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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.115 by root, Tue Feb 17 23:29:38 2009 UTC vs.
Revision 1.144 by root, Mon Oct 28 23:19:54 2013 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
…		…
99		99
100	=cut	100	=cut
101		101
102	package JSON::XS;	102	package JSON::XS;
103		103
104	no warnings;	104	use common::sense;
105	use strict;
106		105
107	our $VERSION = '2.232';	106	our $VERSION = 2.34;
108	our @ISA = qw(Exporter);	107	our @ISA = qw(Exporter);
109		108
110	our @EXPORT = qw(encode_json decode_json to_json from_json);	109	our @EXPORT = qw(encode_json decode_json);
111
112	sub to_json($) {
113	require Carp;
114	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");
115	}
116
117	sub from_json($) {
118	require Carp;
119	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");
120	}
121		110
122	use Exporter;	111	use Exporter;
123	use XSLoader;	112	use XSLoader;
		113
		114	use Types::Serialiser ();
124		115
125	=head1 FUNCTIONAL INTERFACE	116	=head1 FUNCTIONAL INTERFACE
126		117
127	The following convenience methods are provided by this module. They are	118	The following convenience methods are provided by this module. They are
128	exported by default:	119	exported by default:
…		…
149	This function call is functionally identical to:	140	This function call is functionally identical to:
150		141
151	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)	142	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)
152		143
153	Except being faster.	144	Except being faster.
154
155	=item $is_boolean = JSON::XS::is_bool $scalar
156
157	Returns true if the passed scalar represents either JSON::XS::true or
158	JSON::XS::false, two constants that act like C<1> and C<0>, respectively
159	and are used to represent JSON C<true> and C<false> values in Perl.
160
161	See MAPPING, below, for more information on how JSON values are mapped to
162	Perl.
163		145
164	=back	146	=back
165		147
166		148
167	=head1 A FEW NOTES ON UNICODE AND PERL	149	=head1 A FEW NOTES ON UNICODE AND PERL
…		…
433	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects	415	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects
434	by sorting their keys. This is adding a comparatively high overhead.	416	by sorting their keys. This is adding a comparatively high overhead.
435		417
436	If C<$enable> is false, then the C<encode> method will output key-value	418	If C<$enable> is false, then the C<encode> method will output key-value
437	pairs in the order Perl stores them (which will likely change between runs	419	pairs in the order Perl stores them (which will likely change between runs
438	of the same script).	420	of the same script, and can change even within the same run from 5.18
		421	onwards).
439		422
440	This option is useful if you want the same data structure to be encoded as	423	This option is useful if you want the same data structure to be encoded as
441	the same JSON text (given the same overall settings). If it is disabled,	424	the same JSON text (given the same overall settings). If it is disabled,
442	the same hash might be encoded differently even if contains the same data,	425	the same hash might be encoded differently even if contains the same data,
443	as key-value pairs have no inherent ordering in Perl.	426	as key-value pairs have no inherent ordering in Perl.
444		427
445	This setting has no effect when decoding JSON texts.	428	This setting has no effect when decoding JSON texts.
		429
		430	This setting has currently no effect on tied hashes.
446		431
447	=item $json = $json->allow_nonref ([$enable])	432	=item $json = $json->allow_nonref ([$enable])
448		433
449	=item $enabled = $json->get_allow_nonref	434	=item $enabled = $json->get_allow_nonref
450		435
…		…
665		650
666	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.	651	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
667		652
668	=item $json_text = $json->encode ($perl_scalar)	653	=item $json_text = $json->encode ($perl_scalar)
669		654
670	Converts the given Perl data structure (a simple scalar or a reference	655	Converts the given Perl value or data structure to its JSON
671	to a hash or array) to its JSON representation. Simple scalars will be	656	representation. Croaks on error.
672	converted into JSON string or number sequences, while references to arrays
673	become JSON arrays and references to hashes become JSON objects. Undefined
674	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>
675	nor C<false> values will be generated.
676		657
677	=item $perl_scalar = $json->decode ($json_text)	658	=item $perl_scalar = $json->decode ($json_text)
678		659
679	The opposite of C<encode>: expects a JSON text and tries to parse it,	660	The opposite of C<encode>: expects a JSON text and tries to parse it,
680	returning the resulting simple scalar or reference. Croaks on error.	661	returning the resulting simple scalar or reference. Croaks on error.
681
682	JSON numbers and strings become simple Perl scalars. JSON arrays become
683	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes
684	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.
