSON representation. Simple scalars will be

-converted into JSON string or number sequences, while references to arrays

-become JSON arrays and references to hashes become JSON objects. Undefined

-Perl values (e.g. C<undef>) become JSON C<null> values.

-References to the integers C<0> and C<1> are converted into C<true> and C<false>.

-=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.

-JSON numbers and strings become simple Perl scalars. JSON arrays become

-Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes

-C<1> (C<JSON::true>), C<false> becomes C<0> (C<JSON::false>) and

-C<null> becomes C<undef>.

-=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.

- JSON->new->decode_prefix ("[1] the tail")

- => ([], 3)

-See to L<JSON::XS/OBJECT-ORIENTED INTERFACE>

-=head2 property

- $boolean = $json->property($property_name)

-Returns a boolean value about above some properties.

-The available properties are C<ascii>, C<latin1>, C<utf8>,

-C<indent>,C<space_before>, C<space_after>, C<relaxed>, C<canonical>,

-C<allow_nonref>, C<allow_unknown>, C<allow_blessed>, C<convert_blessed>,

-C<shrink>, C<max_depth> and C<max_size>.

- $boolean = $json->property('utf8');

- => 0

- $json->utf8;

- $boolean = $json->property('utf8');

- => 1

-Sets the property with a given boolean value.

- $json = $json->property($property_name => $boolean);

-With no argument, it returns all the above properties as a hash reference.

- $flag_hashref = $json->property();

-=head1 INCREMENTAL PARSING

-Most of this section are copied and modified from L<JSON::XS/INCREMENTAL PARSING>.

-In some cases, there is the need for incremental parsing of JSON texts.

-This module 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).

-The backend 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 parenthesis

-mismatches. 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 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.

-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).

- $json->incr_text =~ s/\s*,\s*//;

-In Perl 5.005, C<lvalue> attribute is not available.

-You must write codes like the below:

- $string = $json->incr_text;

- $string =~ s/\s*,\s*//;

- $json->incr_text( $string );

-=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. 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.

-=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.

-See to L<JSON::XS/INCREMENTAL PARSING> for examples.

-=head1 JSON::PP SUPPORT METHODS

-The below methods are JSON::PP own methods, so when C<JSON> works

-with JSON::PP (i.e. the created object is a JSON::PP object), available.

-See to L<JSON::PP/JSON::PP OWN METHODS> in detail.

-If you use C<JSON> with additional C<-support_by_pp>, some methods

-are available even with JSON::XS. See to L<USE PP FEATURES EVEN THOUGH XS BACKEND>.

- BEING { $ENV{PERL_JSON_BACKEND} = 'JSON::XS' }

- use JSON -support_by_pp;

- my $json = JSON->new;

- $json->allow_nonref->escape_slash->encode("/");

- # functional interfaces too.

- print to_json(["/"], {escape_slash => 1});

- print from_json('["foo"]', {utf8 => 1});

-If you do not want to all functions but C<-support_by_pp>,

-use C<-no_export>.

- use JSON -support_by_pp, -no_export;

- # functional interfaces are not exported.

-=head2 allow_singlequote

- $json = $json->allow_singlequote([$enable])

-If C<$enable> is true (or missing), then C<decode> will accept

-any JSON strings quoted by single quotations that are invalid JSON

-format.

- $json->allow_singlequote->decode({"foo":'bar'});

- $json->allow_singlequote->decode({'foo':"bar"});

- $json->allow_singlequote->decode({'foo':'bar'});

-As same as the C<relaxed> option, this option may be used to parse

-application-specific files written by humans.

-=head2 allow_barekey

- $json = $json->allow_barekey([$enable])

-If C<$enable> is true (or missing), then C<decode> will accept

-bare keys of JSON object that are invalid JSON format.

-As same as the C<relaxed> option, this option may be used to parse

-application-specific files written by humans.

- $json->allow_barekey->decode('{foo:"bar"}');

-=head2 allow_bignum

- $json = $json->allow_bignum([$enable])

-If C<$enable> is true (or missing), then C<decode> will convert

-the big integer Perl cannot handle as integer into a L<Math::BigInt>

-object and convert a floating number (any) into a L<Math::BigFloat>.

-On the contrary, C<encode> converts C<Math::BigInt> objects and C<Math::BigFloat>

-objects into JSON numbers with C<allow_blessed> enable.

- $json->allow_nonref->allow_blessed->allow_bignum;

- $bigfloat = $json->decode('2.000000000000000000000000001');

- print $json->encode($bigfloat);

- # => 2.000000000000000000000000001

-See to L<MAPPING> about the conversion of JSON number.

-=head2 loose

- $json = $json->loose([$enable])

-The unescaped [\x00-\x1f\x22\x2f\x5c] strings are invalid in JSON strings

-and the module doesn't allow to C<decode> to these (except for \x2f).

