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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.9 by root, Fri Mar 23 16:00:19 2007 UTC vs.
Revision 1.22 by root, Sun Mar 25 02:37:00 2007 UTC

…		…
3	JSON::XS - JSON serialising/deserialising, done correctly and fast	3	JSON::XS - JSON serialising/deserialising, done correctly and fast
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use JSON::XS;	7	use JSON::XS;
		8
		9	# exported functions, they croak on error
		10	# and expect/generate UTF-8
		11
		12	$utf8_encoded_json_text = to_json $perl_hash_or_arrayref;
		13	$perl_hash_or_arrayref = from_json $utf8_encoded_json_text;
		14
		15	# objToJson and jsonToObj aliases to to_json and from_json
		16	# are exported for compatibility to the JSON module,
		17	# but should not be used in new code.
		18
		19	# OO-interface
		20
		21	$coder = JSON::XS->new->ascii->pretty->allow_nonref;
		22	$pretty_printed_unencoded = $coder->encode ($perl_scalar);
		23	$perl_scalar = $coder->decode ($unicode_json_text);
8		24
9	=head1 DESCRIPTION	25	=head1 DESCRIPTION
10		26
11	This module converts Perl data structures to JSON and vice versa. Its	27	This module converts Perl data structures to JSON and vice versa. Its
12	primary goal is to be I<correct> and its secondary goal is to be	28	primary goal is to be I<correct> and its secondary goal is to be
…		…
18	their maintainers are unresponsive, gone missing, or not listening to bug	34	their maintainers are unresponsive, gone missing, or not listening to bug
19	reports for other reasons.	35	reports for other reasons.
20		36
21	See COMPARISON, below, for a comparison to some other JSON modules.	37	See COMPARISON, below, for a comparison to some other JSON modules.
22		38
		39	See MAPPING, below, on how JSON::XS maps perl values to JSON values and
		40	vice versa.
		41
23	=head2 FEATURES	42	=head2 FEATURES
24		43
25	=over 4	44	=over 4
26		45
27	=item * correct handling of unicode issues	46	=item * correct unicode handling
28		47
29	This module knows how to handle Unicode, and even documents how it does so.	48	This module knows how to handle Unicode, and even documents how and when
		49	it does so.
30		50
31	=item * round-trip integrity	51	=item * round-trip integrity
32		52
33	When you serialise a perl data structure using only datatypes supported	53	When you serialise a perl data structure using only datatypes supported
34	by JSON, the deserialised data structure is identical on the Perl level.	54	by JSON, the deserialised data structure is identical on the Perl level.
35	(e.g. the string "2.0" doesn't suddenly become "2").	55	(e.g. the string "2.0" doesn't suddenly become "2" just because it looks
		56	like a number).
36		57
37	=item * strict checking of JSON correctness	58	=item * strict checking of JSON correctness
38		59
39	There is no guessing, no generating of illegal JSON strings by default,	60	There is no guessing, no generating of illegal JSON texts by default,
40	and only JSON is accepted as input (the latter is a security feature).	61	and only JSON is accepted as input by default (the latter is a security
		62	feature).
41		63
42	=item * fast	64	=item * fast
43		65
44	compared to other JSON modules, this module compares favourably.	66	Compared to other JSON modules, this module compares favourably in terms
		67	of speed, too.
45		68
46	=item * simple to use	69	=item * simple to use
47		70
48	This module has both a simple functional interface as well as an OO	71	This module has both a simple functional interface as well as an OO
49	interface.	72	interface.
50		73
51	=item * reasonably versatile output formats	74	=item * reasonably versatile output formats
52		75
53	You can choose between the most compact format possible, a pure-ascii	76	You can choose between the most compact guarenteed single-line format
54	format, or a pretty-printed format. Or you can combine those features in	77	possible (nice for simple line-based protocols), a pure-ascii format
55	whatever way you like.	78	(for when your transport is not 8-bit clean, still supports the whole
		79	unicode range), or a pretty-printed format (for when you want to read that
		80	stuff). Or you can combine those features in whatever way you like.
