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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.8 by root, Fri Mar 23 15:57:18 2007 UTC vs.
Revision 1.21 by root, Sun Mar 25 02:32:40 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, croak on error
		10
		11	$utf8_encoded_json_text = to_json $perl_hash_or_arrayref;
		12	$perl_hash_or_arrayref = from_json $utf8_encoded_json_text;
		13
		14	# objToJson and jsonToObj are exported for JSON
		15	# compatibility, but should not be used in new code.
		16
		17	# oo-interface
		18
		19	$coder = JSON::XS->new->ascii->pretty->allow_nonref;
		20	$pretty_printed_unencoded = $coder->encode ($perl_scalar);
		21	$perl_scalar = $coder->decode ($unicode_json_text);
8		22
9	=head1 DESCRIPTION	23	=head1 DESCRIPTION
10		24
11	This module converts Perl data structures to JSON and vice versa. Its	25	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	26	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	32	their maintainers are unresponsive, gone missing, or not listening to bug
19	reports for other reasons.	33	reports for other reasons.
20		34
21	See COMPARISON, below, for a comparison to some other JSON modules.	35	See COMPARISON, below, for a comparison to some other JSON modules.
22		36
		37	See MAPPING, below, on how JSON::XS maps perl values to JSON values and
		38	vice versa.
		39
23	=head2 FEATURES	40	=head2 FEATURES
24		41
25	=over 4	42	=over 4
26		43
27	=item * correct handling of unicode issues	44	=item * correct unicode handling
28		45
29	This module knows how to handle Unicode, and even documents how it does so.	46	This module knows how to handle Unicode, and even documents how and when
		47	it does so.
30		48
31	=item * round-trip integrity	49	=item * round-trip integrity
32		50
33	When you serialise a perl data structure using only datatypes supported	51	When you serialise a perl data structure using only datatypes supported
34	by JSON, the deserialised data structure is identical on the Perl level.	52	by JSON, the deserialised data structure is identical on the Perl level.
35	(e.g. the string "2.0" doesn't suddenly become "2").	53	(e.g. the string "2.0" doesn't suddenly become "2" just because it looks
		54	like a number).
36		55
37	=item * strict checking of JSON correctness	56	=item * strict checking of JSON correctness
38		57
39	There is no guessing, no generating of illegal JSON strings by default,	58	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).	59	and only JSON is accepted as input by default (the latter is a security
		60	feature).
41		61
42	=item * fast	62	=item * fast
43		63
44	compared to other JSON modules, this module compares favourably.	64	Compared to other JSON modules, this module compares favourably in terms
		65	of speed, too.
45		66
46	=item * simple to use	67	=item * simple to use
47		68
48	This module has both a simple functional interface as well as an OO	69	This module has both a simple functional interface as well as an OO
49	interface.	70	interface.
50		71
51	=item * reasonably versatile output formats	72	=item * reasonably versatile output formats
52		73
53	You can choose between the most compact format possible, a pure-ascii	74	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	75	possible (nice for simple line-based protocols), a pure-ascii format
55	whatever way you like.	76	(for when your transport is not 8-bit clean, still supports the whole
		77	unicode range), or a pretty-printed format (for when you want to read that
		78	stuff). Or you can combine those features in whatever way you like.
56		79
57	=back	80	=back
58		81
59	=cut	82	=cut
60		83
61	package JSON::XS;	84	package JSON::XS;
62		85
		86	use strict;
		87
63	BEGIN {	88	BEGIN {
64	$VERSION = '0.2';	89	our $VERSION = '0.8';
65	@ISA = qw(Exporter);	90	our @ISA = qw(Exporter);
66		91
67	@EXPORT = qw(to_json from_json);	92	our @EXPORT = qw(to_json from_json objToJson jsonToObj);
68	require Exporter;	93	require Exporter;
69		94
70	require XSLoader;	95	require XSLoader;
71	XSLoader::load JSON::XS::, $VERSION;	96	XSLoader::load JSON::XS::, $VERSION;
72	}	97	}
…		…
76	The following convinience methods are provided by this module. They are	101	The following convinience methods are provided by this module. They are
77	exported by default:	102	exported by default:
78		103
79	=over 4	104	=over 4
80		105
81	=item $json_string = to_json $perl_scalar	106	=item $json_text = to_json $perl_scalar
82		107
83	Converts the given Perl data structure (a simple scalar or a reference to	108	Converts the given Perl data structure (a simple scalar or a reference to
84	a hash or array) to a UTF-8 encoded, binary string (that is, the string contains	109	a hash or array) to a UTF-8 encoded, binary string (that is, the string contains
85	octets only). Croaks on error.	110	octets only). Croaks on error.
