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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.139 by root, Thu May 23 09:31:32 2013 UTC vs.
Revision 1.155 by root, Mon Nov 24 18:42:51 2014 UTC

…		…
83	this module usually compares favourably in terms of speed, too.	83	this module usually compares favourably in terms of speed, too.
84		84
85	=item * simple to use	85	=item * simple to use
86		86
87	This module has both a simple functional interface as well as an object	87	This module has both a simple functional interface as well as an object
88	oriented interface interface.	88	oriented interface.
89		89
90	=item * reasonably versatile output formats	90	=item * reasonably versatile output formats
91		91
92	You can choose between the most compact guaranteed-single-line format	92	You can choose between the most compact guaranteed-single-line format
93	possible (nice for simple line-based protocols), a pure-ASCII format	93	possible (nice for simple line-based protocols), a pure-ASCII format
…		…
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 $VERSION = 3.01;
107	our @ISA = qw(Exporter);	107	our @ISA = qw(Exporter);
108		108
109	our @EXPORT = qw(encode_json decode_json to_json from_json);	109	our @EXPORT = qw(encode_json decode_json);
110
111	sub to_json($) {
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
…		…
421	[	404	[
422	1, # this comment not allowed in JSON	405	1, # this comment not allowed in JSON
423	# neither this one...	406	# neither this one...
424	]	407	]
425		408
		409	=item * literal ASCII TAB characters in strings
		410
		411	Literal ASCII TAB characters are now allowed in strings (and treated as
		412	C<\t>).
		413
		414	[
		415	"Hello\tWorld",
		416	"Hello<TAB>World", # literal <TAB> would not normally be allowed
		417	]
		418
426	=back	419	=back
427		420
428	=item $json = $json->canonical ([$enable])	421	=item $json = $json->canonical ([$enable])
429		422
430	=item $enabled = $json->get_canonical	423	=item $enabled = $json->get_canonical
…		…
484		477
485	=item $json = $json->allow_blessed ([$enable])	478	=item $json = $json->allow_blessed ([$enable])
486		479
487	=item $enabled = $json->get_allow_blessed	480	=item $enabled = $json->get_allow_blessed
488		481
		482	See L<OBJECT SERIALISATION> for details.
		483
489	If C<$enable> is true (or missing), then the C<encode> method will not	484	If C<$enable> is true (or missing), then the C<encode> method will not
490	barf when it encounters a blessed reference. Instead, the value of the	485	barf when it encounters a blessed reference that it cannot convert
491	B<convert_blessed> option will decide whether C<null> (C<convert_blessed>	486	otherwise. Instead, a JSON C<null> value is encoded instead of the object.
492	disabled or no C<TO_JSON> method found) or a representation of the
493	object (C<convert_blessed> enabled and C<TO_JSON> method found) is being
494	encoded. Has no effect on C<decode>.
495		487
496	If C<$enable> is false (the default), then C<encode> will throw an	488	If C<$enable> is false (the default), then C<encode> will throw an
497	exception when it encounters a blessed object.	489	exception when it encounters a blessed object that it cannot convert
		490	otherwise.
		491
		492	This setting has no effect on C<decode>.
498		493
499	=item $json = $json->convert_blessed ([$enable])	494	=item $json = $json->convert_blessed ([$enable])
500		495
501	=item $enabled = $json->get_convert_blessed	496	=item $enabled = $json->get_convert_blessed
		497
		498	See L<OBJECT SERIALISATION> for details.
502		499
503	If C<$enable> is true (or missing), then C<encode>, upon encountering a	500	If C<$enable> is true (or missing), then C<encode>, upon encountering a
504	blessed object, will check for the availability of the C<TO_JSON> method	501	blessed object, will check for the availability of the C<TO_JSON> method
505	on the object's class. If found, it will be called in scalar context	502	on the object's class. If found, it will be called in scalar context and
506	and the resulting scalar will be encoded instead of the object. If no	503	the resulting scalar will be encoded instead of the object.
507	C<TO_JSON> method is found, the value of C<allow_blessed> will decide what
508	to do.