56		81
57	=back	82	=back
58		83
59	=cut	84	=cut
60		85
61	package JSON::XS;	86	package JSON::XS;
62		87
		88	use strict;
		89
63	BEGIN {	90	BEGIN {
64	$VERSION = '0.3';	91	our $VERSION = '0.8';
65	@ISA = qw(Exporter);	92	our @ISA = qw(Exporter);
66		93
67	@EXPORT = qw(to_json from_json);	94	our @EXPORT = qw(to_json from_json objToJson jsonToObj);
68	require Exporter;	95	require Exporter;
69		96
70	require XSLoader;	97	require XSLoader;
71	XSLoader::load JSON::XS::, $VERSION;	98	XSLoader::load JSON::XS::, $VERSION;
72	}	99	}
…		…
76	The following convinience methods are provided by this module. They are	103	The following convinience methods are provided by this module. They are
77	exported by default:	104	exported by default:
78		105
79	=over 4	106	=over 4
80		107
81	=item $json_string = to_json $perl_scalar	108	=item $json_text = to_json $perl_scalar
82		109
83	Converts the given Perl data structure (a simple scalar or a reference to	110	Converts the given Perl data structure (a simple scalar or a reference to
84	a hash or array) to a UTF-8 encoded, binary string (that is, the string contains	111	a hash or array) to a UTF-8 encoded, binary string (that is, the string contains
85	octets only). Croaks on error.	112	octets only). Croaks on error.
86		113
87	This function call is functionally identical to C<< JSON::XS->new->utf8	114	This function call is functionally identical to:
88	(1)->encode ($perl_scalar) >>.
89		115
		116	$json_text = JSON::XS->new->utf8->encode ($perl_scalar)
		117
		118	except being faster.
		119
90	=item $perl_scalar = from_json $json_string	120	=item $perl_scalar = from_json $json_text
91		121
92	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to	122	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to
93	parse that as an UTF-8 encoded JSON string, returning the resulting simple	123	parse that as an UTF-8 encoded JSON text, returning the resulting simple
94	scalar or reference. Croaks on error.	124	scalar or reference. Croaks on error.
95		125
96	This function call is functionally identical to C<< JSON::XS->new->utf8	126	This function call is functionally identical to:
97	(1)->decode ($json_string) >>.	127
		128	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)
		129
		130	except being faster.
98		131
99	=back	132	=back
100		133
101	=head1 OBJECT-ORIENTED INTERFACE	134	=head1 OBJECT-ORIENTED INTERFACE
102		135
…		…
111	strings. All boolean flags described below are by default I<disabled>.	144	strings. All boolean flags described below are by default I<disabled>.
112		145
113	The mutators for flags all return the JSON object again and thus calls can	146	The mutators for flags all return the JSON object again and thus calls can
114	be chained:	147	be chained:
115		148
116	my $json = JSON::XS->new->utf8(1)->space_after(1)->encode ({a => [1,2]})	149	my $json = JSON::XS->new->utf8->space_after->encode ({a => [1,2]})
117	=> {"a": [1, 2]}	150	=> {"a": [1, 2]}
118		151
119	=item $json = $json->ascii ([$enable])	152	=item $json = $json->ascii ([$enable])
120		153
121	If C<$enable> is true (or missing), then the C<encode> method will	154	If C<$enable> is true (or missing), then the C<encode> method will not
122	not generate characters outside the code range C<0..127>. Any unicode	155	generate characters outside the code range C<0..127> (which is ASCII). Any
123	characters outside that range will be escaped using either a single	156	unicode characters outside that range will be escaped using either a
124	\uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, as per	157	single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence,
125	RFC4627.	158	as per RFC4627.
126		159
127	If C<$enable> is false, then the C<encode> method will not escape Unicode	160	If C<$enable> is false, then the C<encode> method will not escape Unicode
128	characters unless necessary.	161	characters unless required by the JSON syntax. This results in a faster
		162	and more compact format.