685		662
686	=item ($perl_scalar, $characters) = $json->decode_prefix ($json_text)	663	=item ($perl_scalar, $characters) = $json->decode_prefix ($json_text)
687		664
688	This works like the C<decode> method, but instead of raising an exception	665	This works like the C<decode> method, but instead of raising an exception
689	when there is trailing garbage after the first JSON object, it will	666	when there is trailing garbage after the first JSON object, it will
690	silently stop parsing there and return the number of characters consumed	667	silently stop parsing there and return the number of characters consumed
691	so far.	668	so far.
692		669
693	This is useful if your JSON texts are not delimited by an outer protocol	670	This is useful if your JSON texts are not delimited by an outer protocol
694	(which is not the brightest thing to do in the first place) and you need
695	to know where the JSON text ends.	671	and you need to know where the JSON text ends.
696		672
697	JSON::XS->new->decode_prefix ("[1] the tail")	673	JSON::XS->new->decode_prefix ("[1] the tail")
698	=> ([], 3)	674	=> ([], 3)
699		675
700	=back	676	=back
…		…
712	calls).	688	calls).
713		689
714	JSON::XS will only attempt to parse the JSON text once it is sure it	690	JSON::XS will only attempt to parse the JSON text once it is sure it
715	has enough text to get a decisive result, using a very simple but	691	has enough text to get a decisive result, using a very simple but
716	truly incremental parser. This means that it sometimes won't stop as	692	truly incremental parser. This means that it sometimes won't stop as
717	early as the full parser, for example, it doesn't detect parenthese	693	early as the full parser, for example, it doesn't detect mismatched
718	mismatches. The only thing it guarantees is that it starts decoding as	694	parentheses. The only thing it guarantees is that it starts decoding as
719	soon as a syntactically valid JSON text has been seen. This means you need	695	soon as a syntactically valid JSON text has been seen. This means you need
720	to set resource limits (e.g. C<max_size>) to ensure the parser will stop	696	to set resource limits (e.g. C<max_size>) to ensure the parser will stop
721	parsing in the presence if syntax errors.	697	parsing in the presence if syntax errors.
722		698
723	The following methods implement this incremental parser.	699	The following methods implement this incremental parser.
…		…
739		715
740	If the method is called in scalar context, then it will try to extract	716	If the method is called in scalar context, then it will try to extract
741	exactly I<one> JSON object. If that is successful, it will return this	717	exactly I<one> JSON object. If that is successful, it will return this
742	object, otherwise it will return C<undef>. If there is a parse error,	718	object, otherwise it will return C<undef>. If there is a parse error,
743	this method will croak just as C<decode> would do (one can then use	719	this method will croak just as C<decode> would do (one can then use
744	C<incr_skip> to skip the errornous part). This is the most common way of	720	C<incr_skip> to skip the erroneous part). This is the most common way of
745	using the method.	721	using the method.
746		722
747	And finally, in list context, it will try to extract as many objects	723	And finally, in list context, it will try to extract as many objects
748	from the stream as it can find and return them, or the empty list	724	from the stream as it can find and return them, or the empty list
749	otherwise. For this to work, there must be no separators between the JSON	725	otherwise. For this to work, there must be no separators between the JSON
750	objects or arrays, instead they must be concatenated back-to-back. If	726	objects or arrays, instead they must be concatenated back-to-back. If
751	an error occurs, an exception will be raised as in the scalar context	727	an error occurs, an exception will be raised as in the scalar context
752	case. Note that in this case, any previously-parsed JSON texts will be	728	case. Note that in this case, any previously-parsed JSON texts will be
753	lost.	729	lost.
754		730
		731	Example: Parse some JSON arrays/objects in a given string and return
		732	them.
		733
		734	my @objs = JSON::XS->new->incr_parse ("[5][7][1,2]");
		735
755	=item $lvalue_string = $json->incr_text	736	=item $lvalue_string = $json->incr_text
756		737
757	This method returns the currently stored JSON fragment as an lvalue, that	738	This method returns the currently stored JSON fragment as an lvalue, that
758	is, you can manipulate it. This I<only> works when a preceding call to	739	is, you can manipulate it. This I<only> works when a preceding call to
759	C<incr_parse> in I<scalar context> successfully returned an object. Under	740	C<incr_parse> in I<scalar context> successfully returned an object. Under
…		…
773	C<incr_parse> died, in which case the input buffer and incremental parser	754	C<incr_parse> died, in which case the input buffer and incremental parser
774	state is left unchanged, to skip the text parsed so far and to reset the	755	state is left unchanged, to skip the text parsed so far and to reset the
775	parse state.	756	parse state.
776		757
777	The difference to C<incr_reset> is that only text until the parse error	758	The difference to C<incr_reset> is that only text until the parse error
778	occured is removed.	759	occurred is removed.
