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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.121 by root, Mon Jul 13 22:13:17 2009 UTC vs.
Revision 1.160 by root, Wed Nov 16 18:08:30 2016 UTC

…		…
64	so, and even documents what "correct" means.	64	so, and even documents what "correct" means.
65		65
66	=item * round-trip integrity	66	=item * round-trip integrity
67		67
68	When you serialise a perl data structure using only data types supported	68	When you serialise a perl data structure using only data types supported
69	by JSON, the deserialised data structure is identical on the Perl level.	69	by JSON and Perl, the deserialised data structure is identical on the Perl
70	(e.g. the string "2.0" doesn't suddenly become "2" just because it looks	70	level. (e.g. the string "2.0" doesn't suddenly become "2" just because
71	like a number). There minor I<are> exceptions to this, read the MAPPING	71	it looks like a number). There I<are> minor exceptions to this, read the
72	section below to learn about those.	72	MAPPING section below to learn about those.
73		73
74	=item * strict checking of JSON correctness	74	=item * strict checking of JSON correctness
75		75
76	There is no guessing, no generating of illegal JSON texts by default,	76	There is no guessing, no generating of illegal JSON texts by default,
77	and only JSON is accepted as input by default (the latter is a security	77	and only JSON is accepted as input by default (the latter is a security
…		…
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 = '2.24';	106	our $VERSION = 3.02;
107	our @ISA = qw(Exporter);	107	our @ISA = qw(Exporter);
108		108
109	our @EXPORT = qw(encode_json decode_json to_json from_json);	109	our @EXPORT = qw(encode_json decode_json);
110
111	sub to_json($) {
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 = $json->get_canonical
…		…
432	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects	425	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects
433	by sorting their keys. This is adding a comparatively high overhead.	426	by sorting their keys. This is adding a comparatively high overhead.
434		427
435	If C<$enable> is false, then the C<encode> method will output key-value	428	If C<$enable> is false, then the C<encode> method will output key-value
436	pairs in the order Perl stores them (which will likely change between runs	429	pairs in the order Perl stores them (which will likely change between runs
437	of the same script).	430	of the same script, and can change even within the same run from 5.18
		431	onwards).
438		432
439	This option is useful if you want the same data structure to be encoded as	433	This option is useful if you want the same data structure to be encoded as
440	the same JSON text (given the same overall settings). If it is disabled,	434	the same JSON text (given the same overall settings). If it is disabled,
441	the same hash might be encoded differently even if contains the same data,	435	the same hash might be encoded differently even if contains the same data,
442	as key-value pairs have no inherent ordering in Perl.	436	as key-value pairs have no inherent ordering in Perl.
443		437
444	This setting has no effect when decoding JSON texts.	438	This setting has no effect when decoding JSON texts.
		439
		440	This setting has currently no effect on tied hashes.
445		441
446	=item $json = $json->allow_nonref ([$enable])	442	=item $json = $json->allow_nonref ([$enable])
447		443
448	=item $enabled = $json->get_allow_nonref	444	=item $enabled = $json->get_allow_nonref
449		445
…		…
481		477
482	=item $json = $json->allow_blessed ([$enable])	478	=item $json = $json->allow_blessed ([$enable])
483		479
484	=item $enabled = $json->get_allow_blessed	480	=item $enabled = $json->get_allow_blessed
485		481
		482	See L<OBJECT SERIALISATION> for details.
		483
486	If C<$enable> is true (or missing), then the C<encode> method will not	484	If C<$enable> is true (or missing), then the C<encode> method will not
487	barf when it encounters a blessed reference. Instead, the value of the	485	barf when it encounters a blessed reference that it cannot convert
488	B<convert_blessed> option will decide whether C<null> (C<convert_blessed>	486	otherwise. Instead, a JSON C<null> value is encoded instead of the object.
489	disabled or no C<TO_JSON> method found) or a representation of the
490	object (C<convert_blessed> enabled and C<TO_JSON> method found) is being
491	encoded. Has no effect on C<decode>.
492		487
493	If C<$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
494	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>.
495		493
496	=item $json = $json->convert_blessed ([$enable])	494	=item $json = $json->convert_blessed ([$enable])
497		495
498	=item $enabled = $json->get_convert_blessed	496	=item $enabled = $json->get_convert_blessed
		497
		498	See L<OBJECT SERIALISATION> for details.
499		499
500	If C<$enable> is true (or missing), then C<encode>, upon encountering a	500	If C<$enable> is true (or missing), then C<encode>, upon encountering a
501	blessed object, will check for the availability of the C<TO_JSON> method	501	blessed object, will check for the availability of the C<TO_JSON> method
502	on the object's class. If found, it will be called in scalar context	502	on the object's class. If found, it will be called in scalar context and
503	and the resulting scalar will be encoded instead of the object. If no	503	the resulting scalar will be encoded instead of the object.
504	C<TO_JSON> method is found, the value of C<allow_blessed> will decide what
505	to do.
506		504
507	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>	505	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>
508	returns other blessed objects, those will be handled in the same	506	returns other blessed objects, those will be handled in the same
509	way. C<TO_JSON> must take care of not causing an endless recursion cycle	507	way. C<TO_JSON> must take care of not causing an endless recursion cycle
510	(== crash) in this case. The name of C<TO_JSON> was chosen because other	508	(== crash) in this case. The name of C<TO_JSON> was chosen because other
511	methods called by the Perl core (== not by the user of the object) are	509	methods called by the Perl core (== not by the user of the object) are
512	usually in upper case letters and to avoid collisions with any C<to_json>	510	usually in upper case letters and to avoid collisions with any C<to_json>
513	function or method.	511	function or method.
514		512
515	This setting does not yet influence C<decode> in any way, but in the	513	If C<$enable> is false (the default), then C<encode> will not consider
516	future, global hooks might get installed that influence C<decode> and are	514	this type of conversion.
517	enabled by this setting.
518		515
519	If C<$enable> is false, then the C<allow_blessed> setting will decide what	516	This setting has no effect on C<decode>.
520	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.