86		111
87	This function call is functionally identical to C<< JSON::XS->new->utf8	112	This function call is functionally identical to:
88	(1)->encode ($perl_scalar) >>.
89		113
		114	$json_text = JSON::XS->new->utf8->encode ($perl_scalar)
		115
		116	except being faster.
		117
90	=item $perl_scalar = from_json $json_string	118	=item $perl_scalar = from_json $json_text
91		119
92	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to	120	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to
93	parse that as an UTF-8 encoded JSON string, returning the resulting simple	121	parse that as an UTF-8 encoded JSON text, returning the resulting simple
94	scalar or reference. Croaks on error.	122	scalar or reference. Croaks on error.
95		123
96	This function call is functionally identical to C<< JSON::XS->new->utf8	124	This function call is functionally identical to:
97	(1)->decode ($json_string) >>.	125
		126	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)
		127
		128	except being faster.
98		129
99	=back	130	=back
100		131
101	=head1 OBJECT-ORIENTED INTERFACE	132	=head1 OBJECT-ORIENTED INTERFACE
102		133
…		…
111	strings. All boolean flags described below are by default I<disabled>.	142	strings. All boolean flags described below are by default I<disabled>.
112		143
113	The mutators for flags all return the JSON object again and thus calls can	144	The mutators for flags all return the JSON object again and thus calls can
114	be chained:	145	be chained:
115		146
116	my $json = JSON::XS->new->utf8(1)->space_after(1)->encode ({a => [1,2]})	147	my $json = JSON::XS->new->utf8->space_after->encode ({a => [1,2]})
117	=> {"a": [1, 2]}	148	=> {"a": [1, 2]}
118		149
119	=item $json = $json->ascii ([$enable])	150	=item $json = $json->ascii ([$enable])
120		151
121	If C<$enable> is true (or missing), then the C<encode> method will	152	If C<$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	153	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	154	unicode characters outside that range will be escaped using either a
124	\uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, as per	155	single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence,
125	RFC4627.	156	as per RFC4627.
126		157
127	If C<$enable> is false, then the C<encode> method will not escape Unicode	158	If C<$enable> is false, then the C<encode> method will not escape Unicode
128	characters unless necessary.	159	characters unless required by the JSON syntax. This results in a faster
		160	and more compact format.
129		161
130	JSON::XS->new->ascii (1)->encode (chr 0x10401)	162	JSON::XS->new->ascii (1)->encode ([chr 0x10401])
131	=> \ud801\udc01	163	=> ["\ud801\udc01"]
132		164
133	=item $json = $json->utf8 ([$enable])	165	=item $json = $json->utf8 ([$enable])
134		166
135	If C<$enable> is true (or missing), then the C<encode> method will encode	167	If C<$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	168	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	169	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	170	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.	171	range C<0..255>, they are thus useful for bytewise/binary I/O. In future
		172	versions, enabling this option might enable autodetection of the UTF-16
		173	and UTF-32 encoding families, as described in RFC4627.
140		174
141	If C<$enable> is false, then the C<encode> method will return the JSON	175	If C<$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	176	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	177	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.	178	to be done yourself, e.g. using the Encode module.
