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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.140 by root, Thu Jun 27 11:45:17 2013 UTC vs.
Revision 1.147 by root, Tue Oct 29 00:19:08 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 $VERSION = '3.0';
107	our @ISA = qw(Exporter);	107	our @ISA = qw(Exporter);
108		108
109	our @EXPORT = qw(encode_json decode_json to_json from_json);	109	our @EXPORT = qw(encode_json decode_json);
110
111	sub to_json($) {
112	require Carp;
113	Carp::croak ("JSON::XS::to_json has been renamed to encode_json, either downgrade to pre-2.0 versions of JSON::XS or rename the call");
114	}
115
116	sub from_json($) {
117	require Carp;
118	Carp::croak ("JSON::XS::from_json has been renamed to decode_json, either downgrade to pre-2.0 versions of JSON::XS or rename the call");
119	}
120		110
121	use Exporter;	111	use Exporter;
122	use XSLoader;	112	use XSLoader;
		113
		114	use Types::Serialiser ();
123		115
124	=head1 FUNCTIONAL INTERFACE	116	=head1 FUNCTIONAL INTERFACE
125		117
126	The following convenience methods are provided by this module. They are	118	The following convenience methods are provided by this module. They are
127	exported by default:	119	exported by default:
…		…
148	This function call is functionally identical to:	140	This function call is functionally identical to:
149		141
150	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)	142	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)
151		143
152	Except being faster.	144	Except being faster.
153
154	=item $is_boolean = JSON::XS::is_bool $scalar
155
156	Returns true if the passed scalar represents either JSON::XS::true or
157	JSON::XS::false, two constants that act like C<1> and C<0>, respectively
158	and are used to represent JSON C<true> and C<false> values in Perl.
159
160	See MAPPING, below, for more information on how JSON values are mapped to
161	Perl.
162		145
163	=back	146	=back
164		147
165		148
166	=head1 A FEW NOTES ON UNICODE AND PERL	149	=head1 A FEW NOTES ON UNICODE AND PERL
…		…
484		467
485	=item $json = $json->allow_blessed ([$enable])	468	=item $json = $json->allow_blessed ([$enable])
486		469
487	=item $enabled = $json->get_allow_blessed	470	=item $enabled = $json->get_allow_blessed
488		471
		472	See L<OBJECT SERIALISATION> for details.
		473
489	If C<$enable> is true (or missing), then the C<encode> method will not	474	If C<$enable> is true (or missing), then the C<encode> method will not
490	barf when it encounters a blessed reference. Instead, the value of the	475	barf when it encounters a blessed reference that it cannot convert
491	B<convert_blessed> option will decide whether C<null> (C<convert_blessed>	476	otherwise. Instead, a JSON C<null> value is encoded instead of the object.
492	disabled or no C<TO_JSON> method found) or a representation of the
493	object (C<convert_blessed> enabled and C<TO_JSON> method found) is being
494	encoded. Has no effect on C<decode>.
495		477
496	If C<$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
497	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>.
498		483
499	=item $json = $json->convert_blessed ([$enable])	484	=item $json = $json->convert_blessed ([$enable])
500		485
501	=item $enabled = $json->get_convert_blessed	486	=item $enabled = $json->get_convert_blessed
		487
		488	See "OBJECT SERIALISATION" for details.
502		489
503	If C<$enable> is true (or missing), then C<encode>, upon encountering a	490	If C<$enable> is true (or missing), then C<encode>, upon encountering a
504	blessed object, will check for the availability of the C<TO_JSON> method	491	blessed object, will check for the availability of the C<TO_JSON> method
505	on the object's class. If found, it will be called in scalar context	492	on the object's class. If found, it will be called in scalar context and
506	and the resulting scalar will be encoded instead of the object. If no	493	the resulting scalar will be encoded instead of the object.
507	C<TO_JSON> method is found, the value of C<allow_blessed> will decide what
508	to do.