521		535
522	=item $json = $json->filter_json_object ([$coderef->($hashref)])	536	=item $json = $json->filter_json_object ([$coderef->($hashref)])
523		537
524	When C<$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
525	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
…		…
664		678
665	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.
666		680
667	=item $json_text = $json->encode ($perl_scalar)	681	=item $json_text = $json->encode ($perl_scalar)
668		682
669	Converts the given Perl data structure (a simple scalar or a reference	683	Converts the given Perl value or data structure to its JSON
670	to a hash or array) to its JSON representation. Simple scalars will be	684	representation. Croaks on error.
671	converted into JSON string or number sequences, while references to arrays
672	become JSON arrays and references to hashes become JSON objects. Undefined
673	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>
674	nor C<false> values will be generated.
675		685
676	=item $perl_scalar = $json->decode ($json_text)	686	=item $perl_scalar = $json->decode ($json_text)
677		687
678	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,
679	returning the resulting simple scalar or reference. Croaks on error.	689	returning the resulting simple scalar or reference. Croaks on error.
680
681	JSON numbers and strings become simple Perl scalars. JSON arrays become
682	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes
683	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.
684		690
685	=item ($perl_scalar, $characters) = $json->decode_prefix ($json_text)	691	=item ($perl_scalar, $characters) = $json->decode_prefix ($json_text)
686		692
687	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
688	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
689	silently stop parsing there and return the number of characters consumed	695	silently stop parsing there and return the number of characters consumed
690	so far.	696	so far.
691		697
692	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
693	(which is not the brightest thing to do in the first place) and you need
694	to know where the JSON text ends.	699	and you need to know where the JSON text ends.
695		700
696	JSON::XS->new->decode_prefix ("[1] the tail")	701	JSON::XS->new->decode_prefix ("[1] the tail")
697	=> ([], 3)	702	=> ([1], 3)
698		703
699	=back	704	=back
700		705
701		706
702	=head1 INCREMENTAL PARSING	707	=head1 INCREMENTAL PARSING
…		…
711	calls).	716	calls).
712		717
713	JSON::XS will only attempt to parse the JSON text once it is sure it	718	JSON::XS will only attempt to parse the JSON text once it is sure it
714	has enough text to get a decisive result, using a very simple but	719	has enough text to get a decisive result, using a very simple but
715	truly incremental parser. This means that it sometimes won't stop as	720	truly incremental parser. This means that it sometimes won't stop as
716	early as the full parser, for example, it doesn't detect parenthese	721	early as the full parser, for example, it doesn't detect mismatched
717	mismatches. The only thing it guarantees is that it starts decoding as	722	parentheses. The only thing it guarantees is that it starts decoding as
718	soon as a syntactically valid JSON text has been seen. This means you need	723	soon as a syntactically valid JSON text has been seen. This means you need
719	to set resource limits (e.g. C<max_size>) to ensure the parser will stop	724	to set resource limits (e.g. C<max_size>) to ensure the parser will stop
720	parsing in the presence if syntax errors.	725	parsing in the presence if syntax errors.
721		726
722	The following methods implement this incremental parser.	727	The following methods implement this incremental parser.
…		…
738		743
739	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
740	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
741	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,
742	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
743	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
744	using the method.	749	using the method.
745		750
746	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
747	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
748	otherwise. For this to work, there must be no separators between the JSON	753	otherwise. For this to work, there must be no separators (other than
749	objects or arrays, instead they must be concatenated back-to-back. If	754	whitespace) between the JSON objects or arrays, instead they must be
750	an error occurs, an exception will be raised as in the scalar context	755	concatenated back-to-back. If an error occurs, an exception will be
751	case. Note that in this case, any previously-parsed JSON texts will be	756	raised as in the scalar context case. Note that in this case, any
752	lost.	757	previously-parsed JSON texts will be lost.
		758
		759	Example: Parse some JSON arrays/objects in a given string and return
		760	them.
		761
		762	my @objs = JSON::XS->new->incr_parse ("[5][7][1,2]");
753		763
754	=item $lvalue_string = $json->incr_text	764	=item $lvalue_string = $json->incr_text
755		765
756	This method returns the currently stored JSON fragment as an lvalue, that	766	This method returns the currently stored JSON fragment as an lvalue, that
757	is, you can manipulate it. This I<only> works when a preceding call to	767	is, you can manipulate it. This I<only> works when a preceding call to
…		…
759	all other circumstances you must not call this function (I mean it.	769	all other circumstances you must not call this function (I mean it.
760	although in simple tests it might actually work, it I<will> fail under	770	although in simple tests it might actually work, it I<will> fail under
761	real world conditions). As a special exception, you can also call this	771	real world conditions). As a special exception, you can also call this
762	method before having parsed anything.	772	method before having parsed anything.
763		773
		774	That means you can only use this function to look at or manipulate text
		775	before or after complete JSON objects, not while the parser is in the
		776	middle of parsing a JSON object.
		777
764	This function is useful in two cases: a) finding the trailing text after a	778	This function is useful in two cases: a) finding the trailing text after a
765	JSON object or b) parsing multiple JSON objects separated by non-JSON text	779	JSON object or b) parsing multiple JSON objects separated by non-JSON text
766	(such as commas).	780	(such as commas).
767		781
768	=item $json->incr_skip	782	=item $json->incr_skip
…		…
772	C<incr_parse> died, in which case the input buffer and incremental parser	786	C<incr_parse> died, in which case the input buffer and incremental parser
773	state is left unchanged, to skip the text parsed so far and to reset the	787	state is left unchanged, to skip the text parsed so far and to reset the
774	parse state.	788	parse state.
775		789
776	The difference to C<incr_reset> is that only text until the parse error	790	The difference to C<incr_reset> is that only text until the parse error
777	occured is removed.	791	occurred is removed.
778		792
779	=item $json->incr_reset	793	=item $json->incr_reset
780		794
781	This completely resets the incremental parser, that is, after this call,	795	This completely resets the incremental parser, that is, after this call,
782	it will be as if the parser had never parsed anything.	796	it will be as if the parser had never parsed anything.