509		504
510	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>	505	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>
511	returns other blessed objects, those will be handled in the same	506	returns other blessed objects, those will be handled in the same
512	way. C<TO_JSON> must take care of not causing an endless recursion cycle	507	way. C<TO_JSON> must take care of not causing an endless recursion cycle
513	(== crash) in this case. The name of C<TO_JSON> was chosen because other	508	(== crash) in this case. The name of C<TO_JSON> was chosen because other
514	methods called by the Perl core (== not by the user of the object) are	509	methods called by the Perl core (== not by the user of the object) are
515	usually in upper case letters and to avoid collisions with any C<to_json>	510	usually in upper case letters and to avoid collisions with any C<to_json>
516	function or method.	511	function or method.
517		512
518	This setting does not yet influence C<decode> in any way, but in the	513	If C<$enable> is false (the default), then C<encode> will not consider
519	future, global hooks might get installed that influence C<decode> and are	514	this type of conversion.
520	enabled by this setting.
521		515
522	If C<$enable> is false, then the C<allow_blessed> setting will decide what	516	This setting has no effect on C<decode>.
523	to do when a blessed object is found.	517
		518	=item $json = $json->allow_tags ([$enable])
		519
		520	=item $enabled = $json->allow_tags
		521
		522	See L<OBJECT SERIALISATION> for details.
		523
		524	If C<$enable> is true (or missing), then C<encode>, upon encountering a
		525	blessed object, will check for the availability of the C<FREEZE> method on
		526	the object's class. If found, it will be used to serialise the object into
		527	a nonstandard tagged JSON value (that JSON decoders cannot decode).
		528
		529	It also causes C<decode> to parse such tagged JSON values and deserialise
		530	them via a call to the C<THAW> method.
		531
		532	If C<$enable> is false (the default), then C<encode> will not consider
		533	this type of conversion, and tagged JSON values will cause a parse error
		534	in C<decode>, as if tags were not part of the grammar.
524		535
525	=item $json = $json->filter_json_object ([$coderef->($hashref)])	536	=item $json = $json->filter_json_object ([$coderef->($hashref)])
526		537
527	When C<$coderef> is specified, it will be called from C<decode> each	538	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	539	time it decodes a JSON object. The only argument is a reference to the
…		…
667		678
668	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.	679	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
669		680
670	=item $json_text = $json->encode ($perl_scalar)	681	=item $json_text = $json->encode ($perl_scalar)
671		682
672	Converts the given Perl data structure (a simple scalar or a reference	683	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	684	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		685
679	=item $perl_scalar = $json->decode ($json_text)	686	=item $perl_scalar = $json->decode ($json_text)
680		687
681	The opposite of C<encode>: expects a JSON text and tries to parse it,	688	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.	689	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		690
688	=item ($perl_scalar, $characters) = $json->decode_prefix ($json_text)	691	=item ($perl_scalar, $characters) = $json->decode_prefix ($json_text)
689		692
690	This works like the C<decode> method, but instead of raising an exception	693	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	694	when there is trailing garbage after the first JSON object, it will
692	silently stop parsing there and return the number of characters consumed	695	silently stop parsing there and return the number of characters consumed
693	so far.	696	so far.
694		697
695	This is useful if your JSON texts are not delimited by an outer protocol	698	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.	699	and you need to know where the JSON text ends.
698		700
699	JSON::XS->new->decode_prefix ("[1] the tail")	701	JSON::XS->new->decode_prefix ("[1] the tail")
700	=> ([], 3)	702	=> ([], 3)
701		703
702	=back	704	=back
…		…
741		743
742	If the method is called in scalar context, then it will try to extract	744	If the method is called in scalar context, then it will try to extract
743	exactly I<one> JSON object. If that is successful, it will return this	745	exactly I<one> JSON object. If that is successful, it will return this
744	object, otherwise it will return C<undef>. If there is a parse error,	746	object, otherwise it will return C<undef>. If there is a parse error,
745	this method will croak just as C<decode> would do (one can then use	747	this method will croak just as C<decode> would do (one can then use
746	C<incr_skip> to skip the errornous part). This is the most common way of	748	C<incr_skip> to skip the erroneous part). This is the most common way of
747	using the method.	749	using the method.
748		750
749	And finally, in list context, it will try to extract as many objects	751	And finally, in list context, it will try to extract as many objects
750	from the stream as it can find and return them, or the empty list	752	from the stream as it can find and return them, or the empty list
751	otherwise. For this to work, there must be no separators between the JSON	753	otherwise. For this to work, there must be no separators between the JSON
…		…
780	C<incr_parse> died, in which case the input buffer and incremental parser	782	C<incr_parse> died, in which case the input buffer and incremental parser
781	state is left unchanged, to skip the text parsed so far and to reset the	783	state is left unchanged, to skip the text parsed so far and to reset the
782	parse state.	784	parse state.