129		163
130	JSON::XS->new->ascii (1)->encode (chr 0x10401)	164	JSON::XS->new->ascii (1)->encode ([chr 0x10401])
131	=> \ud801\udc01	165	=> ["\ud801\udc01"]
132		166
133	=item $json = $json->utf8 ([$enable])	167	=item $json = $json->utf8 ([$enable])
134		168
135	If C<$enable> is true (or missing), then the C<encode> method will encode	169	If C<$enable> is true (or missing), then the C<encode> method will encode
136	the JSON string into UTF-8, as required by many protocols, while the	170	the JSON result into UTF-8, as required by many protocols, while the
137	C<decode> method expects to be handled an UTF-8-encoded string. Please	171	C<decode> method expects to be handled an UTF-8-encoded string. Please
138	note that UTF-8-encoded strings do not contain any characters outside the	172	note that UTF-8-encoded strings do not contain any characters outside the
139	range C<0..255>, they are thus useful for bytewise/binary I/O.	173	range C<0..255>, they are thus useful for bytewise/binary I/O. In future
		174	versions, enabling this option might enable autodetection of the UTF-16
		175	and UTF-32 encoding families, as described in RFC4627.
140		176
141	If C<$enable> is false, then the C<encode> method will return the JSON	177	If C<$enable> is false, then the C<encode> method will return the JSON
142	string as a (non-encoded) unicode string, while C<decode> expects thus a	178	string as a (non-encoded) unicode string, while C<decode> expects thus a
143	unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs	179	unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs
144	to be done yourself, e.g. using the Encode module.	180	to be done yourself, e.g. using the Encode module.
145		181
		182	Example, output UTF-16BE-encoded JSON:
		183
		184	use Encode;
		185	$jsontext = encode "UTF-16BE", JSON::XS->new->encode ($object);
		186
		187	Example, decode UTF-32LE-encoded JSON:
		188
		189	use Encode;
		190	$object = JSON::XS->new->decode (decode "UTF-32LE", $jsontext);
		191
146	=item $json = $json->pretty ([$enable])	192	=item $json = $json->pretty ([$enable])
147		193
148	This enables (or disables) all of the C<indent>, C<space_before> and	194	This enables (or disables) all of the C<indent>, C<space_before> and
149	C<space_after> (and in the future possibly more) flags in one call to	195	C<space_after> (and in the future possibly more) flags in one call to
150	generate the most readable (or most compact) form possible.	196	generate the most readable (or most compact) form possible.
		197
		198	Example, pretty-print some simple structure:
151		199
152	my $json = JSON::XS->new->pretty(1)->encode ({a => [1,2]})	200	my $json = JSON::XS->new->pretty(1)->encode ({a => [1,2]})
153	=>	201	=>
154	{	202	{
155	"a" : [	203	"a" : [
…		…
163	If C<$enable> is true (or missing), then the C<encode> method will use a multiline	211	If C<$enable> is true (or missing), then the C<encode> method will use a multiline
164	format as output, putting every array member or object/hash key-value pair	212	format as output, putting every array member or object/hash key-value pair
165	into its own line, identing them properly.	213	into its own line, identing them properly.
166		214
167	If C<$enable> is false, no newlines or indenting will be produced, and the	215	If C<$enable> is false, no newlines or indenting will be produced, and the
168	resulting JSON strings is guarenteed not to contain any C<newlines>.	216	resulting JSON text is guarenteed not to contain any C<newlines>.
169		217
170	This setting has no effect when decoding JSON strings.	218	This setting has no effect when decoding JSON texts.
171		219
172	=item $json = $json->space_before ([$enable])	220	=item $json = $json->space_before ([$enable])
173		221
174	If C<$enable> is true (or missing), then the C<encode> method will add an extra	222	If C<$enable> is true (or missing), then the C<encode> method will add an extra
175	optional space before the C<:> separating keys from values in JSON objects.	223	optional space before the C<:> separating keys from values in JSON objects.
176		224
177	If C<$enable> is false, then the C<encode> method will not add any extra	225	If C<$enable> is false, then the C<encode> method will not add any extra
178	space at those places.	226	space at those places.
179		227
180	This setting has no effect when decoding JSON strings. You will also most	228	This setting has no effect when decoding JSON texts. You will also
181	likely combine this setting with C<space_after>.	229	most likely combine this setting with C<space_after>.
		230
		231	Example, space_before enabled, space_after and indent disabled:
		232
		233	{"key" :"value"}
182		234
183	=item $json = $json->space_after ([$enable])	235	=item $json = $json->space_after ([$enable])
184		236
185	If C<$enable> is true (or missing), then the C<encode> method will add an extra	237	If C<$enable> is true (or missing), then the C<encode> method will add an extra
186	optional space after the C<:> separating keys from values in JSON objects	238	optional space after the C<:> separating keys from values in JSON objects
…		…
188	members.	240	members.