…		…
788	=back	802	=back
789		803
790	=head2 LIMITATIONS	804	=head2 LIMITATIONS
791		805
792	All options that affect decoding are supported, except	806	All options that affect decoding are supported, except
793	C<allow_nonref>. The reason for this is that it cannot be made to	807	C<allow_nonref>. The reason for this is that it cannot be made to work
794	work sensibly: JSON objects and arrays are self-delimited, i.e. you can concatenate	808	sensibly: JSON objects and arrays are self-delimited, i.e. you can
795	them back to back and still decode them perfectly. This does not hold true	809	concatenate them back to back and still decode them perfectly. This does
796	for JSON numbers, however.	810	not hold true for JSON numbers, however.
797		811
798	For example, is the string C<1> a single JSON number, or is it simply the	812	For example, is the string C<1> a single JSON number, or is it simply the
799	start of C<12>? Or is C<12> a single JSON number, or the concatenation	813	start of C<12>? Or is C<12> a single JSON number, or the concatenation
800	of C<1> and C<2>? In neither case you can tell, and this is why JSON::XS	814	of C<1> and C<2>? In neither case you can tell, and this is why JSON::XS
801	takes the conservative route and disallows this case.	815	takes the conservative route and disallows this case.
…		…
980	If the number consists of digits only, JSON::XS will try to represent	994	If the number consists of digits only, JSON::XS will try to represent
981	it as an integer value. If that fails, it will try to represent it as	995	it as an integer value. If that fails, it will try to represent it as
982	a numeric (floating point) value if that is possible without loss of	996	a numeric (floating point) value if that is possible without loss of
983	precision. Otherwise it will preserve the number as a string value (in	997	precision. Otherwise it will preserve the number as a string value (in
984	which case you lose roundtripping ability, as the JSON number will be	998	which case you lose roundtripping ability, as the JSON number will be
985	re-encoded toa JSON string).	999	re-encoded to a JSON string).
986		1000
987	Numbers containing a fractional or exponential part will always be	1001	Numbers containing a fractional or exponential part will always be
988	represented as numeric (floating point) values, possibly at a loss of	1002	represented as numeric (floating point) values, possibly at a loss of
989	precision (in which case you might lose perfect roundtripping ability, but	1003	precision (in which case you might lose perfect roundtripping ability, but
990	the JSON number will still be re-encoded as a JSON number).	1004	the JSON number will still be re-encoded as a JSON number).
991		1005
		1006	Note that precision is not accuracy - binary floating point values cannot
		1007	represent most decimal fractions exactly, and when converting from and to
		1008	floating point, JSON::XS only guarantees precision up to but not including
		1009	the least significant bit.
		1010
992	=item true, false	1011	=item true, false
993		1012
994	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,	1013	These JSON atoms become C<Types::Serialiser::true> and
995	respectively. They are overloaded to act almost exactly like the numbers	1014	C<Types::Serialiser::false>, respectively. They are overloaded to act
996	C<1> and C<0>. You can check whether a scalar is a JSON boolean by using	1015	almost exactly like the numbers C<1> and C<0>. You can check whether
997	the C<JSON::XS::is_bool> function.	1016	a scalar is a JSON boolean by using the C<Types::Serialiser::is_bool>
		1017	function (after C<use Types::Serialier>, of course).
998		1018
999	=item null	1019	=item null
1000		1020
1001	A JSON null atom becomes C<undef> in Perl.	1021	A JSON null atom becomes C<undef> in Perl.
		1022
		1023	=item shell-style comments (C<< # I<text> >>)
		1024
		1025	As a nonstandard extension to the JSON syntax that is enabled by the
		1026	C<relaxed> setting, shell-style comments are allowed. They can start
		1027	anywhere outside strings and go till the end of the line.
		1028
		1029	=item tagged values (C<< (I<tag>)I<value> >>).
		1030
		1031	Another nonstandard extension to the JSON syntax, enabled with the
		1032	C<allow_tags> setting, are tagged values. In this implementation, the
		1033	I<tag> must be a perl package/class name encoded as a JSON string, and the
		1034	I<value> must be a JSON array encoding optional constructor arguments.
		1035
		1036	See L<OBJECT SERIALISATION>, below, for details.
1002		1037
1003	=back	1038	=back
1004		1039
1005		1040
1006	=head2 PERL -> JSON	1041	=head2 PERL -> JSON
…		…
1011		1046
1012	=over 4	1047	=over 4
1013		1048
1014	=item hash references	1049	=item hash references
1015		1050
1016	Perl hash references become JSON objects. As there is no inherent ordering	1051	Perl hash references become JSON objects. As there is no inherent
1017	in hash keys (or JSON objects), they will usually be encoded in a	1052	ordering in hash keys (or JSON objects), they will usually be encoded
1018	pseudo-random order that can change between runs of the same program but	1053	in a pseudo-random order. JSON::XS can optionally sort the hash keys
1019	stays generally the same within a single run of a program. JSON::XS can	1054	(determined by the I<canonical> flag), so the same datastructure will
1020	optionally sort the hash keys (determined by the I<canonical> flag), so	1055	serialise to the same JSON text (given same settings and version of
1021	the same datastructure will serialise to the same JSON text (given same	1056	JSON::XS), but this incurs a runtime overhead and is only rarely useful,
1022	settings and version of JSON::XS), but this incurs a runtime overhead	1057	e.g. when you want to compare some JSON text against another for equality.
1023	and is only rarely useful, e.g. when you want to compare some JSON text
1024	against another for equality.
1025		1058
1026	=item array references	1059	=item array references
1027		1060
1028	Perl array references become JSON arrays.	1061	Perl array references become JSON arrays.
1029		1062
1030	=item other references	1063	=item other references
1031		1064
1032	Other unblessed references are generally not allowed and will cause an	1065	Other unblessed references are generally not allowed and will cause an
1033	exception to be thrown, except for references to the integers C<0> and	1066	exception to be thrown, except for references to the integers C<0> and
1034	C<1>, which get turned into C<false> and C<true> atoms in JSON. You can	1067	C<1>, which get turned into C<false> and C<true> atoms in JSON.
1035	also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability.