783		785
784	The difference to C<incr_reset> is that only text until the parse error	786	The difference to C<incr_reset> is that only text until the parse error
785	occured is removed.	787	occurred is removed.
786		788
787	=item $json->incr_reset	789	=item $json->incr_reset
788		790
789	This completely resets the incremental parser, that is, after this call,	791	This completely resets the incremental parser, that is, after this call,
790	it will be as if the parser had never parsed anything.	792	it will be as if the parser had never parsed anything.
…		…
796	=back	798	=back
797		799
798	=head2 LIMITATIONS	800	=head2 LIMITATIONS
799		801
800	All options that affect decoding are supported, except	802	All options that affect decoding are supported, except
801	C<allow_nonref>. The reason for this is that it cannot be made to	803	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	804	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	805	concatenate them back to back and still decode them perfectly. This does
804	for JSON numbers, however.	806	not hold true for JSON numbers, however.
805		807
806	For example, is the string C<1> a single JSON number, or is it simply the	808	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	809	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	810	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.	811	takes the conservative route and disallows this case.
…		…
988	If the number consists of digits only, JSON::XS will try to represent	990	If the number consists of digits only, JSON::XS will try to represent
989	it as an integer value. If that fails, it will try to represent it as	991	it as an integer value. If that fails, it will try to represent it as
990	a numeric (floating point) value if that is possible without loss of	992	a numeric (floating point) value if that is possible without loss of
991	precision. Otherwise it will preserve the number as a string value (in	993	precision. Otherwise it will preserve the number as a string value (in
992	which case you lose roundtripping ability, as the JSON number will be	994	which case you lose roundtripping ability, as the JSON number will be
993	re-encoded toa JSON string).	995	re-encoded to a JSON string).
994		996
995	Numbers containing a fractional or exponential part will always be	997	Numbers containing a fractional or exponential part will always be
996	represented as numeric (floating point) values, possibly at a loss of	998	represented as numeric (floating point) values, possibly at a loss of
997	precision (in which case you might lose perfect roundtripping ability, but	999	precision (in which case you might lose perfect roundtripping ability, but
998	the JSON number will still be re-encoded as a JSON number).	1000	the JSON number will still be re-encoded as a JSON number).
999		1001
1000	Note that precision is not accuracy - binary floating point values cannot	1002	Note that precision is not accuracy - binary floating point values cannot
1001	represent most decimal fractions exactly, and when converting from and to	1003	represent most decimal fractions exactly, and when converting from and to
1002	floating point, JSON::XS only guarantees precision up to but not including	1004	floating point, JSON::XS only guarantees precision up to but not including
1003	the leats significant bit.	1005	the least significant bit.
1004		1006
1005	=item true, false	1007	=item true, false
1006		1008
1007	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,	1009	These JSON atoms become C<Types::Serialiser::true> and
1008	respectively. They are overloaded to act almost exactly like the numbers	1010	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	1011	almost exactly like the numbers C<1> and C<0>. You can check whether
1010	the C<JSON::XS::is_bool> function.	1012	a scalar is a JSON boolean by using the C<Types::Serialiser::is_bool>
		1013	function (after C<use Types::Serialier>, of course).
1011		1014
1012	=item null	1015	=item null
1013		1016
1014	A JSON null atom becomes C<undef> in Perl.	1017	A JSON null atom becomes C<undef> in Perl.
		1018
		1019	=item shell-style comments (C<< # I<text> >>)
		1020
		1021	As a nonstandard extension to the JSON syntax that is enabled by the
		1022	C<relaxed> setting, shell-style comments are allowed. They can start
		1023	anywhere outside strings and go till the end of the line.
		1024
		1025	=item tagged values (C<< (I<tag>)I<value> >>).