779		760
780	=item $json->incr_reset	761	=item $json->incr_reset
781		762
782	This completely resets the incremental parser, that is, after this call,	763	This completely resets the incremental parser, that is, after this call,
783	it will be as if the parser had never parsed anything.	764	it will be as if the parser had never parsed anything.
…		…
789	=back	770	=back
790		771
791	=head2 LIMITATIONS	772	=head2 LIMITATIONS
792		773
793	All options that affect decoding are supported, except	774	All options that affect decoding are supported, except
794	C<allow_nonref>. The reason for this is that it cannot be made to	775	C<allow_nonref>. The reason for this is that it cannot be made to work
795	work sensibly: JSON objects and arrays are self-delimited, i.e. you can concatenate	776	sensibly: JSON objects and arrays are self-delimited, i.e. you can
796	them back to back and still decode them perfectly. This does not hold true	777	concatenate them back to back and still decode them perfectly. This does
797	for JSON numbers, however.	778	not hold true for JSON numbers, however.
798		779
799	For example, is the string C<1> a single JSON number, or is it simply the	780	For example, is the string C<1> a single JSON number, or is it simply the
800	start of C<12>? Or is C<12> a single JSON number, or the concatenation	781	start of C<12>? Or is C<12> a single JSON number, or the concatenation
801	of C<1> and C<2>? In neither case you can tell, and this is why JSON::XS	782	of C<1> and C<2>? In neither case you can tell, and this is why JSON::XS
802	takes the conservative route and disallows this case.	783	takes the conservative route and disallows this case.
…		…
981	If the number consists of digits only, JSON::XS will try to represent	962	If the number consists of digits only, JSON::XS will try to represent
982	it as an integer value. If that fails, it will try to represent it as	963	it as an integer value. If that fails, it will try to represent it as
983	a numeric (floating point) value if that is possible without loss of	964	a numeric (floating point) value if that is possible without loss of
984	precision. Otherwise it will preserve the number as a string value (in	965	precision. Otherwise it will preserve the number as a string value (in
985	which case you lose roundtripping ability, as the JSON number will be	966	which case you lose roundtripping ability, as the JSON number will be
986	re-encoded toa JSON string).	967	re-encoded to a JSON string).
987		968
988	Numbers containing a fractional or exponential part will always be	969	Numbers containing a fractional or exponential part will always be
989	represented as numeric (floating point) values, possibly at a loss of	970	represented as numeric (floating point) values, possibly at a loss of
990	precision (in which case you might lose perfect roundtripping ability, but	971	precision (in which case you might lose perfect roundtripping ability, but
991	the JSON number will still be re-encoded as a JSON number).	972	the JSON number will still be re-encoded as a JSON number).
992		973
		974	Note that precision is not accuracy - binary floating point values cannot
		975	represent most decimal fractions exactly, and when converting from and to
		976	floating point, JSON::XS only guarantees precision up to but not including
		977	the least significant bit.
		978
993	=item true, false	979	=item true, false
994		980
995	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,	981	These JSON atoms become C<Types::Serialiser::true> and
996	respectively. They are overloaded to act almost exactly like the numbers	982	C<Types::Serialiser::false>, respectively. They are overloaded to act
997	C<1> and C<0>. You can check whether a scalar is a JSON boolean by using	983	almost exactly like the numbers C<1> and C<0>. You can check whether
998	the C<JSON::XS::is_bool> function.	984	a scalar is a JSON boolean by using the C<Types::Serialiser::is_bool>
		985	function (after C<use Types::Serialier>, of course).
999		986
1000	=item null	987	=item null
1001		988
1002	A JSON null atom becomes C<undef> in Perl.	989	A JSON null atom becomes C<undef> in Perl.
1003		990
…		…
1012		999
1013	=over 4	1000	=over 4
1014		1001
1015	=item hash references	1002	=item hash references
1016		1003
1017	Perl hash references become JSON objects. As there is no inherent ordering	1004	Perl hash references become JSON objects. As there is no inherent
1018	in hash keys (or JSON objects), they will usually be encoded in a	1005	ordering in hash keys (or JSON objects), they will usually be encoded
1019	pseudo-random order that can change between runs of the same program but	1006	in a pseudo-random order. JSON::XS can optionally sort the hash keys
1020	stays generally the same within a single run of a program. JSON::XS can	1007	(determined by the I<canonical> flag), so the same datastructure will
1021	optionally sort the hash keys (determined by the I<canonical> flag), so	1008	serialise to the same JSON text (given same settings and version of
1022	the same datastructure will serialise to the same JSON text (given same	1009	JSON::XS), but this incurs a runtime overhead and is only rarely useful,
1023	settings and version of JSON::XS), but this incurs a runtime overhead	1010	e.g. when you want to compare some JSON text against another for equality.