1036		1068
		1069	Since C<JSON::XS> uses the boolean model from L<Types::Serialiser>, you
		1070	can also C<use Types::Serialiser> and then use C<Types::Serialiser::false>
		1071	and C<Types::Serialiser::true> to improve readability.
		1072
		1073	use Types::Serialiser;
1037	encode_json [\0, JSON::XS::true] # yields [false,true]	1074	encode_json [\0, Types::Serialiser::true] # yields [false,true]
1038		1075
1039	=item JSON::XS::true, JSON::XS::false	1076	=item Types::Serialiser::true, Types::Serialiser::false
1040		1077
1041	These special values become JSON true and JSON false values,	1078	These special values from the L<Types::Serialiser> module become JSON true
1042	respectively. You can also use C<\1> and C<\0> directly if you want.	1079	and JSON false values, respectively. You can also use C<\1> and C<\0>
		1080	directly if you want.
1043		1081
1044	=item blessed objects	1082	=item blessed objects
1045		1083
1046	Blessed objects are not directly representable in JSON. See the	1084	Blessed objects are not directly representable in JSON, but C<JSON::XS>
1047	C<allow_blessed> and C<convert_blessed> methods on various options on	1085	allows various ways of handling objects. See L<OBJECT SERIALISATION>,
1048	how to deal with this: basically, you can choose between throwing an	1086	below, for details.
1049	exception, encoding the reference as if it weren't blessed, or provide
1050	your own serialiser method.
1051		1087
1052	=item simple scalars	1088	=item simple scalars
1053		1089
1054	Simple Perl scalars (any scalar that is not a reference) are the most	1090	Simple Perl scalars (any scalar that is not a reference) are the most
1055	difficult objects to encode: JSON::XS will encode undefined scalars as	1091	difficult objects to encode: JSON::XS will encode undefined scalars as
…		…
1083		1119
1084	You can not currently force the type in other, less obscure, ways. Tell me	1120	You can not currently force the type in other, less obscure, ways. Tell me
1085	if you need this capability (but don't forget to explain why it's needed	1121	if you need this capability (but don't forget to explain why it's needed
1086	:).	1122	:).
1087		1123
		1124	Note that numerical precision has the same meaning as under Perl (so
		1125	binary to decimal conversion follows the same rules as in Perl, which
		1126	can differ to other languages). Also, your perl interpreter might expose
		1127	extensions to the floating point numbers of your platform, such as
		1128	infinities or NaN's - these cannot be represented in JSON, and it is an
		1129	error to pass those in.
		1130
1088	=back	1131	=back
		1132
		1133	=head2 OBJECT SERIALISATION
		1134
		1135	As JSON cannot directly represent Perl objects, you have to choose between
		1136	a pure JSON representation (without the ability to deserialise the object
		1137	automatically again), and a nonstandard extension to the JSON syntax,
		1138	tagged values.
		1139
		1140	=head3 SERIALISATION
		1141
		1142	What happens when C<JSON::XS> encounters a Perl object depends on the
		1143	C<allow_blessed>, C<convert_blessed> and C<allow_tags> settings, which are
		1144	used in this order:
		1145
		1146	=over 4
		1147
		1148	=item 1. C<allow_tags> is enabled and the object has a C<FREEZE> method.
		1149
		1150	In this case, C<JSON::XS> uses the L<Types::Serialiser> object
		1151	serialisation protocol to create a tagged JSON value, using a nonstandard
		1152	extension to the JSON syntax.
		1153
		1154	This works by invoking the C<FREEZE> method on the object, with the first
		1155	argument being the object to serialise, and the second argument being the
		1156	constant string C<JSON> to distinguish it from other serialisers.
		1157
		1158	The C<FREEZE> method can return any number of values (i.e. zero or
		1159	more). These values and the paclkage/classname of the object will then be
		1160	encoded as a tagged JSON value in the following format:
		1161
		1162	("classname")[FREEZE return values...]
		1163
		1164	e.g.:
		1165
		1166	("URI")["http://www.google.com/"]
		1167	("MyDate")[2013,10,29]
		1168	("ImageData::JPEG")["Z3...VlCg=="]
		1169
		1170	For example, the hypothetical C<My::Object> C<FREEZE> method might use the
		1171	objects C<type> and C<id> members to encode the object:
		1172
		1173	sub My::Object::FREEZE {
		1174	my ($self, $serialiser) = @_;
		1175
		1176	($self->{type}, $self->{id})
		1177	}
		1178
		1179	=item 2. C<convert_blessed> is enabled and the object has a C<TO_JSON> method.
		1180
		1181	In this case, the C<TO_JSON> method of the object is invoked in scalar
		1182	context. It must return a single scalar that can be directly encoded into
		1183	JSON. This scalar replaces the object in the JSON text.
		1184
		1185	For example, the following C<TO_JSON> method will convert all L<URI>
		1186	objects to JSON strings when serialised. The fatc that these values
		1187	originally were L<URI> objects is lost.
		1188
		1189	sub URI::TO_JSON {
		1190	my ($uri) = @_;
		1191	$uri->as_string
		1192	}
		1193
		1194	=item 3. C<allow_blessed> is enabled.
		1195
		1196	The object will be serialised as a JSON null value.
		1197
		1198	=item 4. none of the above
		1199
		1200	If none of the settings are enabled or the respective methods are missing,
		1201	C<JSON::XS> throws an exception.
		1202
		1203	=back
		1204
		1205	=head3 DESERIALISATION
		1206
		1207	For deserialisation there are only two cases to consider: either
		1208	nonstandard tagging was used, in which case C<allow_tags> decides,
		1209	or objects cannot be automatically be deserialised, in which
		1210	case you can use postprocessing or the C<filter_json_object> or
		1211	C<filter_json_single_key_object> callbacks to get some real objects our of
		1212	your JSON.
		1213
		1214	This section only considers the tagged value case: I a tagged JSON object
		1215	is encountered during decoding and C<allow_tags> is disabled, a parse
		1216	error will result (as if tagged values were not part of the grammar).
		1217
		1218	If C<allow_tags> is enabled, C<JSON::XS> will look up the C<THAW> method
		1219	of the package/classname used during serialisation (it will not attempt
		1220	to load the package as a Perl module). If there is no such method, the
		1221	decoding will fail with an error.