		1026
		1027	Another nonstandard extension to the JSON syntax, enabled with the
		1028	C<allow_tags> setting, are tagged values. In this implementation, the
		1029	I<tag> must be a perl package/class name encoded as a JSON string, and the
		1030	I<value> must be a JSON array encoding optional constructor arguments.
		1031
		1032	See L<OBJECT SERIALISATION>, below, for details.
1015		1033
1016	=back	1034	=back
1017		1035
1018		1036
1019	=head2 PERL -> JSON	1037	=head2 PERL -> JSON
…		…
1024		1042
1025	=over 4	1043	=over 4
1026		1044
1027	=item hash references	1045	=item hash references
1028		1046
1029	Perl hash references become JSON objects. As there is no inherent ordering	1047	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	1048	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	1049	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	1050	(determined by the I<canonical> flag), so the same datastructure will
1033	optionally sort the hash keys (determined by the I<canonical> flag), so	1051	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	1052	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	1053	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		1054
1039	=item array references	1055	=item array references
1040		1056
1041	Perl array references become JSON arrays.	1057	Perl array references become JSON arrays.
1042		1058
1043	=item other references	1059	=item other references
1044		1060
1045	Other unblessed references are generally not allowed and will cause an	1061	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	1062	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	1063	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		1064
		1065	Since C<JSON::XS> uses the boolean model from L<Types::Serialiser>, you
		1066	can also C<use Types::Serialiser> and then use C<Types::Serialiser::false>
		1067	and C<Types::Serialiser::true> to improve readability.
		1068
		1069	use Types::Serialiser;
1050	encode_json [\0, JSON::XS::true] # yields [false,true]	1070	encode_json [\0, Types::Serialiser::true] # yields [false,true]
1051		1071
1052	=item JSON::XS::true, JSON::XS::false	1072	=item Types::Serialiser::true, Types::Serialiser::false
1053		1073
1054	These special values become JSON true and JSON false values,	1074	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.	1075	and JSON false values, respectively. You can also use C<\1> and C<\0>
		1076	directly if you want.
1056		1077
1057	=item blessed objects	1078	=item blessed objects
1058		1079
1059	Blessed objects are not directly representable in JSON. See the	1080	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	1081	allows various ways of handling objects. See L<OBJECT SERIALISATION>,
1061	how to deal with this: basically, you can choose between throwing an	1082	below, for details.
1062	exception, encoding the reference as if it weren't blessed, or provide
1063	your own serialiser method.
1064		1083
1065	=item simple scalars	1084	=item simple scalars
1066		1085
1067	Simple Perl scalars (any scalar that is not a reference) are the most	1086	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	1087	difficult objects to encode: JSON::XS will encode undefined scalars as
…		…
1105	infinities or NaN's - these cannot be represented in JSON, and it is an	1124	infinities or NaN's - these cannot be represented in JSON, and it is an
1106	error to pass those in.	1125	error to pass those in.
1107		1126
1108	=back	1127	=back
1109		1128
		1129	=head2 OBJECT SERIALISATION
		1130
		1131	As JSON cannot directly represent Perl objects, you have to choose between
		1132	a pure JSON representation (without the ability to deserialise the object
		1133	automatically again), and a nonstandard extension to the JSON syntax,
		1134	tagged values.
		1135
		1136	=head3 SERIALISATION
		1137
		1138	What happens when C<JSON::XS> encounters a Perl object depends on the
		1139	C<allow_blessed>, C<convert_blessed> and C<allow_tags> settings, which are
		1140	used in this order:
		1141
		1142	=over 4
		1143
		1144	=item 1. C<allow_tags> is enabled and the object has a C<FREEZE> method.
		1145
		1146	In this case, C<JSON::XS> uses the L<Types::Serialiser> object
		1147	serialisation protocol to create a tagged JSON value, using a nonstandard
		1148	extension to the JSON syntax.
		1149
		1150	This works by invoking the C<FREEZE> method on the object, with the first
		1151	argument being the object to serialise, and the second argument being the
		1152	constant string C<JSON> to distinguish it from other serialisers.
		1153
		1154	The C<FREEZE> method can return any number of values (i.e. zero or
		1155	more). These values and the paclkage/classname of the object will then be
		1156	encoded as a tagged JSON value in the following format:
		1157
		1158	("classname")[FREEZE return values...]
		1159
		1160	e.g.:
		1161
		1162	("URI")["http://www.google.com/"]
		1163	("MyDate")[2013,10,29]
		1164	("ImageData::JPEG")["Z3...VlCg=="]
		1165
		1166	For example, the hypothetical C<My::Object> C<FREEZE> method might use the
		1167	objects C<type> and C<id> members to encode the object:
		1168
		1169	sub My::Object::FREEZE {
		1170	my ($self, $serialiser) = @_;
		1171
		1172	($self->{type}, $self->{id})
		1173	}
		1174
		1175	=item 2. C<convert_blessed> is enabled and the object has a C<TO_JSON> method.