1024	and is only rarely useful, e.g. when you want to compare some JSON text
1025	against another for equality.
1026		1011
1027	=item array references	1012	=item array references
1028		1013
1029	Perl array references become JSON arrays.	1014	Perl array references become JSON arrays.
1030		1015
1031	=item other references	1016	=item other references
1032		1017
1033	Other unblessed references are generally not allowed and will cause an	1018	Other unblessed references are generally not allowed and will cause an
1034	exception to be thrown, except for references to the integers C<0> and	1019	exception to be thrown, except for references to the integers C<0> and
1035	C<1>, which get turned into C<false> and C<true> atoms in JSON. You can	1020	C<1>, which get turned into C<false> and C<true> atoms in JSON.
1036	also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability.
1037		1021
		1022	Since C<JSON::XS> uses the boolean model from L<Types::Serialiser>, you
		1023	can also C<use Types::Serialiser> and then use C<Types::Serialiser::false>
		1024	and C<Types::Serialiser::true> to improve readability.
		1025
		1026	use Types::Serialiser;
1038	encode_json [\0, JSON::XS::true] # yields [false,true]	1027	encode_json [\0, Types::Serialiser::true] # yields [false,true]
1039		1028
1040	=item JSON::XS::true, JSON::XS::false	1029	=item Types::Serialiser::true, Types::Serialiser::false
1041		1030
1042	These special values become JSON true and JSON false values,	1031	These special values from the L<Types::Serialiser> module become JSON true
1043	respectively. You can also use C<\1> and C<\0> directly if you want.	1032	and JSON false values, respectively. You can also use C<\1> and C<\0>
		1033	directly if you want.
1044		1034
1045	=item blessed objects	1035	=item blessed objects
1046		1036
1047	Blessed objects are not directly representable in JSON. See the	1037	Blessed objects are not directly representable in JSON. See the
1048	C<allow_blessed> and C<convert_blessed> methods on various options on	1038	C<allow_blessed> and C<convert_blessed> methods on various options on
…		…
1083	$x *= 1; # same thing, the choice is yours.	1073	$x *= 1; # same thing, the choice is yours.
1084		1074
1085	You can not currently force the type in other, less obscure, ways. Tell me	1075	You can not currently force the type in other, less obscure, ways. Tell me
1086	if you need this capability (but don't forget to explain why it's needed	1076	if you need this capability (but don't forget to explain why it's needed
1087	:).	1077	:).
		1078
		1079	Note that numerical precision has the same meaning as under Perl (so
		1080	binary to decimal conversion follows the same rules as in Perl, which
		1081	can differ to other languages). Also, your perl interpreter might expose
		1082	extensions to the floating point numbers of your platform, such as
		1083	infinities or NaN's - these cannot be represented in JSON, and it is an
		1084	error to pass those in.
1088		1085
1089	=back	1086	=back
1090		1087
1091		1088
1092	=head1 ENCODING/CODESET FLAG NOTES	1089	=head1 ENCODING/CODESET FLAG NOTES
…		…
1119	=item C<utf8> flag disabled	1116	=item C<utf8> flag disabled
1120		1117
1121	When C<utf8> is disabled (the default), then C<encode>/C<decode> generate	1118	When C<utf8> is disabled (the default), then C<encode>/C<decode> generate
1122	and expect Unicode strings, that is, characters with high ordinal Unicode	1119	and expect Unicode strings, that is, characters with high ordinal Unicode
1123	values (> 255) will be encoded as such characters, and likewise such	1120	values (> 255) will be encoded as such characters, and likewise such
1124	characters are decoded as-is, no canges to them will be done, except	1121	characters are decoded as-is, no changes to them will be done, except
1125	"(re-)interpreting" them as Unicode codepoints or Unicode characters,	1122	"(re-)interpreting" them as Unicode codepoints or Unicode characters,
1126	respectively (to Perl, these are the same thing in strings unless you do	1123	respectively (to Perl, these are the same thing in strings unless you do
1127	funny/weird/dumb stuff).	1124	funny/weird/dumb stuff).