145		179
		180	Example, output UTF-16BE-encoded JSON:
		181
		182	use Encode;
		183	$jsontext = encode "UTF-16BE", JSON::XS->new->encode ($object);
		184
		185	Example, decode UTF-32LE-encoded JSON:
		186
		187	use Encode;
		188	$object = JSON::XS->new->decode (decode "UTF-32LE", $jsontext);
		189
146	=item $json = $json->pretty ([$enable])	190	=item $json = $json->pretty ([$enable])
147		191
148	This enables (or disables) all of the C<indent>, C<space_before> and	192	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	193	C<space_after> (and in the future possibly more) flags in one call to
150	generate the most readable (or most compact) form possible.	194	generate the most readable (or most compact) form possible.
		195
		196	Example, pretty-print some simple structure:
151		197
152	my $json = JSON::XS->new->pretty(1)->encode ({a => [1,2]})	198	my $json = JSON::XS->new->pretty(1)->encode ({a => [1,2]})
153	=>	199	=>
154	{	200	{
155	"a" : [	201	"a" : [
…		…
163	If C<$enable> is true (or missing), then the C<encode> method will use a multiline	209	If C<$enable> is true (or missing), then the C<encode> method will use a multiline
164	format as output, putting every array member or object/hash key-value pair	210	format as output, putting every array member or object/hash key-value pair
165	into its own line, identing them properly.	211	into its own line, identing them properly.
166		212
167	If C<$enable> is false, no newlines or indenting will be produced, and the	213	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>.	214	resulting JSON text is guarenteed not to contain any C<newlines>.
169		215
170	This setting has no effect when decoding JSON strings.	216	This setting has no effect when decoding JSON texts.
171		217
172	=item $json = $json->space_before ([$enable])	218	=item $json = $json->space_before ([$enable])
173		219
174	If C<$enable> is true (or missing), then the C<encode> method will add an extra	220	If C<$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.	221	optional space before the C<:> separating keys from values in JSON objects.
176		222
177	If C<$enable> is false, then the C<encode> method will not add any extra	223	If C<$enable> is false, then the C<encode> method will not add any extra
178	space at those places.	224	space at those places.
179		225
180	This setting has no effect when decoding JSON strings. You will also most	226	This setting has no effect when decoding JSON texts. You will also
181	likely combine this setting with C<space_after>.	227	most likely combine this setting with C<space_after>.
		228
		229	Example, space_before enabled, space_after and indent disabled:
		230
		231	{"key" :"value"}
182		232
183	=item $json = $json->space_after ([$enable])	233	=item $json = $json->space_after ([$enable])
184		234
185	If C<$enable> is true (or missing), then the C<encode> method will add an extra	235	If C<$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	236	optional space after the C<:> separating keys from values in JSON objects
…		…
188	members.	238	members.
189		239
190	If C<$enable> is false, then the C<encode> method will not add any extra	240	If C<$enable> is false, then the C<encode> method will not add any extra
191	space at those places.	241	space at those places.
192		242
193	This setting has no effect when decoding JSON strings.	243	This setting has no effect when decoding JSON texts.
		244
		245	Example, space_before and indent disabled, space_after enabled:
		246
		247	{"key": "value"}
194		248
195	=item $json = $json->canonical ([$enable])	249	=item $json = $json->canonical ([$enable])
196		250
197	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects	251	If C<$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.	252	by sorting their keys. This is adding a comparatively high overhead.
…		…
200	If C<$enable> is false, then the C<encode> method will output key-value	254	If C<$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	255	pairs in the order Perl stores them (which will likely change between runs
202	of the same script).	256	of the same script).
203		257
204	This option is useful if you want the same data structure to be encoded as	258	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,	259	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,	260	the same hash migh be encoded differently even if contains the same data,
207	as key-value pairs have no inherent ordering in Perl.	261	as key-value pairs have no inherent ordering in Perl.
208		262
209	This setting has no effect when decoding JSON strings.	263	This setting has no effect when decoding JSON texts.
210		264
211	=item $json = $json->allow_nonref ([$enable])	265	=item $json = $json->allow_nonref ([$enable])
212		266
213	If C<$enable> is true (or missing), then the C<encode> method can convert a	267	If C<$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,	268	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	269	which is an extension to RFC4627. Likewise, C<decode> will accept those JSON
216	values instead of croaking.	270	values instead of croaking.