		1222
		1223	Otherwise, the C<THAW> method is invoked with the classname as first
		1224	argument, the constant string C<JSON> as second argument, and all the
		1225	values from the JSON array (the values originally returned by the
		1226	C<FREEZE> method) as remaining arguments.
		1227
		1228	The method must then return the object. While technically you can return
		1229	any Perl scalar, you might have to enable the C<enable_nonref> setting to
		1230	make that work in all cases, so better return an actual blessed reference.
		1231
		1232	As an example, let's implement a C<THAW> function that regenerates the
		1233	C<My::Object> from the C<FREEZE> example earlier:
		1234
		1235	sub My::Object::THAW {
		1236	my ($class, $serialiser, $type, $id) = @_;
		1237
		1238	$class->new (type => $type, id => $id)
		1239	}
1089		1240
1090		1241
1091	=head1 ENCODING/CODESET FLAG NOTES	1242	=head1 ENCODING/CODESET FLAG NOTES
1092		1243
1093	The interested reader might have seen a number of flags that signify	1244	The interested reader might have seen a number of flags that signify
…		…
1118	=item C<utf8> flag disabled	1269	=item C<utf8> flag disabled
1119		1270
1120	When C<utf8> is disabled (the default), then C<encode>/C<decode> generate	1271	When C<utf8> is disabled (the default), then C<encode>/C<decode> generate
1121	and expect Unicode strings, that is, characters with high ordinal Unicode	1272	and expect Unicode strings, that is, characters with high ordinal Unicode
1122	values (> 255) will be encoded as such characters, and likewise such	1273	values (> 255) will be encoded as such characters, and likewise such
1123	characters are decoded as-is, no canges to them will be done, except	1274	characters are decoded as-is, no changes to them will be done, except
1124	"(re-)interpreting" them as Unicode codepoints or Unicode characters,	1275	"(re-)interpreting" them as Unicode codepoints or Unicode characters,
1125	respectively (to Perl, these are the same thing in strings unless you do	1276	respectively (to Perl, these are the same thing in strings unless you do
1126	funny/weird/dumb stuff).	1277	funny/weird/dumb stuff).
1127		1278
1128	This is useful when you want to do the encoding yourself (e.g. when you	1279	This is useful when you want to do the encoding yourself (e.g. when you
…		…
1236	well - using C<eval> naively simply I<will> cause problems.	1387	well - using C<eval> naively simply I<will> cause problems.
1237		1388
1238	Another problem is that some javascript implementations reserve	1389	Another problem is that some javascript implementations reserve
1239	some property names for their own purposes (which probably makes	1390	some property names for their own purposes (which probably makes
1240	them non-ECMAscript-compliant). For example, Iceweasel reserves the	1391	them non-ECMAscript-compliant). For example, Iceweasel reserves the
1241	C<__proto__> property name for it's own purposes.	1392	C<__proto__> property name for its own purposes.
1242		1393
1243	If that is a problem, you could parse try to filter the resulting JSON	1394	If that is a problem, you could parse try to filter the resulting JSON
1244	output for these property strings, e.g.:	1395	output for these property strings, e.g.:
1245		1396
1246	$json =~ s/"__proto__"\s*:/"__proto__renamed":/g;	1397	$json =~ s/"__proto__"\s*:/"__proto__renamed":/g;
1247		1398
1248	This works because C<__proto__> is not valid outside of strings, so every	1399	This works because C<__proto__> is not valid outside of strings, so every
1249	occurence of C<"__proto__"\s*:> must be a string used as property name.	1400	occurrence of C<"__proto__"\s*:> must be a string used as property name.
1250		1401
1251	If you know of other incompatibilities, please let me know.	1402	If you know of other incompatibilities, please let me know.
1252		1403
1253		1404
1254	=head2 JSON and YAML	1405	=head2 JSON and YAML
…		…
1266	my $yaml = $to_yaml->encode ($ref) . "\n";	1417	my $yaml = $to_yaml->encode ($ref) . "\n";
1267		1418
1268	This will I<usually> generate JSON texts that also parse as valid	1419	This will I<usually> generate JSON texts that also parse as valid
1269	YAML. Please note that YAML has hardcoded limits on (simple) object key	1420	YAML. Please note that YAML has hardcoded limits on (simple) object key
1270	lengths that JSON doesn't have and also has different and incompatible	1421	lengths that JSON doesn't have and also has different and incompatible
1271	unicode handling, so you should make sure that your hash keys are	1422	unicode character escape syntax, so you should make sure that your hash
1272	noticeably shorter than the 1024 "stream characters" YAML allows and that	1423	keys are noticeably shorter than the 1024 "stream characters" YAML allows
1273	you do not have characters with codepoint values outside the Unicode BMP	1424	and that you do not have characters with codepoint values outside the
1274	(basic multilingual page). YAML also does not allow C<\/> sequences in	1425	Unicode BMP (basic multilingual page). YAML also does not allow C<\/>
1275	strings (which JSON::XS does not I<currently> generate, but other JSON	1426	sequences in strings (which JSON::XS does not I<currently> generate, but
1276	generators might).	1427	other JSON generators might).
1277		1428
1278	There might be other incompatibilities that I am not aware of (or the YAML	1429	There might be other incompatibilities that I am not aware of (or the YAML
1279	specification has been changed yet again - it does so quite often). In	1430	specification has been changed yet again - it does so quite often). In
1280	general you should not try to generate YAML with a JSON generator or vice	1431	general you should not try to generate YAML with a JSON generator or vice
1281	versa, or try to parse JSON with a YAML parser or vice versa: chances are	1432	versa, or try to parse JSON with a YAML parser or vice versa: chances are
…		…
1300	that difficult or long) and finally make YAML compatible to it, and	1451	that difficult or long) and finally make YAML compatible to it, and
1301	educating users about the changes, instead of spreading lies about the	1452	educating users about the changes, instead of spreading lies about the
1302	real compatibility for many I<years> and trying to silence people who	1453	real compatibility for many I<years> and trying to silence people who
1303	point out that it isn't true.	1454	point out that it isn't true.