509		494
510	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>	495	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>
511	returns other blessed objects, those will be handled in the same	496	returns other blessed objects, those will be handled in the same
512	way. C<TO_JSON> must take care of not causing an endless recursion cycle	497	way. C<TO_JSON> must take care of not causing an endless recursion cycle
513	(== crash) in this case. The name of C<TO_JSON> was chosen because other	498	(== crash) in this case. The name of C<TO_JSON> was chosen because other
514	methods called by the Perl core (== not by the user of the object) are	499	methods called by the Perl core (== not by the user of the object) are
515	usually in upper case letters and to avoid collisions with any C<to_json>	500	usually in upper case letters and to avoid collisions with any C<to_json>
516	function or method.	501	function or method.
517		502
518	This setting does not yet influence C<decode> in any way, but in the	503	If C<$enable> is false (the default), then C<encode> will not consider
519	future, global hooks might get installed that influence C<decode> and are	504	this type of conversion.
520	enabled by this setting.
521		505
522	If C<$enable> is false, then the C<allow_blessed> setting will decide what	506	This setting has no effect on C<decode>.
523	to do when a blessed object is found.	507
		508	=item $json = $json->allow_tags ([$enable])
		509
		510	=item $enabled = $json->allow_tags
		511
		512	See "OBJECT SERIALISATION" for details.
		513
		514	If C<$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.
524		525
525	=item $json = $json->filter_json_object ([$coderef->($hashref)])	526	=item $json = $json->filter_json_object ([$coderef->($hashref)])
526		527
527	When C<$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
528	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
…		…
667		668
668	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.	669	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
669		670
670	=item $json_text = $json->encode ($perl_scalar)	671	=item $json_text = $json->encode ($perl_scalar)
671		672
672	Converts the given Perl data structure (a simple scalar or a reference	673	Converts the given Perl value or data structure to its JSON
673	to a hash or array) to its JSON representation. Simple scalars will be	674	representation. Croaks on error.
674	converted into JSON string or number sequences, while references to arrays
675	become JSON arrays and references to hashes become JSON objects. Undefined
676	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>
677	nor C<false> values will be generated.
678		675
679	=item $perl_scalar = $json->decode ($json_text)	676	=item $perl_scalar = $json->decode ($json_text)
680		677
681	The opposite of C<encode>: expects a JSON text and tries to parse it,	678	The opposite of C<encode>: expects a JSON text and tries to parse it,
682	returning the resulting simple scalar or reference. Croaks on error.	679	returning the resulting simple scalar or reference. Croaks on error.
683
684	JSON numbers and strings become simple Perl scalars. JSON arrays become
685	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes
686	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.
687		680
688	=item ($perl_scalar, $characters) = $json->decode_prefix ($json_text)	681	=item ($perl_scalar, $characters) = $json->decode_prefix ($json_text)
689		682
690	This works like the C<decode> method, but instead of raising an exception	683	This works like the C<decode> method, but instead of raising an exception
691	when there is trailing garbage after the first JSON object, it will	684	when there is trailing garbage after the first JSON object, it will
692	silently stop parsing there and return the number of characters consumed	685	silently stop parsing there and return the number of characters consumed
693	so far.	686	so far.
694		687
695	This is useful if your JSON texts are not delimited by an outer protocol	688	This is useful if your JSON texts are not delimited by an outer protocol
696	(which is not the brightest thing to do in the first place) and you need
697	to know where the JSON text ends.	689	and you need to know where the JSON text ends.
698		690
699	JSON::XS->new->decode_prefix ("[1] the tail")	691	JSON::XS->new->decode_prefix ("[1] the tail")
700	=> ([], 3)	692	=> ([], 3)
701		693
702	=back	694	=back
…		…
796	=back	788	=back
797		789
798	=head2 LIMITATIONS	790	=head2 LIMITATIONS
799		791
800	All options that affect decoding are supported, except	792	All options that affect decoding are supported, except
801	C<allow_nonref>. The reason for this is that it cannot be made to	793	C<allow_nonref>. The reason for this is that it cannot be made to work
802	work sensibly: JSON objects and arrays are self-delimited, i.e. you can concatenate	794	sensibly: JSON objects and arrays are self-delimited, i.e. you can
803	them back to back and still decode them perfectly. This does not hold true	795	concatenate them back to back and still decode them perfectly. This does
804	for JSON numbers, however.	796	not hold true for JSON numbers, however.