189		241
190	If C<$enable> is false, then the C<encode> method will not add any extra	242	If C<$enable> is false, then the C<encode> method will not add any extra
191	space at those places.	243	space at those places.
192		244
193	This setting has no effect when decoding JSON strings.	245	This setting has no effect when decoding JSON texts.
		246
		247	Example, space_before and indent disabled, space_after enabled:
		248
		249	{"key": "value"}
194		250
195	=item $json = $json->canonical ([$enable])	251	=item $json = $json->canonical ([$enable])
196		252
197	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects	253	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects
198	by sorting their keys. This is adding a comparatively high overhead.	254	by sorting their keys. This is adding a comparatively high overhead.
…		…
200	If C<$enable> is false, then the C<encode> method will output key-value	256	If C<$enable> is false, then the C<encode> method will output key-value
201	pairs in the order Perl stores them (which will likely change between runs	257	pairs in the order Perl stores them (which will likely change between runs
202	of the same script).	258	of the same script).
203		259
204	This option is useful if you want the same data structure to be encoded as	260	This option is useful if you want the same data structure to be encoded as
205	the same JSON string (given the same overall settings). If it is disabled,	261	the same JSON text (given the same overall settings). If it is disabled,
206	the same hash migh be encoded differently even if contains the same data,	262	the same hash migh be encoded differently even if contains the same data,
207	as key-value pairs have no inherent ordering in Perl.	263	as key-value pairs have no inherent ordering in Perl.
208		264
209	This setting has no effect when decoding JSON strings.	265	This setting has no effect when decoding JSON texts.
210		266
211	=item $json = $json->allow_nonref ([$enable])	267	=item $json = $json->allow_nonref ([$enable])
212		268
213	If C<$enable> is true (or missing), then the C<encode> method can convert a	269	If C<$enable> is true (or missing), then the C<encode> method can convert a
214	non-reference into its corresponding string, number or null JSON value,	270	non-reference into its corresponding string, number or null JSON value,
215	which is an extension to RFC4627. Likewise, C<decode> will accept those JSON	271	which is an extension to RFC4627. Likewise, C<decode> will accept those JSON
216	values instead of croaking.	272	values instead of croaking.
217		273
218	If C<$enable> is false, then the C<encode> method will croak if it isn't	274	If C<$enable> is false, then the C<encode> method will croak if it isn't
219	passed an arrayref or hashref, as JSON strings must either be an object	275	passed an arrayref or hashref, as JSON texts must either be an object
220	or array. Likewise, C<decode> will croak if given something that is not a	276	or array. Likewise, C<decode> will croak if given something that is not a
221	JSON object or array.	277	JSON object or array.
		278
		279	Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,
		280	resulting in an invalid JSON text:
		281
		282	JSON::XS->new->allow_nonref->encode ("Hello, World!")
		283	=> "Hello, World!"
222		284
223	=item $json = $json->shrink ([$enable])	285	=item $json = $json->shrink ([$enable])
224		286
225	Perl usually over-allocates memory a bit when allocating space for	287	Perl usually over-allocates memory a bit when allocating space for
226	strings. This flag optionally resizes strings generated by either	288	strings. This flag optionally resizes strings generated by either
227	C<encode> or C<decode> to their minimum size possible. This can save	289	C<encode> or C<decode> to their minimum size possible. This can save
228	memory when your JSON strings are either very very long or you have many	290	memory when your JSON texts are either very very long or you have many
229	short strings. It will also try to downgrade any strings to octet-form	291	short strings. It will also try to downgrade any strings to octet-form
230	if possible: perl stores strings internally either in an encoding called	292	if possible: perl stores strings internally either in an encoding called
231	UTF-X or in octet-form. The latter cannot store everything but uses less	293	UTF-X or in octet-form. The latter cannot store everything but uses less
232	space in general.	294	space in general.
233		295
…		…
239		301
240	In the future, this setting might control other things, such as converting	302	In the future, this setting might control other things, such as converting
241	strings that look like integers or floats into integers or floats	303	strings that look like integers or floats into integers or floats
242	internally (there is no difference on the Perl level), saving space.	304	internally (there is no difference on the Perl level), saving space.