1304		1455
		1456	Addendum/2009: the YAML 1.2 spec is still incompatible with JSON, even
		1457	though the incompatibilities have been documented (and are known to Brian)
		1458	for many years and the spec makes explicit claims that YAML is a superset
		1459	of JSON. It would be so easy to fix, but apparently, bullying people and
		1460	corrupting userdata is so much easier.
		1461
1305	=back	1462	=back
1306		1463
1307		1464
1308	=head2 SPEED	1465	=head2 SPEED
1309		1466
…		…
1316	a very short single-line JSON string (also available at	1473	a very short single-line JSON string (also available at
1317	L<http://dist.schmorp.de/misc/json/short.json>).	1474	L<http://dist.schmorp.de/misc/json/short.json>).
1318		1475
1319	{"method": "handleMessage", "params": ["user1",	1476	{"method": "handleMessage", "params": ["user1",
1320	"we were just talking"], "id": null, "array":[1,11,234,-5,1e5,1e7,	1477	"we were just talking"], "id": null, "array":[1,11,234,-5,1e5,1e7,
1321	true, false]}	1478	1, 0]}
1322		1479
1323	It shows the number of encodes/decodes per second (JSON::XS uses	1480	It shows the number of encodes/decodes per second (JSON::XS uses
1324	the functional interface, while JSON::XS/2 uses the OO interface	1481	the functional interface, while JSON::XS/2 uses the OO interface
1325	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables	1482	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables
1326	shrink). Higher is better:	1483	shrink. JSON::DWIW/DS uses the deserialise function, while JSON::DWIW::FJ
		1484	uses the from_json method). Higher is better:
1327		1485
1328	module \| encode \| decode \|	1486	module \| encode \| decode \|
1329	-----------\|------------\|------------\|	1487	--------------\|------------\|------------\|
1330	JSON 1.x \| 4990.842 \| 4088.813 \|	1488	JSON::DWIW/DS \| 86302.551 \| 102300.098 \|
1331	JSON::DWIW \| 51653.990 \| 71575.154 \|	1489	JSON::DWIW/FJ \| 86302.551 \| 75983.768 \|
1332	JSON::PC \| 65948.176 \| 74631.744 \|	1490	JSON::PP \| 15827.562 \| 6638.658 \|
1333	JSON::PP \| 8931.652 \| 3817.168 \|	1491	JSON::Syck \| 63358.066 \| 47662.545 \|
1334	JSON::Syck \| 24877.248 \| 27776.848 \|	1492	JSON::XS \| 511500.488 \| 511500.488 \|
1335	JSON::XS \| 388361.481 \| 227951.304 \|	1493	JSON::XS/2 \| 291271.111 \| 388361.481 \|
1336	JSON::XS/2 \| 227951.304 \| 218453.333 \|	1494	JSON::XS/3 \| 361577.931 \| 361577.931 \|
1337	JSON::XS/3 \| 338250.323 \| 218453.333 \|	1495	Storable \| 66788.280 \| 265462.278 \|
1338	Storable \| 16500.016 \| 135300.129 \|
1339	-----------+------------+------------+	1496	--------------+------------+------------+
1340		1497
1341	That is, JSON::XS is about five times faster than JSON::DWIW on encoding,	1498	That is, JSON::XS is almost six times faster than JSON::DWIW on encoding,
1342	about three times faster on decoding, and over forty times faster	1499	about five times faster on decoding, and over thirty to seventy times
1343	than JSON, even with pretty-printing and key sorting. It also compares	1500	faster than JSON's pure perl implementation. It also compares favourably
1344	favourably to Storable for small amounts of data.	1501	to Storable for small amounts of data.
1345		1502
1346	Using a longer test string (roughly 18KB, generated from Yahoo! Locals	1503	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
1347	search API (L<http://dist.schmorp.de/misc/json/long.json>).	1504	search API (L<http://dist.schmorp.de/misc/json/long.json>).
1348		1505
1349	module \| encode \| decode \|	1506	module \| encode \| decode \|
1350	-----------\|------------\|------------\|	1507	--------------\|------------\|------------\|
1351	JSON 1.x \| 55.260 \| 34.971 \|	1508	JSON::DWIW/DS \| 1647.927 \| 2673.916 \|
1352	JSON::DWIW \| 825.228 \| 1082.513 \|	1509	JSON::DWIW/FJ \| 1630.249 \| 2596.128 \|
1353	JSON::PC \| 3571.444 \| 2394.829 \|
1354	JSON::PP \| 210.987 \| 32.574 \|	1510	JSON::PP \| 400.640 \| 62.311 \|
1355	JSON::Syck \| 552.551 \| 787.544 \|	1511	JSON::Syck \| 1481.040 \| 1524.869 \|
1356	JSON::XS \| 5780.463 \| 4854.519 \|	1512	JSON::XS \| 20661.596 \| 9541.183 \|
1357	JSON::XS/2 \| 3869.998 \| 4798.975 \|	1513	JSON::XS/2 \| 10683.403 \| 9416.938 \|
1358	JSON::XS/3 \| 5862.880 \| 4798.975 \|	1514	JSON::XS/3 \| 20661.596 \| 9400.054 \|
1359	Storable \| 4445.002 \| 5235.027 \|	1515	Storable \| 19765.806 \| 10000.725 \|
1360	-----------+------------+------------+	1516	--------------+------------+------------+
1361		1517
1362	Again, JSON::XS leads by far (except for Storable which non-surprisingly	1518	Again, JSON::XS leads by far (except for Storable which non-surprisingly
1363	decodes faster).	1519	decodes a bit faster).
1364		1520
1365	On large strings containing lots of high Unicode characters, some modules	1521	On large strings containing lots of high Unicode characters, some modules
1366	(such as JSON::PC) seem to decode faster than JSON::XS, but the result	1522	(such as JSON::PC) seem to decode faster than JSON::XS, but the result
1367	will be broken due to missing (or wrong) Unicode handling. Others refuse	1523	will be broken due to missing (or wrong) Unicode handling. Others refuse
1368	to decode or encode properly, so it was impossible to prepare a fair	1524	to decode or encode properly, so it was impossible to prepare a fair
…		…
1404	information you might want to make sure that exceptions thrown by JSON::XS	1560	information you might want to make sure that exceptions thrown by JSON::XS
1405	will not end up in front of untrusted eyes.	1561	will not end up in front of untrusted eyes.