1128		1125
1129	This is useful when you want to do the encoding yourself (e.g. when you	1126	This is useful when you want to do the encoding yourself (e.g. when you
…		…
1209	use JSON::XS;	1206	use JSON::XS;
1210		1207
1211	print encode_json [chr 0x2028];	1208	print encode_json [chr 0x2028];
1212		1209
1213	The right fix for this is to use a proper JSON parser in your javascript	1210	The right fix for this is to use a proper JSON parser in your javascript
1214	programs, and not rely on C<eval>.	1211	programs, and not rely on C<eval> (see for example Douglas Crockford's
		1212	F<json2.js> parser).
1215		1213
1216	If this is not an option, you can, as a stop-gap measure, simply encode to	1214	If this is not an option, you can, as a stop-gap measure, simply encode to
1217	ASCII-only JSON:	1215	ASCII-only JSON:
1218		1216
1219	use JSON::XS;	1217	use JSON::XS;
1220		1218
1221	print JSON::XS->new->ascii->encode ([chr 0x2028]);	1219	print JSON::XS->new->ascii->encode ([chr 0x2028]);
1222		1220
1223	And if you are concerned about the size of the resulting JSON text, you	1221	Note that this will enlarge the resulting JSON text quite a bit if you
1224	can run some regexes to only escape U+2028 and U+2029:	1222	have many non-ASCII characters. You might be tempted to run some regexes
		1223	to only escape U+2028 and U+2029, e.g.:
1225		1224
1226	use JSON::XS;	1225	# DO NOT USE THIS!
1227
1228	my $json = JSON::XS->new->utf8->encode ([chr 0x2028]);	1226	my $json = JSON::XS->new->utf8->encode ([chr 0x2028]);
1229	$json =~ s/\xe2\x80\xa8/\\u2028/g; # escape U+2028	1227	$json =~ s/\xe2\x80\xa8/\\u2028/g; # escape U+2028
1230	$json =~ s/\xe2\x80\xa9/\\u2029/g; # escape U+2029	1228	$json =~ s/\xe2\x80\xa9/\\u2029/g; # escape U+2029
1231	print $json;	1229	print $json;
1232		1230
1233	This works because U+2028/U+2029 are not allowed outside of strings and	1231	Note that I<this is a bad idea>: the above only works for U+2028 and
1234	are not used for syntax, so replacing them unconditionally just works.	1232	U+2029 and thus only for fully ECMAscript-compliant parsers. Many existing
1235		1233	javascript implementations, however, have issues with other characters as
1236	Note, however, that fixing the broken JSON parser is better than working	1234	well - using C<eval> naively simply I<will> cause problems.
1237	around it in every other generator. The above regexes should work well in
1238	other languages, as long as they operate on UTF-8. It is equally valid to
1239	replace all occurences of U+2028/2029 directly by their \\u-escaped forms
1240	in unicode texts, so they can simply be used to fix any parsers relying on
1241	C<eval> by first applying the regexes on the encoded texts.
1242		1235
1243	Another problem is that some javascript implementations reserve	1236	Another problem is that some javascript implementations reserve
1244	some property names for their own purposes (which probably makes	1237	some property names for their own purposes (which probably makes
1245	them non-ECMAscript-compliant). For example, Iceweasel reserves the	1238	them non-ECMAscript-compliant). For example, Iceweasel reserves the
1246	C<__proto__> property name for it's own purposes.	1239	C<__proto__> property name for its own purposes.
1247		1240
1248	If that is a problem, you could parse try to filter the resulting JSON	1241	If that is a problem, you could parse try to filter the resulting JSON
1249	output for these property strings, e.g.:	1242	output for these property strings, e.g.:
1250		1243
1251	$json =~ s/"__proto__"\s*:/"__proto__renamed":/g;	1244	$json =~ s/"__proto__"\s*:/"__proto__renamed":/g;
1252		1245
1253	This works because C<__proto__> is not valid outside of strings, so every	1246	This works because C<__proto__> is not valid outside of strings, so every
1254	occurence of C<"__proto__"\s*:> must be a string used as property name.	1247	occurrence of C<"__proto__"\s*:> must be a string used as property name.
1255		1248
1256	If you know of other incompatibilities, please let me know.	1249	If you know of other incompatibilities, please let me know.