243		305
244	=item $json_string = $json->encode ($perl_scalar)	306	=item $json_text = $json->encode ($perl_scalar)
245		307
246	Converts the given Perl data structure (a simple scalar or a reference	308	Converts the given Perl data structure (a simple scalar or a reference
247	to a hash or array) to its JSON representation. Simple scalars will be	309	to a hash or array) to its JSON representation. Simple scalars will be
248	converted into JSON string or number sequences, while references to arrays	310	converted into JSON string or number sequences, while references to arrays
249	become JSON arrays and references to hashes become JSON objects. Undefined	311	become JSON arrays and references to hashes become JSON objects. Undefined
250	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>	312	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>
251	nor C<false> values will be generated.	313	nor C<false> values will be generated.
252		314
253	=item $perl_scalar = $json->decode ($json_string)	315	=item $perl_scalar = $json->decode ($json_text)
254		316
255	The opposite of C<encode>: expects a JSON string and tries to parse it,	317	The opposite of C<encode>: expects a JSON text and tries to parse it,
256	returning the resulting simple scalar or reference. Croaks on error.	318	returning the resulting simple scalar or reference. Croaks on error.
257		319
258	JSON numbers and strings become simple Perl scalars. JSON arrays become	320	JSON numbers and strings become simple Perl scalars. JSON arrays become
259	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes	321	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes
260	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.	322	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.
		323
		324	=back
		325
		326	=head1 MAPPING
		327
		328	This section describes how JSON::XS maps Perl values to JSON values and
		329	vice versa. These mappings are designed to "do the right thing" in most
		330	circumstances automatically, preserving round-tripping characteristics
		331	(what you put in comes out as something equivalent).
		332
		333	For the more enlightened: note that in the following descriptions,
		334	lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl>
		335	refers to the abstract Perl language itself.
		336
		337	=head2 JSON -> PERL
		338
		339	=over 4
		340
		341	=item object
		342
		343	A JSON object becomes a reference to a hash in Perl. No ordering of object
		344	keys is preserved (JSON does not preserver object key ordering itself).
		345
		346	=item array
		347
		348	A JSON array becomes a reference to an array in Perl.
		349
		350	=item string
		351
		352	A JSON string becomes a string scalar in Perl - Unicode codepoints in JSON
		353	are represented by the same codepoints in the Perl string, so no manual
		354	decoding is necessary.
		355
		356	=item number
		357
		358	A JSON number becomes either an integer or numeric (floating point)
		359	scalar in perl, depending on its range and any fractional parts. On the
		360	Perl level, there is no difference between those as Perl handles all the
		361	conversion details, but an integer may take slightly less memory and might
		362	represent more values exactly than (floating point) numbers.
		363
		364	=item true, false
		365
		366	These JSON atoms become C<0>, C<1>, respectively. Information is lost in
		367	this process. Future versions might represent those values differently,
		368	but they will be guarenteed to act like these integers would normally in
		369	Perl.
		370
		371	=item null
		372
		373	A JSON null atom becomes C<undef> in Perl.
		374
		375	=back
		376
		377	=head2 PERL -> JSON
		378
		379	The mapping from Perl to JSON is slightly more difficult, as Perl is a
		380	truly typeless language, so we can only guess which JSON type is meant by
		381	a Perl value.
		382
		383	=over 4
		384
		385	=item hash references
		386
		387	Perl hash references become JSON objects. As there is no inherent ordering
		388	in hash keys, they will usually be encoded in a pseudo-random order that
		389	can change between runs of the same program but stays generally the same
		390	within a single run of a program. JSON::XS can optionally sort the hash
		391	keys (determined by the I<canonical> flag), so the same datastructure
		392	will serialise to the same JSON text (given same settings and version of
		393	JSON::XS), but this incurs a runtime overhead.
		394
		395	=item array references
		396
		397	Perl array references become JSON arrays.
		398
		399	=item blessed objects
		400
		401	Blessed objects are not allowed. JSON::XS currently tries to encode their
		402	underlying representation (hash- or arrayref), but this behaviour might
		403	change in future versions.