-If C<$enable> is true (or missing), then C<decode> will accept these

-unescaped strings.

- $json->loose->decode(qq|["abc

- def"]|);

-See to L<JSON::PP/JSON::PP OWN METHODS>.

-=head2 escape_slash

- $json = $json->escape_slash([$enable])

-According to JSON Grammar, I<slash> (U+002F) is escaped. But by default

-JSON backend modules encode strings without escaping slash.

-If C<$enable> is true (or missing), then C<encode> will escape slashes.

-=head2 indent_length

- $json = $json->indent_length($length)

-With JSON::XS, The indent space length is 3 and cannot be changed.

-With JSON::PP, it sets the indent space length with the given $length.

-The default is 3. The acceptable range is 0 to 15.

-=head2 sort_by

- $json = $json->sort_by($function_name)

- $json = $json->sort_by($subroutine_ref)

-If $function_name or $subroutine_ref are set, its sort routine are used.

- $js = $pc->sort_by(sub { $JSON::PP::a cmp $JSON::PP::b })->encode($obj);

- # is($js, q|{"a":1,"b":2,"c":3,"d":4,"e":5,"f":6,"g":7,"h":8,"i":9}|);

- $js = $pc->sort_by('own_sort')->encode($obj);

- # is($js, q|{"a":1,"b":2,"c":3,"d":4,"e":5,"f":6,"g":7,"h":8,"i":9}|);

- sub JSON::PP::own_sort { $JSON::PP::a cmp $JSON::PP::b }

-As the sorting routine runs in the JSON::PP scope, the given

-subroutine name and the special variables C<$a>, C<$b> will begin

-with 'JSON::PP::'.

-If $integer is set, then the effect is same as C<canonical> on.

-See to L<JSON::PP/JSON::PP OWN METHODS>.

-=head1 MAPPING

-This section is copied from JSON::XS and modified to C<JSON>.

-JSON::XS and JSON::PP mapping mechanisms are almost equivalent.

-See to L<JSON::XS/MAPPING>.

-=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, C<JSON> 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, C<JSON> only guarantees precision up to but not including

-the least significant bit.

-If the backend is JSON::PP and C<allow_bignum> is enable, the big integers

-and the numeric can be optionally converted into L<Math::BigInt> and

-L<Math::BigFloat> objects.

-=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.

-If C<JSON::true> and C<JSON::false> are used as strings or compared as strings,

-they represent as C<true> and C<false> respectively.

- print JSON::true . "\n";

- => true

- print JSON::true + 1;

- => 1

- ok(JSON::true eq 'true');

- ok(JSON::true eq '1');

- ok(JSON::true == 1);

-C<JSON> will install these missing overloading features to the backend modules.

-=item null

-A JSON null atom becomes C<undef> in Perl.

-C<JSON::null> returns C<undef>.

-=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 that can change between runs of the same program but

-stays generally the same within a single run of a program. C<JSON>

-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 JSON::XS), 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.

-In future, the ordered object feature will be added to JSON::PP using C<tie> mechanism.

-=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.

- to_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.

-JSON::null returns C<undef>.

-=item blessed objects

-Blessed objects are not directly representable in JSON. See the

-C<allow_blessed> and C<convert_blessed> methods on various options on

-how to deal with this: basically, you can choose between throwing an

-exception, encoding the reference as if it weren't blessed, or provide

-your own serialiser method.

-With C<convert_blessed_universally> mode, C<encode> converts blessed

-hash references or blessed array references (contains other blessed references)

-into JSON members and arrays.

- use JSON -convert_blessed_universally;

- JSON->new->allow_blessed->convert_blessed->encode( $blessed_object );

-See to L<convert_blessed>.

-=item simple scalars

-Simple Perl scalars (any scalar that is not a reference) are the most

-difficult objects to encode: JSON::XS and 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

-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.

-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.

-=item Big Number

-If the backend is JSON::PP and C<allow_bignum> is enable,

-C<encode> converts C<Math::BigInt> objects and C<Math::BigFloat>

-objects into JSON numbers.

-=back

-=head1 JSON and ECMAscript

-See to L<JSON::XS/JSON and ECMAscript>.

-=head1 JSON and YAML

-JSON is not a subset of YAML.

-See to L<JSON::XS/JSON and YAML>.

-=head1 BACKEND MODULE DECISION

-When you use C<JSON>, C<JSON> tries to C<use> JSON::XS. If this call failed, it will

-C<uses> JSON::PP. The required JSON::XS version is I<2.2> or later.

-The C<JSON> constructor method returns an object inherited from the backend module,

-and JSON::XS object is a blessed scalar reference while JSON::PP is a blessed hash

-reference.

-So, your program should not depend on the backend module, especially

-returned objects should not be modified.

- my $json = JSON->new; # XS or PP?

