[ViewVC] Diff of: cvs/JSON-XS/XS.pm

Comparing JSON-XS/XS.pm (file contents):
Revision 1.143 by root, Fri Oct 25 20:02:54 2013 UTC vs.
Revision 1.149 by root, Tue Oct 29 00:21:10 2013 UTC

…		…
101		101
102	package JSON::XS;	102	package JSON::XS;
103		103
104	use common::sense;	104	use common::sense;
105		105
106	our $VERSION = 2.34;	106	our $VERSION = '3.0';
107	our @ISA = qw(Exporter);	107	our @ISA = qw(Exporter);
108		108
109	our @EXPORT = qw(encode_json decode_json);	109	our @EXPORT = qw(encode_json decode_json);
110		110
111	use Exporter;	111	use Exporter;
112	use XSLoader;	112	use XSLoader;
		113
		114	use Types::Serialiser ();
113		115
114	=head1 FUNCTIONAL INTERFACE	116	=head1 FUNCTIONAL INTERFACE
115		117
116	The following convenience methods are provided by this module. They are	118	The following convenience methods are provided by this module. They are
117	exported by default:	119	exported by default:
…		…
138	This function call is functionally identical to:	140	This function call is functionally identical to:
139		141
140	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)	142	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)
141		143
142	Except being faster.	144	Except being faster.
143
144	=item $is_boolean = JSON::XS::is_bool $scalar
145
146	Returns true if the passed scalar represents either JSON::XS::true or
147	JSON::XS::false, two constants that act like C<1> and C<0>, respectively
148	and are used to represent JSON C<true> and C<false> values in Perl.
149
150	See MAPPING, below, for more information on how JSON values are mapped to
151	Perl.
152		145
153	=back	146	=back
154		147
155		148
156	=head1 A FEW NOTES ON UNICODE AND PERL	149	=head1 A FEW NOTES ON UNICODE AND PERL
…		…
474		467
475	=item $json = $json->allow_blessed ([$enable])	468	=item $json = $json->allow_blessed ([$enable])
476		469
477	=item $enabled = $json->get_allow_blessed	470	=item $enabled = $json->get_allow_blessed
478		471
		472	See L<OBJECT SERIALISATION> for details.
		473
479	If C<$enable> is true (or missing), then the C<encode> method will not	474	If C<$enable> is true (or missing), then the C<encode> method will not
480	barf when it encounters a blessed reference. Instead, the value of the	475	barf when it encounters a blessed reference that it cannot convert
481	B<convert_blessed> option will decide whether C<null> (C<convert_blessed>	476	otherwise. Instead, a JSON C<null> value is encoded instead of the object.
482	disabled or no C<TO_JSON> method found) or a representation of the
483	object (C<convert_blessed> enabled and C<TO_JSON> method found) is being
484	encoded. Has no effect on C<decode>.
485		477
486	If C<$enable> is false (the default), then C<encode> will throw an	478	If C<$enable> is false (the default), then C<encode> will throw an
487	exception when it encounters a blessed object.	479	exception when it encounters a blessed object that it cannot convert
		480	otherwise.
		481
		482	This setting has no effect on C<decode>.
488		483
489	=item $json = $json->convert_blessed ([$enable])	484	=item $json = $json->convert_blessed ([$enable])
490		485
491	=item $enabled = $json->get_convert_blessed	486	=item $enabled = $json->get_convert_blessed
		487
		488	See L<OBJECT SERIALISATION> for details.
492		489
493	If C<$enable> is true (or missing), then C<encode>, upon encountering a	490	If C<$enable> is true (or missing), then C<encode>, upon encountering a
494	blessed object, will check for the availability of the C<TO_JSON> method	491	blessed object, will check for the availability of the C<TO_JSON> method
495	on the object's class. If found, it will be called in scalar context	492	on the object's class. If found, it will be called in scalar context and
496	and the resulting scalar will be encoded instead of the object. If no	493	the resulting scalar will be encoded instead of the object.
497	C<TO_JSON> method is found, the value of C<allow_blessed> will decide what
498	to do.
499		494
500	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>	495	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>
501	returns other blessed objects, those will be handled in the same	496	returns other blessed objects, those will be handled in the same
502	way. C<TO_JSON> must take care of not causing an endless recursion cycle	497	way. C<TO_JSON> must take care of not causing an endless recursion cycle
503	(== crash) in this case. The name of C<TO_JSON> was chosen because other	498	(== crash) in this case. The name of C<TO_JSON> was chosen because other
504	methods called by the Perl core (== not by the user of the object) are	499	methods called by the Perl core (== not by the user of the object) are
505	usually in upper case letters and to avoid collisions with any C<to_json>	500	usually in upper case letters and to avoid collisions with any C<to_json>
506	function or method.	501	function or method.