		404
		405	=item simple scalars
		406
		407	Simple Perl scalars (any scalar that is not a reference) are the most
		408	difficult objects to encode: JSON::XS will encode undefined scalars as
		409	JSON null value, scalars that have last been used in a string context
		410	before encoding as JSON strings and anything else as number value:
		411
		412	# dump as number
		413	to_json [2] # yields [2]
		414	to_json [-3.0e17] # yields [-3e+17]
		415	my $value = 5; to_json [$value] # yields [5]
		416
		417	# used as string, so dump as string
		418	print $value;
		419	to_json [$value] # yields ["5"]
		420
		421	# undef becomes null
		422	to_json [undef] # yields [null]
		423
		424	You can force the type to be a string by stringifying it:
		425
		426	my $x = 3.1; # some variable containing a number
		427	"$x"; # stringified
		428	$x .= ""; # another, more awkward way to stringify
		429	print $x; # perl does it for you, too, quite often
		430
		431	You can force the type to be a number by numifying it:
		432
		433	my $x = "3"; # some variable containing a string
		434	$x += 0; # numify it, ensuring it will be dumped as a number
		435	$x *= 1; # same thing, the choise is yours.
		436
		437	You can not currently output JSON booleans or force the type in other,
		438	less obscure, ways. Tell me if you need this capability.
		439
		440	=item circular data structures
		441
		442	Those will be encoded until memory or stackspace runs out.
261		443
262	=back	444	=back
263		445
264	=head1 COMPARISON	446	=head1 COMPARISON
265		447
…		…
293		475
294	Has problems handling many Perl values (e.g. regex results and other magic	476	Has problems handling many Perl values (e.g. regex results and other magic
295	values will make it croak).	477	values will make it croak).
296		478
297	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>	479	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>
298	which is not a valid JSON string.	480	which is not a valid JSON text.
299		481
300	Unmaintained (maintainer unresponsive for many months, bugs are not	482	Unmaintained (maintainer unresponsive for many months, bugs are not
301	getting fixed).	483	getting fixed).
302		484
303	=item JSON::Syck 0.21	485	=item JSON::Syck 0.21
…		…
305	Very buggy (often crashes).	487	Very buggy (often crashes).
306		488
307	Very inflexible (no human-readable format supported, format pretty much	489	Very inflexible (no human-readable format supported, format pretty much
308	undocumented. I need at least a format for easy reading by humans and a	490	undocumented. I need at least a format for easy reading by humans and a
309	single-line compact format for use in a protocol, and preferably a way to	491	single-line compact format for use in a protocol, and preferably a way to
310	generate ASCII-only JSON strings).	492	generate ASCII-only JSON texts).
311		493
312	Completely broken (and confusingly documented) Unicode handling (unicode	494	Completely broken (and confusingly documented) Unicode handling (unicode
313	escapes are not working properly, you need to set ImplicitUnicode to	495	escapes are not working properly, you need to set ImplicitUnicode to
314	I<different> values on en- and decoding to get symmetric behaviour).	496	I<different> values on en- and decoding to get symmetric behaviour).
315		497
…		…
338		520
339	Very inflexible.	521	Very inflexible.
340		522
341	No roundtripping.	523	No roundtripping.
342		524
343	Does not generate valid JSON (key strings are often unquoted, empty keys	525	Does not generate valid JSON texts (key strings are often unquoted, empty keys
344	result in nothing being output)	526	result in nothing being output)
345		527
346	Does not check input for validity.	528	Does not check input for validity.
347		529
348	=back	530	=back
…		…
352	It seems that JSON::XS is surprisingly fast, as shown in the following	534	It seems that JSON::XS is surprisingly fast, as shown in the following
353	tables. They have been generated with the help of the C<eg/bench> program	535	tables. They have been generated with the help of the C<eg/bench> program
354	in the JSON::XS distribution, to make it easy to compare on your own	536	in the JSON::XS distribution, to make it easy to compare on your own
355	system.	537	system.