217		271
218	If C<$enable> is false, then the C<encode> method will croak if it isn't	272	If C<$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	273	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	274	or array. Likewise, C<decode> will croak if given something that is not a
221	JSON object or array.	275	JSON object or array.
		276
		277	Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,
		278	resulting in an invalid JSON text:
		279
		280	JSON::XS->new->allow_nonref->encode ("Hello, World!")
		281	=> "Hello, World!"
222		282
223	=item $json = $json->shrink ([$enable])	283	=item $json = $json->shrink ([$enable])
224		284
225	Perl usually over-allocates memory a bit when allocating space for	285	Perl usually over-allocates memory a bit when allocating space for
226	strings. This flag optionally resizes strings generated by either	286	strings. This flag optionally resizes strings generated by either
227	C<encode> or C<decode> to their minimum size possible. This can save	287	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	288	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	289	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	290	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	291	UTF-X or in octet-form. The latter cannot store everything but uses less
232	space in general.	292	space in general.
233		293
…		…
239		299
240	In the future, this setting might control other things, such as converting	300	In the future, this setting might control other things, such as converting
241	strings that look like integers or floats into integers or floats	301	strings that look like integers or floats into integers or floats
242	internally (there is no difference on the Perl level), saving space.	302	internally (there is no difference on the Perl level), saving space.
243		303
244	=item $json_string = $json->encode ($perl_scalar)	304	=item $json_text = $json->encode ($perl_scalar)
245		305
246	Converts the given Perl data structure (a simple scalar or a reference	306	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	307	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	308	converted into JSON string or number sequences, while references to arrays
249	become JSON arrays and references to hashes become JSON objects. Undefined	309	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>	310	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>
251	nor C<false> values will be generated.	311	nor C<false> values will be generated.
252		312
253	=item $perl_scalar = $json->decode ($json_string)	313	=item $perl_scalar = $json->decode ($json_text)
254		314
255	The opposite of C<encode>: expects a JSON string and tries to parse it,	315	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.	316	returning the resulting simple scalar or reference. Croaks on error.
257		317
258	JSON numbers and strings become simple Perl scalars. JSON arrays become	318	JSON numbers and strings become simple Perl scalars. JSON arrays become
259	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes	319	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>.	320	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.
		321
		322	=back
		323
		324	=head1 MAPPING
		325
		326	This section describes how JSON::XS maps Perl values to JSON values and
		327	vice versa. These mappings are designed to "do the right thing" in most
		328	circumstances automatically, preserving round-tripping characteristics
		329	(what you put in comes out as something equivalent).
		330
		331	For the more enlightened: note that in the following descriptions,
		332	lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl>
		333	refers to the abstract Perl language itself.
		334
		335	=head2 JSON -> PERL
		336
		337	=over 4
		338
		339	=item object
		340
		341	A JSON object becomes a reference to a hash in Perl. No ordering of object
		342	keys is preserved (JSON does not preserver object key ordering itself).
		343
		344	=item array
		345
		346	A JSON array becomes a reference to an array in Perl.
		347
		348	=item string
		349
		350	A JSON string becomes a string scalar in Perl - Unicode codepoints in JSON
		351	are represented by the same codepoints in the Perl string, so no manual
		352	decoding is necessary.
		353
		354	=item number
		355
		356	A JSON number becomes either an integer or numeric (floating point)
		357	scalar in perl, depending on its range and any fractional parts. On the
		358	Perl level, there is no difference between those as Perl handles all the
		359	conversion details, but an integer may take slightly less memory and might
		360	represent more values exactly than (floating point) numbers.
		361
		362	=item true, false
		363
		364	These JSON atoms become C<0>, C<1>, respectively. Information is lost in
		365	this process. Future versions might represent those values differently,
		366	but they will be guarenteed to act like these integers would normally in
		367	Perl.
		368
		369	=item null
		370
		371	A JSON null atom becomes C<undef> in Perl.
		372
		373	=back
		374
		375	=head2 PERL -> JSON
		376
		377	The mapping from Perl to JSON is slightly more difficult, as Perl is a
		378	truly typeless language, so we can only guess which JSON type is meant by
		379	a Perl value.