- $json->{stash} = 'this is xs object'; # this code may raise an error!

-To check the backend module, there are some methods - C<backend>, C<is_pp> and C<is_xs>.

- JSON->backend; # 'JSON::XS' or 'JSON::PP'

- JSON->backend->is_pp: # 0 or 1

- JSON->backend->is_xs: # 1 or 0

- $json->is_xs; # 1 or 0

- $json->is_pp; # 0 or 1

-If you set an environment variable C<PERL_JSON_BACKEND>, the calling action will be changed.

-=over

-=item PERL_JSON_BACKEND = 0 or PERL_JSON_BACKEND = 'JSON::PP'

-Always use JSON::PP

-=item PERL_JSON_BACKEND == 1 or PERL_JSON_BACKEND = 'JSON::XS,JSON::PP'

-(The default) Use compiled JSON::XS if it is properly compiled & installed,

-otherwise use JSON::PP.

-=item PERL_JSON_BACKEND == 2 or PERL_JSON_BACKEND = 'JSON::XS'

-Always use compiled JSON::XS, die if it isn't properly compiled & installed.

-=item PERL_JSON_BACKEND = 'JSON::backportPP'

-Always use JSON::backportPP.

-JSON::backportPP is JSON::PP back port module.

-C<JSON> includes JSON::backportPP instead of JSON::PP.

-=back

-These ideas come from L<DBI::PurePerl> mechanism.

-example:

- BEGIN { $ENV{PERL_JSON_BACKEND} = 'JSON::PP' }

- use JSON; # always uses JSON::PP

-In future, it may be able to specify another module.

-=head1 USE PP FEATURES EVEN THOUGH XS BACKEND

-Many methods are available with either JSON::XS or JSON::PP and

-when the backend module is JSON::XS, if any JSON::PP specific (i.e. JSON::XS unsupported)

-method is called, it will C<warn> and be noop.

-But If you C<use> C<JSON> passing the optional string C<-support_by_pp>,

-it makes a part of those unsupported methods available.

-This feature is achieved by using JSON::PP in C<de/encode>.

- BEGIN { $ENV{PERL_JSON_BACKEND} = 2 } # with JSON::XS

- use JSON -support_by_pp;

- my $json = JSON->new;

- $json->allow_nonref->escape_slash->encode("/");

-At this time, the returned object is a C<JSON::Backend::XS::Supportable>

-object (re-blessed XS object), and by checking JSON::XS unsupported flags

-in de/encoding, can support some unsupported methods - C<loose>, C<allow_bignum>,

-C<allow_barekey>, C<allow_singlequote>, C<escape_slash> and C<indent_length>.

-When any unsupported methods are not enable, C<XS de/encode> will be

-used as is. The switch is achieved by changing the symbolic tables.

-C<-support_by_pp> is effective only when the backend module is JSON::XS

-and it makes the de/encoding speed down a bit.

-See to L<JSON::PP SUPPORT METHODS>.

-=head1 INCOMPATIBLE CHANGES TO OLD VERSION

-There are big incompatibility between new version (2.00) and old (1.xx).

-If you use old C<JSON> 1.xx in your code, please check it.

-See to L<Transition ways from 1.xx to 2.xx.>

-=over

-=item jsonToObj and objToJson are obsoleted.

-Non Perl-style name C<jsonToObj> and C<objToJson> are obsoleted

-(but not yet deleted from the source).

-If you use these functions in your code, please replace them

-with C<from_json> and C<to_json>.

-=item Global variables are no longer available.

-C<JSON> class variables - C<$JSON::AUTOCONVERT>, C<$JSON::BareKey>, etc...

-- are not available any longer.

-Instead, various features can be used through object methods.

-=item Package JSON::Converter and JSON::Parser are deleted.

-Now C<JSON> bundles with JSON::PP which can handle JSON more properly than them.

-=item Package JSON::NotString is deleted.

-There was C<JSON::NotString> class which represents JSON value C<true>, C<false>, C<null>

-and numbers. It was deleted and replaced by C<JSON::Boolean>.

-C<JSON::Boolean> represents C<true> and C<false>.

-C<JSON::Boolean> does not represent C<null>.

-C<JSON::null> returns C<undef>.

-C<JSON> makes L<JSON::XS::Boolean> and L<JSON::PP::Boolean> is-a relation

-to L<JSON::Boolean>.

-=item function JSON::Number is obsoleted.

-C<JSON::Number> is now needless because JSON::XS and JSON::PP have

-round-trip integrity.

-=item JSONRPC modules are deleted.

-Perl implementation of JSON-RPC protocol - C<JSONRPC >, C<JSONRPC::Transport::HTTP>

-and C<Apache::JSONRPC > are deleted in this distribution.

-Instead of them, there is L<JSON::RPC> which supports JSON-RPC protocol version 1.1.