356		538
357	First is a comparison between various modules using a very simple JSON	539	First comes a comparison between various modules using a very short JSON
		540	string:
		541
		542	{"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null}
		543
358	string, showing the number of encodes/decodes per second (JSON::XS is	544	It shows the number of encodes/decodes per second (JSON::XS uses the
359	the functional interface, while JSON::XS/2 is the OO interface with	545	functional interface, while JSON::XS/2 uses the OO interface with
360	pretty-printing and hashkey sorting enabled).	546	pretty-printing and hashkey sorting enabled). Higher is better:
361		547
362	module \| encode \| decode \|	548	module \| encode \| decode \|
363	-----------\|------------\|------------\|	549	-----------\|------------\|------------\|
364	JSON \| 14006 \| 6820 \|	550	JSON \| 11488.516 \| 7823.035 \|
365	JSON::DWIW \| 200937 \| 120386 \|	551	JSON::DWIW \| 94708.054 \| 129094.260 \|
366	JSON::PC \| 85065 \| 129366 \|	552	JSON::PC \| 63884.157 \| 128528.212 \|
367	JSON::Syck \| 59898 \| 44232 \|	553	JSON::Syck \| 34898.677 \| 42096.911 \|
368	JSON::XS \| 1171478 \| 342435 \|	554	JSON::XS \| 654027.064 \| 396423.669 \|
369	JSON::XS/2 \| 730760 \| 328714 \|	555	JSON::XS/2 \| 371564.190 \| 371725.613 \|
370	-----------+------------+------------+	556	-----------+------------+------------+
371		557
372	That is, JSON::XS is 6 times faster than than JSON::DWIW and about 80	558	That is, JSON::XS is more than six times faster than JSON::DWIW on
		559	encoding, more than three times faster on decoding, and about thirty times
373	times faster than JSON, even with pretty-printing and key sorting.	560	faster than JSON, even with pretty-printing and key sorting.
374		561
375	Using a longer test string (roughly 8KB, generated from Yahoo! Locals	562	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
376	search API (http://nanoref.com/yahooapis/mgPdGg):	563	search API (http://nanoref.com/yahooapis/mgPdGg):
377		564
378	module \| encode \| decode \|	565	module \| encode \| decode \|
379	-----------\|------------\|------------\|	566	-----------\|------------\|------------\|
380	JSON \| 673 \| 38 \|	567	JSON \| 273.023 \| 44.674 \|
381	JSON::DWIW \| 5271 \| 770 \|	568	JSON::DWIW \| 1089.383 \| 1145.704 \|
382	JSON::PC \| 9901 \| 2491 \|	569	JSON::PC \| 3097.419 \| 2393.921 \|
383	JSON::Syck \| 2360 \| 786 \|	570	JSON::Syck \| 514.060 \| 843.053 \|
384	JSON::XS \| 37398 \| 3202 \|	571	JSON::XS \| 6479.668 \| 3636.364 \|
385	JSON::XS/2 \| 13765 \| 3153 \|	572	JSON::XS/2 \| 3774.221 \| 3599.124 \|
386	-----------+------------+------------+	573	-----------+------------+------------+
387		574
388	Again, JSON::XS leads by far in the encoding case, while still beating	575	Again, JSON::XS leads by far.
389	every other module in the decoding case.
390		576
391	Last example is an almost 8MB large hash with many large binary values	577	On large strings containing lots of high unicode characters, some modules
392	(PNG files), resulting in a lot of escaping:	578	(such as JSON::PC) seem to decode faster than JSON::XS, but the result
		579	will be broken due to missing (or wrong) unicode handling. Others refuse
		580	to decode or encode properly, so it was impossible to prepare a fair
		581	comparison table for that case.
		582
		583	=head1 RESOURCE LIMITS
		584
		585	JSON::XS does not impose any limits on the size of JSON texts or Perl
		586	values they represent - if your machine can handle it, JSON::XS will
		587	encode or decode it. Future versions might optionally impose structure
		588	depth and memory use resource limits.
393		589
394	=head1 BUGS	590	=head1 BUGS
395		591
396	While the goal of this module is to be correct, that unfortunately does	592	While the goal of this module is to be correct, that unfortunately does
397	not mean its bug-free, only that I think its design is bug-free. It is	593	not mean its bug-free, only that I think its design is bug-free. It is

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Comparing JSON-XS/XS.pm (file contents): Revision 1.9 by root, Fri Mar 23 16:00:19 2007 UTC vs. Revision 1.22 by root, Sun Mar 25 02:37:00 2007 UTC

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Comparing JSON-XS/XS.pm (file contents):
Revision 1.9 by root, Fri Mar 23 16:00:19 2007 UTC vs.
Revision 1.22 by root, Sun Mar 25 02:37:00 2007 UTC