		380
		381	=over 4
		382
		383	=item hash references
		384
		385	Perl hash references become JSON objects. As there is no inherent ordering
		386	in hash keys, they will usually be encoded in a pseudo-random order that
		387	can change between runs of the same program but stays generally the same
		388	within a single run of a program. JSON::XS can optionally sort the hash
		389	keys (determined by the I<canonical> flag), so the same datastructure
		390	will serialise to the same JSON text (given same settings and version of
		391	JSON::XS), but this incurs a runtime overhead.
		392
		393	=item array references
		394
		395	Perl array references become JSON arrays.
		396
		397	=item blessed objects
		398
		399	Blessed objects are not allowed. JSON::XS currently tries to encode their
		400	underlying representation (hash- or arrayref), but this behaviour might
		401	change in future versions.
		402
		403	=item simple scalars
		404
		405	Simple Perl scalars (any scalar that is not a reference) are the most
		406	difficult objects to encode: JSON::XS will encode undefined scalars as
		407	JSON null value, scalars that have last been used in a string context
		408	before encoding as JSON strings and anything else as number value:
		409
		410	# dump as number
		411	to_json [2] # yields [2]
		412	to_json [-3.0e17] # yields [-3e+17]
		413	my $value = 5; to_json [$value] # yields [5]
		414
		415	# used as string, so dump as string
		416	print $value;
		417	to_json [$value] # yields ["5"]
		418
		419	# undef becomes null
		420	to_json [undef] # yields [null]
		421
		422	You can force the type to be a string by stringifying it:
		423
		424	my $x = 3.1; # some variable containing a number
		425	"$x"; # stringified
		426	$x .= ""; # another, more awkward way to stringify
		427	print $x; # perl does it for you, too, quite often
		428
		429	You can force the type to be a number by numifying it:
		430
		431	my $x = "3"; # some variable containing a string
		432	$x += 0; # numify it, ensuring it will be dumped as a number
		433	$x *= 1; # same thing, the choise is yours.
		434
		435	You can not currently output JSON booleans or force the type in other,
		436	less obscure, ways. Tell me if you need this capability.
		437
		438	=item circular data structures
		439
		440	Those will be encoded until memory or stackspace runs out.
261		441
262	=back	442	=back
263		443
264	=head1 COMPARISON	444	=head1 COMPARISON
265		445
…		…
293		473
294	Has problems handling many Perl values (e.g. regex results and other magic	474	Has problems handling many Perl values (e.g. regex results and other magic
295	values will make it croak).	475	values will make it croak).
296		476
297	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>	477	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>
298	which is not a valid JSON string.	478	which is not a valid JSON text.
299		479
300	Unmaintained (maintainer unresponsive for many months, bugs are not	480	Unmaintained (maintainer unresponsive for many months, bugs are not
301	getting fixed).	481	getting fixed).
302		482
303	=item JSON::Syck 0.21	483	=item JSON::Syck 0.21
…		…
305	Very buggy (often crashes).	485	Very buggy (often crashes).
306		486
307	Very inflexible (no human-readable format supported, format pretty much	487	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	488	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	489	single-line compact format for use in a protocol, and preferably a way to
310	generate ASCII-only JSON strings).	490	generate ASCII-only JSON texts).
311		491
312	Completely broken (and confusingly documented) Unicode handling (unicode	492	Completely broken (and confusingly documented) Unicode handling (unicode
313	escapes are not working properly, you need to set ImplicitUnicode to	493	escapes are not working properly, you need to set ImplicitUnicode to
314	I<different> values on en- and decoding to get symmetric behaviour).	494	I<different> values on en- and decoding to get symmetric behaviour).