1406		1562
1407	If you are using JSON::XS to return packets to consumption	1563	If you are using JSON::XS to return packets to consumption
1408	by JavaScript scripts in a browser you should have a look at	1564	by JavaScript scripts in a browser you should have a look at
1409	L<http://jpsykes.com/47/practical-csrf-and-json-security> to see whether	1565	L<http://blog.archive.jpsykes.com/47/practical-csrf-and-json-security/> to
1410	you are vulnerable to some common attack vectors (which really are browser	1566	see whether you are vulnerable to some common attack vectors (which really
1411	design bugs, but it is still you who will have to deal with it, as major	1567	are browser design bugs, but it is still you who will have to deal with
1412	browser developers care only for features, not about getting security	1568	it, as major browser developers care only for features, not about getting
1413	right).	1569	security right).
		1570
		1571
		1572	=head1 "OLD" VS. "NEW" JSON (RFC 4627 VS. RFC 7159)
		1573
		1574	TL;DR: Due to security concerns, JSON::XS will not allow scalar data in
		1575	JSON texts by default - you need to create your own JSON::XS object and
		1576	enable C<allow_nonref>:
		1577
		1578
		1579	my $json = JSON::XS->new->allow_nonref;
		1580
		1581	$text = $json->encode ($data);
		1582	$data = $json->decode ($text);
		1583
		1584	The long version: JSON being an important and supposedly stable format,
		1585	the IETF standardised it as RFC 4627 in 2006. Unfortunately, the inventor
		1586	of JSON, Dougles Crockford, unilaterally changed the definition of JSON in
		1587	javascript. Rather than create a fork, the IETF decided to standardise the
		1588	new syntax (apparently, so Iw as told, without finding it very amusing).
		1589
		1590	The biggest difference between thed original JSON and the new JSON is that
		1591	the new JSON supports scalars (anything other than arrays and objects) at
		1592	the toplevel of a JSON text. While this is strictly backwards compatible
		1593	to older versions, it breaks a number of protocols that relied on sending
		1594	JSON back-to-back, and is a minor security concern.
		1595
		1596	For example, imagine you have two banks communicating, and on one side,
		1597	trhe JSON coder gets upgraded. Two messages, such as C<10> and C<1000>
		1598	might then be confused to mean C<101000>, something that couldn't happen
		1599	in the original JSON, because niether of these messages would be valid
		1600	JSON.
		1601
		1602	If one side accepts these messages, then an upgrade in the coder on either
		1603	side could result in this becoming exploitable.
		1604
		1605	This module has always allowed these messages as an optional extension, by
		1606	default disabled. The security concerns are the reason why the default is
		1607	still disabled, but future versions might/will likely upgrade to the newer
		1608	RFC as default format, so you are advised to check your implementation
		1609	and/or override the default with C<< ->allow_nonref (0) >> to ensure that
		1610	future versions are safe.
		1611
		1612
		1613	=head1 INTEROPERABILITY WITH OTHER MODULES
		1614
		1615	C<JSON::XS> uses the L<Types::Serialiser> module to provide boolean
		1616	constants. That means that the JSON true and false values will be
		1617	comaptible to true and false values of other modules that do the same,
		1618	such as L<JSON::PP> and L<CBOR::XS>.
		1619
		1620
		1621	=head1 INTEROPERABILITY WITH OTHER JSON DECODERS
		1622
		1623	As long as you only serialise data that can be directly expressed in JSON,
		1624	C<JSON::XS> is incapable of generating invalid JSON output (modulo bugs,
		1625	but C<JSON::XS> has found more bugs in the official JSON testsuite (1)
		1626	than the official JSON testsuite has found in C<JSON::XS> (0)).
		1627
		1628	When you have trouble decoding JSON generated by this module using other
		1629	decoders, then it is very likely that you have an encoding mismatch or the
		1630	other decoder is broken.
		1631
		1632	When decoding, C<JSON::XS> is strict by default and will likely catch all
		1633	errors. There are currently two settings that change this: C<relaxed>
		1634	makes C<JSON::XS> accept (but not generate) some non-standard extensions,
		1635	and C<allow_tags> will allow you to encode and decode Perl objects, at the
		1636	cost of not outputting valid JSON anymore.
		1637
		1638	=head2 TAGGED VALUE SYNTAX AND STANDARD JSON EN/DECODERS
		1639
		1640	When you use C<allow_tags> to use the extended (and also nonstandard and
		1641	invalid) JSON syntax for serialised objects, and you still want to decode
		1642	the generated When you want to serialise objects, you can run a regex
		1643	to replace the tagged syntax by standard JSON arrays (it only works for
		1644	"normal" package names without comma, newlines or single colons). First,
		1645	the readable Perl version:
		1646
		1647	# if your FREEZE methods return no values, you need this replace first:
		1648	$json =~ s/$ \s* (" (?: [^\\":,]+\|\\.\|::)* ") \s* $ \s* \[\s*\]/[$1]/gx;
		1649
		1650	# this works for non-empty constructor arg lists:
		1651	$json =~ s/$ \s* (" (?: [^\\":,]+\|\\.\|::)* ") \s* $ \s* \[/[$1,/gx;
		1652
		1653	And here is a less readable version that is easy to adapt to other
		1654	languages:
		1655
		1656	$json =~ s/$\s("([^\\":,]+\|\\.\|::)")\s$\s\[/[$1,/g;
		1657
		1658	Here is an ECMAScript version (same regex):
		1659
		1660	json = json.replace (/$\s("([^\\":,]+\|\\.\|::)")\s$\s\[/g, "[$1,");
		1661
		1662	Since this syntax converts to standard JSON arrays, it might be hard to
		1663	distinguish serialised objects from normal arrays. You can prepend a
		1664	"magic number" as first array element to reduce chances of a collision:
		1665
		1666	$json =~ s/$\s("([^\\":,]+\|\\.\|::)")\s$\s\[/["XU1peReLzT4ggEllLanBYq4G9VzliwKF",$1,/g;