507		502
508	This setting does not yet influence C<decode> in any way, but in the	503	If C<$enable> is false (the default), then C<encode> will not consider
509	future, global hooks might get installed that influence C<decode> and are	504	this type of conversion.
510	enabled by this setting.
511		505
512	If C<$enable> is false, then the C<allow_blessed> setting will decide what	506	This setting has no effect on C<decode>.
513	to do when a blessed object is found.	507
		508	=item $json = $json->allow_tags ([$enable])
		509
		510	=item $enabled = $json->allow_tags
		511
		512	See L<OBJECT SERIALISATION> for details.
		513
		514	If C<$enable> is true (or missing), then C<encode>, upon encountering a
		515	blessed object, will check for the availability of the C<FREEZE> method on
		516	the object's class. If found, it will be used to serialise the object into
		517	a nonstandard tagged JSON value (that JSON decoders cannot decode).
		518
		519	It also causes C<decode> to parse such tagged JSON values and deserialise
		520	them via a call to the C<THAW> method.
		521
		522	If C<$enable> is false (the default), then C<encode> will not consider
		523	this type of conversion, and tagged JSON values will cause a parse error
		524	in C<decode>, as if tags were not part of the grammar.
514		525
515	=item $json = $json->filter_json_object ([$coderef->($hashref)])	526	=item $json = $json->filter_json_object ([$coderef->($hashref)])
516		527
517	When C<$coderef> is specified, it will be called from C<decode> each	528	When C<$coderef> is specified, it will be called from C<decode> each
518	time it decodes a JSON object. The only argument is a reference to the	529	time it decodes a JSON object. The only argument is a reference to the
…		…
983	floating point, JSON::XS only guarantees precision up to but not including	994	floating point, JSON::XS only guarantees precision up to but not including
984	the least significant bit.	995	the least significant bit.
985		996
986	=item true, false	997	=item true, false
987		998
988	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,	999	These JSON atoms become C<Types::Serialiser::true> and
989	respectively. They are overloaded to act almost exactly like the numbers	1000	C<Types::Serialiser::false>, respectively. They are overloaded to act
990	C<1> and C<0>. You can check whether a scalar is a JSON boolean by using	1001	almost exactly like the numbers C<1> and C<0>. You can check whether
991	the C<JSON::XS::is_bool> function.	1002	a scalar is a JSON boolean by using the C<Types::Serialiser::is_bool>
		1003	function (after C<use Types::Serialier>, of course).
992		1004
993	=item null	1005	=item null
994		1006
995	A JSON null atom becomes C<undef> in Perl.	1007	A JSON null atom becomes C<undef> in Perl.
		1008
		1009	=item shell-style comments (C<< # I<text> >>)
		1010
		1011	As a nonstandard extension to the JSON syntax that is enabled by the
		1012	C<relaxed> setting, shell-style comments are allowed. They can start
		1013	anywhere outside strings and go till the end of the line.
		1014
		1015	=item tagged values (C<< (I<tag>)I<value> >>).
		1016
		1017	Another nonstandard extension to the JSON syntax, enabled with the
		1018	C<allow_tags> setting, are tagged values. In this implementation, the
		1019	I<tag> must be a perl package/class name encoded as a JSON string, and the
		1020	I<value> must be a JSON array encoding optional constructor arguments.
		1021
		1022	See L<OBJECT SERIALISATION>, below, for details.
996		1023
997	=back	1024	=back
998		1025
999		1026
1000	=head2 PERL -> JSON	1027	=head2 PERL -> JSON
…		…
1021		1048
1022	=item other references	1049	=item other references
1023		1050
1024	Other unblessed references are generally not allowed and will cause an	1051	Other unblessed references are generally not allowed and will cause an
1025	exception to be thrown, except for references to the integers C<0> and	1052	exception to be thrown, except for references to the integers C<0> and
1026	C<1>, which get turned into C<false> and C<true> atoms in JSON. You can	1053	C<1>, which get turned into C<false> and C<true> atoms in JSON.
1027	also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability.
1028		1054
		1055	Since C<JSON::XS> uses the boolean model from L<Types::Serialiser>, you
		1056	can also C<use Types::Serialiser> and then use C<Types::Serialiser::false>
		1057	and C<Types::Serialiser::true> to improve readability.
		1058
		1059	use Types::Serialiser;
1029	encode_json [\0, JSON::XS::true] # yields [false,true]	1060	encode_json [\0, Types::Serialiser::true] # yields [false,true]
1030		1061
1031	=item JSON::XS::true, JSON::XS::false	1062	=item Types::Serialiser::true, Types::Serialiser::false
1032		1063
1033	These special values become JSON true and JSON false values,	1064	These special values from the L<Types::Serialiser> module become JSON true
1034	respectively. You can also use C<\1> and C<\0> directly if you want.	1065	and JSON false values, respectively. You can also use C<\1> and C<\0>
		1066	directly if you want.