805		797
806	For example, is the string C<1> a single JSON number, or is it simply the	798	For example, is the string C<1> a single JSON number, or is it simply the
807	start of C<12>? Or is C<12> a single JSON number, or the concatenation	799	start of C<12>? Or is C<12> a single JSON number, or the concatenation
808	of C<1> and C<2>? In neither case you can tell, and this is why JSON::XS	800	of C<1> and C<2>? In neither case you can tell, and this is why JSON::XS
809	takes the conservative route and disallows this case.	801	takes the conservative route and disallows this case.
…		…
1002	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
1003	the least significant bit.	995	the least significant bit.
1004		996
1005	=item true, false	997	=item true, false
1006		998
1007	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,	999	These JSON atoms become C<Types::Serialiser::true> and
1008	respectively. They are overloaded to act almost exactly like the numbers	1000	C<Types::Serialiser::false>, respectively. They are overloaded to act
1009	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
1010	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).
1011		1004
1012	=item null	1005	=item null
1013		1006
1014	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 "OBJECT SERIALISATION", below, for details.
1015		1023
1016	=back	1024	=back
1017		1025
1018		1026
1019	=head2 PERL -> JSON	1027	=head2 PERL -> JSON
…		…
1024		1032
1025	=over 4	1033	=over 4
1026		1034
1027	=item hash references	1035	=item hash references
1028		1036
1029	Perl hash references become JSON objects. As there is no inherent ordering	1037	Perl hash references become JSON objects. As there is no inherent
1030	in hash keys (or JSON objects), they will usually be encoded in a	1038	ordering in hash keys (or JSON objects), they will usually be encoded
1031	pseudo-random order that can change between runs of the same program but	1039	in a pseudo-random order. JSON::XS can optionally sort the hash keys
1032	stays generally the same within a single run of a program. JSON::XS can	1040	(determined by the I<canonical> flag), so the same datastructure will
1033	optionally sort the hash keys (determined by the I<canonical> flag), so	1041	serialise to the same JSON text (given same settings and version of
1034	the same datastructure will serialise to the same JSON text (given same	1042	JSON::XS), but this incurs a runtime overhead and is only rarely useful,
1035	settings and version of JSON::XS), but this incurs a runtime overhead	1043	e.g. when you want to compare some JSON text against another for equality.
1036	and is only rarely useful, e.g. when you want to compare some JSON text
1037	against another for equality.
1038		1044
1039	=item array references	1045	=item array references
1040		1046
1041	Perl array references become JSON arrays.	1047	Perl array references become JSON arrays.
1042		1048
1043	=item other references	1049	=item other references
1044		1050
1045	Other unblessed references are generally not allowed and will cause an	1051	Other unblessed references are generally not allowed and will cause an
1046	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
1047	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.
1048	also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability.
1049		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;
1050	encode_json [\0, JSON::XS::true] # yields [false,true]	1060	encode_json [\0, Types::Serialiser::true] # yields [false,true]
1051		1061
1052	=item JSON::XS::true, JSON::XS::false	1062	=item Types::Serialiser::true, Types::Serialiser::false
1053		1063
1054	These special values become JSON true and JSON false values,	1064	These special values from the L<Types::Serialiser> module become JSON true
1055	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.
1056		1067
1057	=item blessed objects	1068	=item blessed objects
1058		1069
1059	Blessed objects are not directly representable in JSON. See the	1070	Blessed objects are not directly representable in JSON, but C<JSON::XS>
1060	C<allow_blessed> and C<convert_blessed> methods on various options on	1071	allows various ways of handling objects. See "OBJECT SERIALISATION",
1061	how to deal with this: basically, you can choose between throwing an	1072	below, for details.