		1176
		1177	In this case, the C<TO_JSON> method of the object is invoked in scalar
		1178	context. It must return a single scalar that can be directly encoded into
		1179	JSON. This scalar replaces the object in the JSON text.
		1180
		1181	For example, the following C<TO_JSON> method will convert all L<URI>
		1182	objects to JSON strings when serialised. The fatc that these values
		1183	originally were L<URI> objects is lost.
		1184
		1185	sub URI::TO_JSON {
		1186	my ($uri) = @_;
		1187	$uri->as_string
		1188	}
		1189
		1190	=item 3. C<allow_blessed> is enabled.
		1191
		1192	The object will be serialised as a JSON null value.
		1193
		1194	=item 4. none of the above
		1195
		1196	If none of the settings are enabled or the respective methods are missing,
		1197	C<JSON::XS> throws an exception.
		1198
		1199	=back
		1200
		1201	=head3 DESERIALISATION
		1202
		1203	For deserialisation there are only two cases to consider: either
		1204	nonstandard tagging was used, in which case C<allow_tags> decides,
		1205	or objects cannot be automatically be deserialised, in which
		1206	case you can use postprocessing or the C<filter_json_object> or
		1207	C<filter_json_single_key_object> callbacks to get some real objects our of
		1208	your JSON.
		1209
		1210	This section only considers the tagged value case: I a tagged JSON object
		1211	is encountered during decoding and C<allow_tags> is disabled, a parse
		1212	error will result (as if tagged values were not part of the grammar).
		1213
		1214	If C<allow_tags> is enabled, C<JSON::XS> will look up the C<THAW> method
		1215	of the package/classname used during serialisation (it will not attempt
		1216	to load the package as a Perl module). If there is no such method, the
		1217	decoding will fail with an error.
		1218
		1219	Otherwise, the C<THAW> method is invoked with the classname as first
		1220	argument, the constant string C<JSON> as second argument, and all the
		1221	values from the JSON array (the values originally returned by the
		1222	C<FREEZE> method) as remaining arguments.
		1223
		1224	The method must then return the object. While technically you can return
		1225	any Perl scalar, you might have to enable the C<enable_nonref> setting to
		1226	make that work in all cases, so better return an actual blessed reference.
		1227
		1228	As an example, let's implement a C<THAW> function that regenerates the
		1229	C<My::Object> from the C<FREEZE> example earlier:
		1230
		1231	sub My::Object::THAW {
		1232	my ($class, $serialiser, $type, $id) = @_;
		1233
		1234	$class->new (type => $type, id => $id)
		1235	}
		1236
1110		1237
1111	=head1 ENCODING/CODESET FLAG NOTES	1238	=head1 ENCODING/CODESET FLAG NOTES
1112		1239
1113	The interested reader might have seen a number of flags that signify	1240	The interested reader might have seen a number of flags that signify
1114	encodings or codesets - C<utf8>, C<latin1> and C<ascii>. There seems to be	1241	encodings or codesets - C<utf8>, C<latin1> and C<ascii>. There seems to be
…		…
1138	=item C<utf8> flag disabled	1265	=item C<utf8> flag disabled
1139		1266
1140	When C<utf8> is disabled (the default), then C<encode>/C<decode> generate	1267	When C<utf8> is disabled (the default), then C<encode>/C<decode> generate
1141	and expect Unicode strings, that is, characters with high ordinal Unicode	1268	and expect Unicode strings, that is, characters with high ordinal Unicode
1142	values (> 255) will be encoded as such characters, and likewise such	1269	values (> 255) will be encoded as such characters, and likewise such
1143	characters are decoded as-is, no canges to them will be done, except	1270	characters are decoded as-is, no changes to them will be done, except
1144	"(re-)interpreting" them as Unicode codepoints or Unicode characters,	1271	"(re-)interpreting" them as Unicode codepoints or Unicode characters,
1145	respectively (to Perl, these are the same thing in strings unless you do	1272	respectively (to Perl, these are the same thing in strings unless you do
1146	funny/weird/dumb stuff).	1273	funny/weird/dumb stuff).