1035		1067
1036	=item blessed objects	1068	=item blessed objects
1037		1069
1038	Blessed objects are not directly representable in JSON. See the	1070	Blessed objects are not directly representable in JSON, but C<JSON::XS>
1039	C<allow_blessed> and C<convert_blessed> methods on various options on	1071	allows various ways of handling objects. See L<OBJECT SERIALISATION>,
1040	how to deal with this: basically, you can choose between throwing an	1072	below, for details.
1041	exception, encoding the reference as if it weren't blessed, or provide
1042	your own serialiser method.
1043		1073
1044	=item simple scalars	1074	=item simple scalars
1045		1075
1046	Simple Perl scalars (any scalar that is not a reference) are the most	1076	Simple Perl scalars (any scalar that is not a reference) are the most
1047	difficult objects to encode: JSON::XS will encode undefined scalars as	1077	difficult objects to encode: JSON::XS will encode undefined scalars as
…		…
1083	extensions to the floating point numbers of your platform, such as	1113	extensions to the floating point numbers of your platform, such as
1084	infinities or NaN's - these cannot be represented in JSON, and it is an	1114	infinities or NaN's - these cannot be represented in JSON, and it is an
1085	error to pass those in.	1115	error to pass those in.
1086		1116
1087	=back	1117	=back
		1118
		1119	=head2 OBJECT SERIALISATION
		1120
		1121	As JSON cannot directly represent Perl objects, you have to choose between
		1122	a pure JSON representation (without the ability to deserialise the object
		1123	automatically again), and a nonstandard extension to the JSON syntax,
		1124	tagged values.
		1125
		1126	=head3 SERIALISATION
		1127
		1128	What happens when C<JSON::XS> encounters a Perl object depends on the
		1129	C<allow_blessed>, C<convert_blessed> and C<allow_tags> settings, which are
		1130	used in this order:
		1131
		1132	=over 4
		1133
		1134	=item 1. C<allow_tags> is enabled and the object has a C<FREEZE> method.
		1135
		1136	In this case, C<JSON::XS> uses the L<Types::Serialiser> object
		1137	serialisation protocol to create a tagged JSON value, using a nonstandard
		1138	extension to the JSON syntax.
		1139
		1140	This works by invoking the C<FREEZE> method on the object, with the first
		1141	argument being the object to serialise, and the second argument being the
		1142	constant string C<JSON> to distinguish it from other serialisers.
		1143
		1144	The C<FREEZE> method can return any number of values (i.e. zero or
		1145	more). These values and the paclkage/classname of the object will then be
		1146	encoded as a tagged JSON value in the following format:
		1147
		1148	("classname")[FREEZE return values...]
		1149
		1150	For example, the hypothetical C<My::Object> C<FREEZE> method might use the
		1151	objects C<type> and C<id> members to encode the object:
		1152
		1153	sub My::Object::FREEZE {
		1154	my ($self, $serialiser) = @_;
		1155
		1156	($self->{type}, $self->{id})
		1157	}
		1158
		1159	=item 2. C<convert_blessed> is enabled and the object has a C<TO_JSON> method.
		1160
		1161	In this case, the C<TO_JSON> method of the object is invoked in scalar
		1162	context. It must return a single scalar that can be directly encoded into
		1163	JSON. This scalar replaces the object in the JSON text.
		1164
		1165	For example, the following C<TO_JSON> method will convert all L<URI>
		1166	objects to JSON strings when serialised. The fatc that these values
		1167	originally were L<URI> objects is lost.
		1168
		1169	sub URI::TO_JSON {
		1170	my ($uri) = @_;
		1171	$uri->as_string
		1172	}
		1173
		1174	=item 3. C<allow_blessed> is enabled.
		1175
		1176	The object will be serialised as a JSON null value.
		1177
		1178	=item 4. none of the above
		1179
		1180	If none of the settings are enabled or the respective methods are missing,
		1181	C<JSON::XS> throws an exception.
		1182
		1183	=back
		1184
		1185	=head3 DESERIALISATION
		1186
		1187	For deserialisation there are only two cases to consider: either
		1188	nonstandard tagging was used, in which case C<allow_tags> decides,
		1189	or objects cannot be automatically be deserialised, in which
		1190	case you can use postprocessing or the C<filter_json_object> or
		1191	C<filter_json_single_key_object> callbacks to get some real objects our of
		1192	your JSON.
		1193
		1194	This section only considers the tagged value case: I a tagged JSON object
		1195	is encountered during decoding and C<allow_tags> is disabled, a parse
		1196	error will result (as if tagged values were not part of the grammar).
		1197
		1198	If C<allow_tags> is enabled, C<JSON::XS> will look up the C<THAW> method
		1199	of the package/classname used during serialisation (it will not attempt
		1200	to load the package as a Perl module). If there is no such method, the
		1201	decoding will fail with an error.