		1667
		1668	And after decoding the JSON text, you could walk the data
		1669	structure looking for arrays with a first element of
		1670	C<XU1peReLzT4ggEllLanBYq4G9VzliwKF>.
		1671
		1672	The same approach can be used to create the tagged format with another
		1673	encoder. First, you create an array with the magic string as first member,
		1674	the classname as second, and constructor arguments last, encode it as part
		1675	of your JSON structure, and then:
		1676
		1677	$json =~ s/\[\s"XU1peReLzT4ggEllLanBYq4G9VzliwKF"\s,\s("([^\\":,]+\|\\.\|::)")\s*,/($1)[/g;
		1678
		1679	Again, this has some limitations - the magic string must not be encoded
		1680	with character escapes, and the constructor arguments must be non-empty.
		1681
		1682
		1683	=head1 RFC7159
		1684
		1685	Since this module was written, Google has written a new JSON RFC, RFC 7159
		1686	(and RFC7158). Unfortunately, this RFC breaks compatibility with both the
		1687	original JSON specification on www.json.org and RFC4627.
		1688
		1689	As far as I can see, you can get partial compatibility when parsing by
		1690	using C<< ->allow_nonref >>. However, consider the security implications
		1691	of doing so.
		1692
		1693	I haven't decided yet when to break compatibility with RFC4627 by default
		1694	(and potentially leave applications insecure) and change the default to
		1695	follow RFC7159, but application authors are well advised to call C<<
		1696	->allow_nonref(0) >> even if this is the current default, if they cannot
		1697	handle non-reference values, in preparation for the day when the default
		1698	will change.
1414		1699
1415		1700
1416	=head1 THREADS	1701	=head1 THREADS
1417		1702
1418	This module is I<not> guaranteed to be thread safe and there are no	1703	This module is I<not> guaranteed to be thread safe and there are no
…		…
1421	process simulations - use fork, it's I<much> faster, cheaper, better).	1706	process simulations - use fork, it's I<much> faster, cheaper, better).
1422		1707
1423	(It might actually work, but you have been warned).	1708	(It might actually work, but you have been warned).
1424		1709
1425		1710
		1711	=head1 THE PERILS OF SETLOCALE
		1712
		1713	Sometimes people avoid the Perl locale support and directly call the
		1714	system's setlocale function with C<LC_ALL>.
		1715
		1716	This breaks both perl and modules such as JSON::XS, as stringification of
		1717	numbers no longer works correctly (e.g. C<$x = 0.1; print "$x"+1> might
		1718	print C<1>, and JSON::XS might output illegal JSON as JSON::XS relies on
		1719	perl to stringify numbers).
		1720
		1721	The solution is simple: don't call C<setlocale>, or use it for only those
		1722	categories you need, such as C<LC_MESSAGES> or C<LC_CTYPE>.
		1723
		1724	If you need C<LC_NUMERIC>, you should enable it only around the code that
		1725	actually needs it (avoiding stringification of numbers), and restore it
		1726	afterwards.
		1727
		1728
1426	=head1 BUGS	1729	=head1 BUGS
1427		1730
1428	While the goal of this module is to be correct, that unfortunately does	1731	While the goal of this module is to be correct, that unfortunately does
1429	not mean it's bug-free, only that I think its design is bug-free. If you	1732	not mean it's bug-free, only that I think its design is bug-free. If you
1430	keep reporting bugs they will be fixed swiftly, though.	1733	keep reporting bugs they will be fixed swiftly, though.
…		…
1432	Please refrain from using rt.cpan.org or any other bug reporting	1735	Please refrain from using rt.cpan.org or any other bug reporting
1433	service. I put the contact address into my modules for a reason.	1736	service. I put the contact address into my modules for a reason.
1434		1737
1435	=cut	1738	=cut
1436		1739
1437	our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" };	1740	BEGIN {
1438	our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" };	1741	*true = \$Types::Serialiser::true;
		1742	*true = \&Types::Serialiser::true;
		1743	*false = \$Types::Serialiser::false;
		1744	*false = \&Types::Serialiser::false;
		1745	*is_bool = \&Types::Serialiser::is_bool;
1439		1746
1440	sub true() { $true }	1747	JSON::XS::Boolean:: = Types::Serialiser::Boolean::;
1441	sub false() { $false }
1442
1443	sub is_bool($) {
1444	UNIVERSAL::isa $_[0], "JSON::XS::Boolean"
1445	# or UNIVERSAL::isa $_[0], "JSON::Literal"
1446	}	1748	}
1447		1749
1448	XSLoader::load "JSON::XS", $VERSION;	1750	XSLoader::load "JSON::XS", $VERSION;
1449
1450	package JSON::XS::Boolean;
1451
1452	use overload
1453	"0+" => sub { ${$_[0]} },
1454	"++" => sub { $_[0] = ${$_[0]} + 1 },
1455	"--" => sub { $_[0] = ${$_[0]} - 1 },
1456	fallback => 1;
1457
1458	1;
1459		1751
1460	=head1 SEE ALSO	1752	=head1 SEE ALSO
1461		1753
1462	The F<json_xs> command line utility for quick experiments.	1754	The F<json_xs> command line utility for quick experiments.
1463		1755
…		…
1466	Marc Lehmann <schmorp@schmorp.de>	1758	Marc Lehmann <schmorp@schmorp.de>
1467	http://home.schmorp.de/	1759	http://home.schmorp.de/
1468		1760
1469	=cut	1761	=cut
1470		1762
		1763	1
		1764

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Comparing JSON-XS/XS.pm (file contents): Revision 1.121 by root, Mon Jul 13 22:13:17 2009 UTC vs. Revision 1.160 by root, Wed Nov 16 18:08:30 2016 UTC

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Comparing JSON-XS/XS.pm (file contents):
Revision 1.121 by root, Mon Jul 13 22:13:17 2009 UTC vs.
Revision 1.160 by root, Wed Nov 16 18:08:30 2016 UTC