1147		1274
1148	This is useful when you want to do the encoding yourself (e.g. when you	1275	This is useful when you want to do the encoding yourself (e.g. when you
…		…
1264	output for these property strings, e.g.:	1391	output for these property strings, e.g.:
1265		1392
1266	$json =~ s/"__proto__"\s*:/"__proto__renamed":/g;	1393	$json =~ s/"__proto__"\s*:/"__proto__renamed":/g;
1267		1394
1268	This works because C<__proto__> is not valid outside of strings, so every	1395	This works because C<__proto__> is not valid outside of strings, so every
1269	occurence of C<"__proto__"\s*:> must be a string used as property name.	1396	occurrence of C<"__proto__"\s*:> must be a string used as property name.
1270		1397
1271	If you know of other incompatibilities, please let me know.	1398	If you know of other incompatibilities, please let me know.
1272		1399
1273		1400
1274	=head2 JSON and YAML	1401	=head2 JSON and YAML
…		…
1436	are browser design bugs, but it is still you who will have to deal with	1563	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	1564	it, as major browser developers care only for features, not about getting
1438	security right).	1565	security right).
1439		1566
1440		1567
		1568	=head1 INTEROPERABILITY WITH OTHER MODULES
		1569
		1570	C<JSON::XS> uses the L<Types::Serialiser> module to provide boolean
		1571	constants. That means that the JSON true and false values will be
		1572	comaptible to true and false values of iother modules that do the same,
		1573	such as L<JSON::PP> and L<CBOR::XS>.
		1574
		1575
		1576	=head1 INTEROPERABILITY WITH OTHER JSON DECODERS
		1577
		1578	As long as you only serialise data that can be directly expressed in JSON,
		1579	C<JSON::XS> is incapable of generating invalid JSON output (modulo bugs,
		1580	but C<JSON::XS> has found more bugs in the official JSON testsuite (1)
		1581	than the official JSON testsuite has found in C<JSON::XS> (0)).
		1582
		1583	When you have trouble decoding JSON generated by this module using other
		1584	decoders, then it is very likely that you have an encoding mismatch or the
		1585	other decoder is broken.
		1586
		1587	When decoding, C<JSON::XS> is strict by default and will likely catch all
		1588	errors. There are currently two settings that change this: C<relaxed>
		1589	makes C<JSON::XS> accept (but not generate) some non-standard extensions,
		1590	and C<allow_tags> will allow you to encode and decode Perl objects, at the
		1591	cost of not outputting valid JSON anymore.
		1592
		1593	=head2 TAGGED VALUE SYNTAX AND STANDARD JSON EN/DECODERS
		1594
		1595	When you use C<allow_tags> to use the extended (and also nonstandard and
		1596	invalid) JSON syntax for serialised objects, and you still want to decode
		1597	the generated When you want to serialise objects, you can run a regex
		1598	to replace the tagged syntax by standard JSON arrays (it only works for
		1599	"normal" packagesnames without comma, newlines or single colons). First,
		1600	the readable Perl version:
		1601
		1602	# if your FREEZE methods return no values, you need this replace first:
		1603	$json =~ s/$ \s* (" (?: [^\\":,]+\|\\.\|::)* ") \s* $ \s* \[\s*\]/[$1]/gx;
		1604
		1605	# this works for non-empty constructor arg lists:
		1606	$json =~ s/$ \s* (" (?: [^\\":,]+\|\\.\|::)* ") \s* $ \s* \[/[$1,/gx;
		1607
		1608	And here is a less readable version that is easy to adapt to other
		1609	languages:
		1610
		1611	$json =~ s/$\s("([^\\":,]+\|\\.\|::)")\s$\s\[/[$1,/g;
		1612
		1613	Here is an ECMAScript version (same regex):
		1614
		1615	json = json.replace (/$\s("([^\\":,]+\|\\.\|::)")\s$\s\[/g, "[$1,");
		1616
		1617	Since this syntax converts to standard JSON arrays, it might be hard to
		1618	distinguish serialised objects from normal arrays. You can prepend a
		1619	"magic number" as first array element to reduce chances of a collision:
		1620
		1621	$json =~ s/$\s("([^\\":,]+\|\\.\|::)")\s$\s\[/["XU1peReLzT4ggEllLanBYq4G9VzliwKF",$1,/g;
		1622
		1623	And after decoding the JSON text, you could walk the data
		1624	structure looking for arrays with a first element of
		1625	C<XU1peReLzT4ggEllLanBYq4G9VzliwKF>.
		1626
		1627	The same approach can be used to create the tagged format with another
		1628	encoder. First, you create an array with the magic string as first member,
		1629	the classname as second, and constructor arguments last, encode it as part
		1630	of your JSON structure, and then:
		1631
		1632	$json =~ s/\[\s"XU1peReLzT4ggEllLanBYq4G9VzliwKF"\s,\s("([^\\":,]+\|\\.\|::)")\s*,/($1)[/g;
		1633
		1634	Again, this has some limitations - the magic string must not be encoded
		1635	with character escapes, and the constructor arguments must be non-empty.