		1202
		1203	Otherwise, the C<THAW> method is invoked with the classname as first
		1204	argument, the constant string C<JSON> as second argument, and all the
		1205	values from the JSON array (the values originally returned by the
		1206	C<FREEZE> method) as remaining arguments.
		1207
		1208	The method must then return the object. While technically you can return
		1209	any Perl scalar, you might have to enable the C<enable_nonref> setting to
		1210	make that work in all cases, so better return an actual blessed reference.
		1211
		1212	As an example, let's implement a C<THAW> function that regenerates the
		1213	C<My::Object> from the C<FREEZE> example earlier:
		1214
		1215	sub My::Object::THAW {
		1216	my ($class, $serialiser, $type, $id) = @_;
		1217
		1218	$class->new (type => $type, id => $id)
		1219	}
1088		1220
1089		1221
1090	=head1 ENCODING/CODESET FLAG NOTES	1222	=head1 ENCODING/CODESET FLAG NOTES
1091		1223
1092	The interested reader might have seen a number of flags that signify	1224	The interested reader might have seen a number of flags that signify
…		…
1415	are browser design bugs, but it is still you who will have to deal with	1547	are browser design bugs, but it is still you who will have to deal with
1416	it, as major browser developers care only for features, not about getting	1548	it, as major browser developers care only for features, not about getting
1417	security right).	1549	security right).
1418		1550
1419		1551
		1552	=head1 INTEROPERABILITY WITH OTHER MODULES
		1553
		1554	C<JSON::XS> uses the L<Types::Serialiser> module to provide boolean
		1555	constants. That means that the JSON true and false values will be
		1556	comaptible to true and false values of iother modules that do the same,
		1557	such as L<JSON::PP> and L<CBOR::XS>.
		1558
		1559
1420	=head1 THREADS	1560	=head1 THREADS
1421		1561
1422	This module is I<not> guaranteed to be thread safe and there are no	1562	This module is I<not> guaranteed to be thread safe and there are no
1423	plans to change this until Perl gets thread support (as opposed to the	1563	plans to change this until Perl gets thread support (as opposed to the
1424	horribly slow so-called "threads" which are simply slow and bloated	1564	horribly slow so-called "threads" which are simply slow and bloated
…		…
1454	Please refrain from using rt.cpan.org or any other bug reporting	1594	Please refrain from using rt.cpan.org or any other bug reporting
1455	service. I put the contact address into my modules for a reason.	1595	service. I put the contact address into my modules for a reason.
1456		1596
1457	=cut	1597	=cut
1458		1598
1459	our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" };	1599	BEGIN {
1460	our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" };	1600	*true = \$Types::Serialiser::true;
		1601	*true = \&Types::Serialiser::true;
		1602	*false = \$Types::Serialiser::false;
		1603	*false = \&Types::Serialiser::false;
		1604	*is_bool = \&Types::Serialiser::is_bool;
1461		1605
1462	sub true() { $true }	1606	JSON::XS::Boolean:: = Types::Serialiser::Boolean::;
1463	sub false() { $false }
1464
1465	sub is_bool($) {
1466	UNIVERSAL::isa $_[0], "JSON::XS::Boolean"
1467	# or UNIVERSAL::isa $_[0], "JSON::Literal"
1468	}	1607	}
1469		1608
1470	XSLoader::load "JSON::XS", $VERSION;	1609	XSLoader::load "JSON::XS", $VERSION;
1471
1472	package JSON::XS::Boolean;
1473
1474	use overload
1475	"0+" => sub { ${$_[0]} },
1476	"++" => sub { $_[0] = ${$_[0]} + 1 },
1477	"--" => sub { $_[0] = ${$_[0]} - 1 },
1478	fallback => 1;
1479
1480	1;
1481		1610
1482	=head1 SEE ALSO	1611	=head1 SEE ALSO
1483		1612
1484	The F<json_xs> command line utility for quick experiments.	1613	The F<json_xs> command line utility for quick experiments.
1485		1614
…		…
1488	Marc Lehmann <schmorp@schmorp.de>	1617	Marc Lehmann <schmorp@schmorp.de>
1489	http://home.schmorp.de/	1618	http://home.schmorp.de/
1490		1619
1491	=cut	1620	=cut
1492		1621
		1622	1
		1623

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Comparing JSON-XS/XS.pm (file contents): Revision 1.143 by root, Fri Oct 25 20:02:54 2013 UTC vs. Revision 1.149 by root, Tue Oct 29 00:21:10 2013 UTC

Diff Legend

Comparing JSON-XS/XS.pm (file contents):
Revision 1.143 by root, Fri Oct 25 20:02:54 2013 UTC vs.
Revision 1.149 by root, Tue Oct 29 00:21:10 2013 UTC