1257		1250
1258		1251
1259	=head2 JSON and YAML	1252	=head2 JSON and YAML
…		…
1271	my $yaml = $to_yaml->encode ($ref) . "\n";	1264	my $yaml = $to_yaml->encode ($ref) . "\n";
1272		1265
1273	This will I<usually> generate JSON texts that also parse as valid	1266	This will I<usually> generate JSON texts that also parse as valid
1274	YAML. Please note that YAML has hardcoded limits on (simple) object key	1267	YAML. Please note that YAML has hardcoded limits on (simple) object key
1275	lengths that JSON doesn't have and also has different and incompatible	1268	lengths that JSON doesn't have and also has different and incompatible
1276	unicode handling, so you should make sure that your hash keys are	1269	unicode character escape syntax, so you should make sure that your hash
1277	noticeably shorter than the 1024 "stream characters" YAML allows and that	1270	keys are noticeably shorter than the 1024 "stream characters" YAML allows
1278	you do not have characters with codepoint values outside the Unicode BMP	1271	and that you do not have characters with codepoint values outside the
1279	(basic multilingual page). YAML also does not allow C<\/> sequences in	1272	Unicode BMP (basic multilingual page). YAML also does not allow C<\/>
1280	strings (which JSON::XS does not I<currently> generate, but other JSON	1273	sequences in strings (which JSON::XS does not I<currently> generate, but
1281	generators might).	1274	other JSON generators might).
1282		1275
1283	There might be other incompatibilities that I am not aware of (or the YAML	1276	There might be other incompatibilities that I am not aware of (or the YAML
1284	specification has been changed yet again - it does so quite often). In	1277	specification has been changed yet again - it does so quite often). In
1285	general you should not try to generate YAML with a JSON generator or vice	1278	general you should not try to generate YAML with a JSON generator or vice
1286	versa, or try to parse JSON with a YAML parser or vice versa: chances are	1279	versa, or try to parse JSON with a YAML parser or vice versa: chances are
…		…
1305	that difficult or long) and finally make YAML compatible to it, and	1298	that difficult or long) and finally make YAML compatible to it, and
1306	educating users about the changes, instead of spreading lies about the	1299	educating users about the changes, instead of spreading lies about the
1307	real compatibility for many I<years> and trying to silence people who	1300	real compatibility for many I<years> and trying to silence people who
1308	point out that it isn't true.	1301	point out that it isn't true.
1309		1302
		1303	Addendum/2009: the YAML 1.2 spec is still incompatible with JSON, even
		1304	though the incompatibilities have been documented (and are known to Brian)
		1305	for many years and the spec makes explicit claims that YAML is a superset
		1306	of JSON. It would be so easy to fix, but apparently, bullying people and
		1307	corrupting userdata is so much easier.
		1308
1310	=back	1309	=back
1311		1310
1312		1311
1313	=head2 SPEED	1312	=head2 SPEED
1314		1313
…		…
1321	a very short single-line JSON string (also available at	1320	a very short single-line JSON string (also available at
1322	L<http://dist.schmorp.de/misc/json/short.json>).	1321	L<http://dist.schmorp.de/misc/json/short.json>).
1323		1322
1324	{"method": "handleMessage", "params": ["user1",	1323	{"method": "handleMessage", "params": ["user1",
1325	"we were just talking"], "id": null, "array":[1,11,234,-5,1e5,1e7,	1324	"we were just talking"], "id": null, "array":[1,11,234,-5,1e5,1e7,
1326	true, false]}	1325	1, 0]}
1327		1326
1328	It shows the number of encodes/decodes per second (JSON::XS uses	1327	It shows the number of encodes/decodes per second (JSON::XS uses
1329	the functional interface, while JSON::XS/2 uses the OO interface	1328	the functional interface, while JSON::XS/2 uses the OO interface
1330	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables	1329	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables
1331	shrink). Higher is better:	1330	shrink. JSON::DWIW/DS uses the deserialise function, while JSON::DWIW::FJ
		1331	uses the from_json method). Higher is better:
1332		1332
1333	module \| encode \| decode \|	1333	module \| encode \| decode \|
1334	-----------\|------------\|------------\|	1334	--------------\|------------\|------------\|
1335	JSON 1.x \| 4990.842 \| 4088.813 \|	1335	JSON::DWIW/DS \| 86302.551 \| 102300.098 \|
1336	JSON::DWIW \| 51653.990 \| 71575.154 \|	1336	JSON::DWIW/FJ \| 86302.551 \| 75983.768 \|
1337	JSON::PC \| 65948.176 \| 74631.744 \|	1337	JSON::PP \| 15827.562 \| 6638.658 \|
1338	JSON::PP \| 8931.652 \| 3817.168 \|	1338	JSON::Syck \| 63358.066 \| 47662.545 \|
1339	JSON::Syck \| 24877.248 \| 27776.848 \|	1339	JSON::XS \| 511500.488 \| 511500.488 \|
1340	JSON::XS \| 388361.481 \| 227951.304 \|	1340	JSON::XS/2 \| 291271.111 \| 388361.481 \|
1341	JSON::XS/2 \| 227951.304 \| 218453.333 \|	1341	JSON::XS/3 \| 361577.931 \| 361577.931 \|
1342	JSON::XS/3 \| 338250.323 \| 218453.333 \|	1342	Storable \| 66788.280 \| 265462.278 \|
1343	Storable \| 16500.016 \| 135300.129 \|
1344	-----------+------------+------------+	1343	--------------+------------+------------+
1345		1344
1346	That is, JSON::XS is about five times faster than JSON::DWIW on encoding,	1345	That is, JSON::XS is almost six times faster than JSON::DWIW on encoding,
1347	about three times faster on decoding, and over forty times faster	1346	about five times faster on decoding, and over thirty to seventy times
1348	than JSON, even with pretty-printing and key sorting. It also compares	1347	faster than JSON's pure perl implementation. It also compares favourably
1349	favourably to Storable for small amounts of data.	1348	to Storable for small amounts of data.