1062	exception, encoding the reference as if it weren't blessed, or provide
1063	your own serialiser method.
1064		1073
1065	=item simple scalars	1074	=item simple scalars
1066		1075
1067	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
1068	difficult objects to encode: JSON::XS will encode undefined scalars as	1077	difficult objects to encode: JSON::XS will encode undefined scalars as
…		…
1104	extensions to the floating point numbers of your platform, such as	1113	extensions to the floating point numbers of your platform, such as
1105	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
1106	error to pass those in.	1115	error to pass those in.
1107		1116
1108	=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 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}, $self->{id})
		1157	}
		1158
		1159	=item 2. C<convert_blessed> is enabled and object has a C<TO_JSON> method.
		1160
		1161	In this case, the C<TO_JSON> method of the object is invoked in scalar
		1162	context. It must return a single scalar that can be directly encoded into
		1163	JSON. This scalar replaces the object in the JSON text.
		1164
		1165	For example, the following C<TO_JSON> method will convert all L<URI>
		1166	objects to JSON strings when serialised. The fatc that these values
		1167	originally were L<URI> objects is lost.
		1168
		1169	sub URI::TO_JSON {
		1170	my ($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	}
1109		1220
1110		1221
1111	=head1 ENCODING/CODESET FLAG NOTES	1222	=head1 ENCODING/CODESET FLAG NOTES
1112		1223
1113	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
…		…
1436	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
1437	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
1438	security right).	1549	security right).
1439		1550
1440		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
1441	=head1 THREADS	1560	=head1 THREADS
1442		1561
1443	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
1444	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
1445	horribly slow so-called "threads" which are simply slow and bloated	1564	horribly slow so-called "threads" which are simply slow and bloated
…		…
1475	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
1476	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.
1477		1596
1478	=cut	1597	=cut
1479		1598
1480	our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" };	1599	BEGIN {
1481	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;
1482		1605
1483	sub true() { $true }	1606	JSON::XS::Boolean:: = Types::Serialiser::Boolean::;
1484	sub false() { $false }
1485
1486	sub is_bool($) {
1487	UNIVERSAL::isa $_[0], "JSON::XS::Boolean"
1488	# or UNIVERSAL::isa $_[0], "JSON::Literal"
1489	}	1607	}
1490		1608
1491	XSLoader::load "JSON::XS", $VERSION;	1609	XSLoader::load "JSON::XS", $VERSION;
1492
1493	package JSON::XS::Boolean;
1494
1495	use overload
1496	"0+" => sub { ${$_[0]} },
1497	"++" => sub { $_[0] = ${$_[0]} + 1 },
1498	"--" => sub { $_[0] = ${$_[0]} - 1 },
1499	fallback => 1;
1500
1501	1;
1502		1610
1503	=head1 SEE ALSO	1611	=head1 SEE ALSO
1504		1612
1505	The F<json_xs> command line utility for quick experiments.	1613	The F<json_xs> command line utility for quick experiments.
1506		1614
…		…
1509	Marc Lehmann <schmorp@schmorp.de>	1617	Marc Lehmann <schmorp@schmorp.de>
1510	http://home.schmorp.de/	1618	http://home.schmorp.de/
1511		1619
1512	=cut	1620	=cut
1513		1621
		1622	1
		1623

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Comparing JSON-XS/XS.pm (file contents): Revision 1.140 by root, Thu Jun 27 11:45:17 2013 UTC vs. Revision 1.147 by root, Tue Oct 29 00:19:08 2013 UTC

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Comparing JSON-XS/XS.pm (file contents):
Revision 1.140 by root, Thu Jun 27 11:45:17 2013 UTC vs.
Revision 1.147 by root, Tue Oct 29 00:19:08 2013 UTC