-=back

-=head2 Transition ways from 1.xx to 2.xx.

-You should set C<suport_by_pp> mode firstly, because

-it is always successful for the below codes even with JSON::XS.

- use JSON -support_by_pp;

-=over

-=item Exported jsonToObj (simple)

- from_json($json_text);

-=item Exported objToJson (simple)

- to_json($perl_scalar);

-=item Exported jsonToObj (advanced)

- $flags = {allow_barekey => 1, allow_singlequote => 1};

- from_json($json_text, $flags);

-equivalent to:

- $JSON::BareKey = 1;

- $JSON::QuotApos = 1;

- jsonToObj($json_text);

-=item Exported objToJson (advanced)

- $flags = {allow_blessed => 1, allow_barekey => 1};

- to_json($perl_scalar, $flags);

-equivalent to:

- $JSON::BareKey = 1;

- objToJson($perl_scalar);

-=item jsonToObj as object method

- $json->decode($json_text);

-=item objToJson as object method

- $json->encode($perl_scalar);

-=item new method with parameters

-The C<new> method in 2.x takes any parameters no longer.

-You can set parameters instead;

- $json = JSON->new->pretty;

-=item $JSON::Pretty, $JSON::Indent, $JSON::Delimiter

-If C<indent> is enable, that means C<$JSON::Pretty> flag set. And

-C<$JSON::Delimiter> was substituted by C<space_before> and C<space_after>.

-In conclusion:

- $json->indent->space_before->space_after;

-Equivalent to:

- $json->pretty;

-To change indent length, use C<indent_length>.

-(Only with JSON::PP, if C<-support_by_pp> is not used.)

- $json->pretty->indent_length(2)->encode($perl_scalar);

-=item $JSON::BareKey

-(Only with JSON::PP, if C<-support_by_pp> is not used.)

- $json->allow_barekey->decode($json_text)

-=item $JSON::ConvBlessed

-use C<-convert_blessed_universally>. See to L<convert_blessed>.

-=item $JSON::QuotApos

-(Only with JSON::PP, if C<-support_by_pp> is not used.)

- $json->allow_singlequote->decode($json_text)

-=item $JSON::SingleQuote

-Disable. C<JSON> does not make such a invalid JSON string any longer.

-=item $JSON::KeySort

- $json->canonical->encode($perl_scalar)

-This is the ascii sort.

-If you want to use with your own sort routine, check the C<sort_by> method.

-(Only with JSON::PP, even if C<-support_by_pp> is used currently.)

- $json->sort_by($sort_routine_ref)->encode($perl_scalar)

- $json->sort_by(sub { $JSON::PP::a <=> $JSON::PP::b })->encode($perl_scalar)

-Can't access C<$a> and C<$b> but C<$JSON::PP::a> and C<$JSON::PP::b>.

-=item $JSON::SkipInvalid

- $json->allow_unknown

-=item $JSON::AUTOCONVERT

-Needless. C<JSON> backend modules have the round-trip integrity.

-=item $JSON::UTF8

-Needless because C<JSON> (JSON::XS/JSON::PP) sets

-the UTF8 flag on properly.

- # With UTF8-flagged strings

- $json->allow_nonref;

- $str = chr(1000); # UTF8-flagged

- $json_text = $json->utf8(0)->encode($str);

- utf8::is_utf8($json_text);

- # true

- $json_text = $json->utf8(1)->encode($str);

- utf8::is_utf8($json_text);

- # false

- $str = '"' . chr(1000) . '"'; # UTF8-flagged

- $perl_scalar = $json->utf8(0)->decode($str);

- utf8::is_utf8($perl_scalar);

- # true

- $perl_scalar = $json->utf8(1)->decode($str);

- # died because of 'Wide character in subroutine'

-See to L<JSON::XS/A FEW NOTES ON UNICODE AND PERL>.

-=item $JSON::UnMapping

-Disable. See to L<MAPPING>.

-=item $JSON::SelfConvert

-This option was deleted.

-Instead of it, if a given blessed object has the C<TO_JSON> method,

-C<TO_JSON> will be executed with C<convert_blessed>.

- $json->convert_blessed->encode($blessed_hashref_or_arrayref)

- # if need, call allow_blessed

-Note that it was C<toJson> in old version, but now not C<toJson> but C<TO_JSON>.

-=back

-=head1 TODO

-=over

-=item example programs

-=back

-=head1 THREADS

-No test with JSON::PP. If with JSON::XS, See to L<JSON::XS/THREADS>.

-=head1 BUGS

-Please report bugs relevant to C<JSON> to E<lt>makamaka[at]cpan.orgE<gt>.

-=head1 SEE ALSO

-Most of the document is copied and modified from JSON::XS doc.

-L<JSON::XS>, L<JSON::PP>

-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

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

-it under the same terms as Perl itself.

-=cut