1350		1349
1351	Using a longer test string (roughly 18KB, generated from Yahoo! Locals	1350	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
1352	search API (L<http://dist.schmorp.de/misc/json/long.json>).	1351	search API (L<http://dist.schmorp.de/misc/json/long.json>).
1353		1352
1354	module \| encode \| decode \|	1353	module \| encode \| decode \|
1355	-----------\|------------\|------------\|	1354	--------------\|------------\|------------\|
1356	JSON 1.x \| 55.260 \| 34.971 \|	1355	JSON::DWIW/DS \| 1647.927 \| 2673.916 \|
1357	JSON::DWIW \| 825.228 \| 1082.513 \|	1356	JSON::DWIW/FJ \| 1630.249 \| 2596.128 \|
1358	JSON::PC \| 3571.444 \| 2394.829 \|
1359	JSON::PP \| 210.987 \| 32.574 \|	1357	JSON::PP \| 400.640 \| 62.311 \|
1360	JSON::Syck \| 552.551 \| 787.544 \|	1358	JSON::Syck \| 1481.040 \| 1524.869 \|
1361	JSON::XS \| 5780.463 \| 4854.519 \|	1359	JSON::XS \| 20661.596 \| 9541.183 \|
1362	JSON::XS/2 \| 3869.998 \| 4798.975 \|	1360	JSON::XS/2 \| 10683.403 \| 9416.938 \|
1363	JSON::XS/3 \| 5862.880 \| 4798.975 \|	1361	JSON::XS/3 \| 20661.596 \| 9400.054 \|
1364	Storable \| 4445.002 \| 5235.027 \|	1362	Storable \| 19765.806 \| 10000.725 \|
1365	-----------+------------+------------+	1363	--------------+------------+------------+
1366		1364
1367	Again, JSON::XS leads by far (except for Storable which non-surprisingly	1365	Again, JSON::XS leads by far (except for Storable which non-surprisingly
1368	decodes faster).	1366	decodes a bit faster).
1369		1367
1370	On large strings containing lots of high Unicode characters, some modules	1368	On large strings containing lots of high Unicode characters, some modules
1371	(such as JSON::PC) seem to decode faster than JSON::XS, but the result	1369	(such as JSON::PC) seem to decode faster than JSON::XS, but the result
1372	will be broken due to missing (or wrong) Unicode handling. Others refuse	1370	will be broken due to missing (or wrong) Unicode handling. Others refuse
1373	to decode or encode properly, so it was impossible to prepare a fair	1371	to decode or encode properly, so it was impossible to prepare a fair
…		…
1409	information you might want to make sure that exceptions thrown by JSON::XS	1407	information you might want to make sure that exceptions thrown by JSON::XS
1410	will not end up in front of untrusted eyes.	1408	will not end up in front of untrusted eyes.
1411		1409
1412	If you are using JSON::XS to return packets to consumption	1410	If you are using JSON::XS to return packets to consumption
1413	by JavaScript scripts in a browser you should have a look at	1411	by JavaScript scripts in a browser you should have a look at
1414	L<http://jpsykes.com/47/practical-csrf-and-json-security> to see whether	1412	L<http://blog.archive.jpsykes.com/47/practical-csrf-and-json-security/> to
1415	you are vulnerable to some common attack vectors (which really are browser	1413	see whether you are vulnerable to some common attack vectors (which really
1416	design bugs, but it is still you who will have to deal with it, as major	1414	are browser design bugs, but it is still you who will have to deal with
1417	browser developers care only for features, not about getting security	1415	it, as major browser developers care only for features, not about getting
1418	right).	1416	security right).