		1636
		1637
		1638	=head1 RFC7159
		1639
		1640	Since this module was written, Google has written a new JSON RFC, RFC 7159
		1641	(and RFC7158). Unfortunately, this RFC breaks compatibility with both the
		1642	original JSON specification on www.json.org and RFC4627.
		1643
		1644	As far as I can see, you can get partial compatibility when parsing by
		1645	using C<< ->allow_nonref >>. However, consider thew security implications
		1646	of doing so.
		1647
		1648	I haven't decided yet when to break compatibility with RFC4627 by default
		1649	(and potentially leave applications insecure) and change the default to
		1650	follow RFC7159, but application authors are well advised to call C<<
		1651	->allow_nonref(0) >> even if this is the current default, if they cannot
		1652	handle non-reference values, in preparation for the day when the4 default
		1653	will change.
		1654
		1655
1441	=head1 THREADS	1656	=head1 THREADS
1442		1657
1443	This module is I<not> guaranteed to be thread safe and there are no	1658	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	1659	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	1660	horribly slow so-called "threads" which are simply slow and bloated
…		…
1452		1667
1453	Sometimes people avoid the Perl locale support and directly call the	1668	Sometimes people avoid the Perl locale support and directly call the
1454	system's setlocale function with C<LC_ALL>.	1669	system's setlocale function with C<LC_ALL>.
1455		1670
1456	This breaks both perl and modules such as JSON::XS, as stringification of	1671	This breaks both perl and modules such as JSON::XS, as stringification of
1457	numbers no longer works correcly (e.g. C<$x = 0.1; print "$x"+1> might	1672	numbers no longer works correctly (e.g. C<$x = 0.1; print "$x"+1> might
1458	print C<1>, and JSON::XS might output illegal JSON as JSON::XS relies on	1673	print C<1>, and JSON::XS might output illegal JSON as JSON::XS relies on
1459	perl to stringify numbers).	1674	perl to stringify numbers).
1460		1675
1461	The solution is simple: don't call C<setlocale>, or use it for only those	1676	The solution is simple: don't call C<setlocale>, or use it for only those
1462	categories you need, such as C<LC_MESSAGES> or C<LC_CTYPE>.	1677	categories you need, such as C<LC_MESSAGES> or C<LC_CTYPE>.
…		…
1475	Please refrain from using rt.cpan.org or any other bug reporting	1690	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.	1691	service. I put the contact address into my modules for a reason.
1477		1692
1478	=cut	1693	=cut
1479		1694
1480	our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" };	1695	BEGIN {
1481	our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" };	1696	*true = \$Types::Serialiser::true;
		1697	*true = \&Types::Serialiser::true;
		1698	*false = \$Types::Serialiser::false;
		1699	*false = \&Types::Serialiser::false;
		1700	*is_bool = \&Types::Serialiser::is_bool;
1482		1701
1483	sub true() { $true }	1702	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	}	1703	}
1490		1704
1491	XSLoader::load "JSON::XS", $VERSION;	1705	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		1706
1503	=head1 SEE ALSO	1707	=head1 SEE ALSO
1504		1708
1505	The F<json_xs> command line utility for quick experiments.	1709	The F<json_xs> command line utility for quick experiments.
1506		1710
…		…
1509	Marc Lehmann <schmorp@schmorp.de>	1713	Marc Lehmann <schmorp@schmorp.de>
1510	http://home.schmorp.de/	1714	http://home.schmorp.de/
1511		1715
1512	=cut	1716	=cut
1513		1717
		1718	1
		1719

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Comparing JSON-XS/XS.pm (file contents): Revision 1.139 by root, Thu May 23 09:31:32 2013 UTC vs. Revision 1.155 by root, Mon Nov 24 18:42:51 2014 UTC

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Revision 1.139 by root, Thu May 23 09:31:32 2013 UTC vs.
Revision 1.155 by root, Mon Nov 24 18:42:51 2014 UTC