		1417
		1418
		1419	=head1 INTEROPERABILITY WITH OTHER MODULES
		1420
		1421	C<JSON::XS> uses the L<Types::Serialiser> module to provide boolean
		1422	constants. That means that the JSON true and false values will be
		1423	comaptible to true and false values of iother modules that do the same,
		1424	such as L<JSON::PP> and L<CBOR::XS>.
1419		1425
1420		1426
1421	=head1 THREADS	1427	=head1 THREADS
1422		1428
1423	This module is I<not> guaranteed to be thread safe and there are no	1429	This module is I<not> guaranteed to be thread safe and there are no
…		…
1426	process simulations - use fork, it's I<much> faster, cheaper, better).	1432	process simulations - use fork, it's I<much> faster, cheaper, better).
1427		1433
1428	(It might actually work, but you have been warned).	1434	(It might actually work, but you have been warned).
1429		1435
1430		1436
		1437	=head1 THE PERILS OF SETLOCALE
		1438
		1439	Sometimes people avoid the Perl locale support and directly call the
		1440	system's setlocale function with C<LC_ALL>.
		1441
		1442	This breaks both perl and modules such as JSON::XS, as stringification of
		1443	numbers no longer works correctly (e.g. C<$x = 0.1; print "$x"+1> might
		1444	print C<1>, and JSON::XS might output illegal JSON as JSON::XS relies on
		1445	perl to stringify numbers).
		1446
		1447	The solution is simple: don't call C<setlocale>, or use it for only those
		1448	categories you need, such as C<LC_MESSAGES> or C<LC_CTYPE>.
		1449
		1450	If you need C<LC_NUMERIC>, you should enable it only around the code that
		1451	actually needs it (avoiding stringification of numbers), and restore it
		1452	afterwards.
		1453
		1454
1431	=head1 BUGS	1455	=head1 BUGS
1432		1456
1433	While the goal of this module is to be correct, that unfortunately does	1457	While the goal of this module is to be correct, that unfortunately does
1434	not mean it's bug-free, only that I think its design is bug-free. If you	1458	not mean it's bug-free, only that I think its design is bug-free. If you
1435	keep reporting bugs they will be fixed swiftly, though.	1459	keep reporting bugs they will be fixed swiftly, though.
…		…
1437	Please refrain from using rt.cpan.org or any other bug reporting	1461	Please refrain from using rt.cpan.org or any other bug reporting
1438	service. I put the contact address into my modules for a reason.	1462	service. I put the contact address into my modules for a reason.
1439		1463
1440	=cut	1464	=cut
1441		1465
1442	our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" };	1466	BEGIN {
1443	our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" };	1467	*true = \$Types::Serialiser::true;
		1468	*true = \&Types::Serialiser::true;
		1469	*false = \$Types::Serialiser::false;
		1470	*false = \&Types::Serialiser::false;
		1471	*is_bool = \&Types::Serialiser::is_bool;
1444		1472
1445	sub true() { $true }	1473	JSON::XS::Boolean:: = Types::Serialiser::Boolean::;
1446	sub false() { $false }
1447
1448	sub is_bool($) {
1449	UNIVERSAL::isa $_[0], "JSON::XS::Boolean"
1450	# or UNIVERSAL::isa $_[0], "JSON::Literal"
1451	}	1474	}
1452		1475
1453	XSLoader::load "JSON::XS", $VERSION;	1476	XSLoader::load "JSON::XS", $VERSION;
1454
1455	package JSON::XS::Boolean;
1456
1457	use overload
1458	"0+" => sub { ${$_[0]} },
1459	"++" => sub { $_[0] = ${$_[0]} + 1 },
1460	"--" => sub { $_[0] = ${$_[0]} - 1 },
1461	fallback => 1;
1462
1463	1;
1464		1477
1465	=head1 SEE ALSO	1478	=head1 SEE ALSO
1466		1479
1467	The F<json_xs> command line utility for quick experiments.	1480	The F<json_xs> command line utility for quick experiments.
1468		1481
…		…
1471	Marc Lehmann <schmorp@schmorp.de>	1484	Marc Lehmann <schmorp@schmorp.de>
1472	http://home.schmorp.de/	1485	http://home.schmorp.de/
1473		1486
1474	=cut	1487	=cut
1475		1488
		1489	1
		1490

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Comparing JSON-XS/XS.pm (file contents): Revision 1.115 by root, Tue Feb 17 23:29:38 2009 UTC vs. Revision 1.144 by root, Mon Oct 28 23:19:54 2013 UTC

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Comparing JSON-XS/XS.pm (file contents):
Revision 1.115 by root, Tue Feb 17 23:29:38 2009 UTC vs.
Revision 1.144 by root, Mon Oct 28 23:19:54 2013 UTC