315		495
…		…
338		518
339	Very inflexible.	519	Very inflexible.
340		520
341	No roundtripping.	521	No roundtripping.
342		522
343	Does not generate valid JSON (key strings are often unquoted, empty keys	523	Does not generate valid JSON texts (key strings are often unquoted, empty keys
344	result in nothing being output)	524	result in nothing being output)
345		525
346	Does not check input for validity.	526	Does not check input for validity.
347		527
348	=back	528	=back
…		…
352	It seems that JSON::XS is surprisingly fast, as shown in the following	532	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	533	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	534	in the JSON::XS distribution, to make it easy to compare on your own
355	system.	535	system.
356		536
357	First is a comparison between various modules using a very simple JSON	537	First comes a comparison between various modules using a very short JSON
		538	string:
		539
		540	{"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null}
		541
358	string, showing the number of encodes/decodes per second (JSON::XS is	542	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	543	functional interface, while JSON::XS/2 uses the OO interface with
360	pretty-printing and hashkey sorting enabled).	544	pretty-printing and hashkey sorting enabled). Higher is better:
361		545
362	module \| encode \| decode \|	546	module \| encode \| decode \|
363	-----------\|------------\|------------\|	547	-----------\|------------\|------------\|
364	JSON \| 14006 \| 6820 \|	548	JSON \| 11488.516 \| 7823.035 \|
365	JSON::DWIW \| 200937 \| 120386 \|	549	JSON::DWIW \| 94708.054 \| 129094.260 \|
366	JSON::PC \| 85065 \| 129366 \|	550	JSON::PC \| 63884.157 \| 128528.212 \|
367	JSON::Syck \| 59898 \| 44232 \|	551	JSON::Syck \| 34898.677 \| 42096.911 \|
368	JSON::XS \| 1171478 \| 342435 \|	552	JSON::XS \| 654027.064 \| 396423.669 \|
369	JSON::XS/2 \| 730760 \| 328714 \|	553	JSON::XS/2 \| 371564.190 \| 371725.613 \|
370	-----------+------------+------------+	554	-----------+------------+------------+
371		555
372	That is, JSON::XS is 6 times faster than than JSON::DWIW and about 80	556	That is, JSON::XS is more than six times faster than JSON::DWIW on
		557	encoding, more than three times faster on decoding, and about thirty times
373	times faster than JSON, even with pretty-printing and key sorting.	558	faster than JSON, even with pretty-printing and key sorting.
374		559
375	Using a longer test string (roughly 8KB, generated from Yahoo! Locals	560	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
376	search API (http://nanoref.com/yahooapis/mgPdGg):	561	search API (http://nanoref.com/yahooapis/mgPdGg):
377		562
378	module \| encode \| decode \|	563	module \| encode \| decode \|
379	-----------\|------------\|------------\|	564	-----------\|------------\|------------\|
380	JSON \| 673 \| 38 \|	565	JSON \| 273.023 \| 44.674 \|
381	JSON::DWIW \| 5271 \| 770 \|	566	JSON::DWIW \| 1089.383 \| 1145.704 \|
382	JSON::PC \| 9901 \| 2491 \|	567	JSON::PC \| 3097.419 \| 2393.921 \|
383	JSON::Syck \| 2360 \| 786 \|	568	JSON::Syck \| 514.060 \| 843.053 \|
384	JSON::XS \| 37398 \| 3202 \|	569	JSON::XS \| 6479.668 \| 3636.364 \|
385	JSON::XS/2 \| 13765 \| 3153 \|	570	JSON::XS/2 \| 3774.221 \| 3599.124 \|
386	-----------+------------+------------+	571	-----------+------------+------------+
387		572
388	Again, JSON::XS leads by far in the encoding case, while still beating	573	Again, JSON::XS leads by far.
389	every other module in the decoding case.
390		574
391	Last example is an almost 8MB large hash with many large binary values	575	On large strings containing lots of high unicode characters, some modules
392	(PNG files), resulting in a lot of escaping:	576	(such as JSON::PC) seem to decode faster than JSON::XS, but the result
		577	will be broken due to missing (or wrong) unicode handling. Others refuse
		578	to decode or encode properly, so it was impossible to prepare a fair
		579	comparison table for that case.
		580
		581	=head1 RESOURCE LIMITS
		582
		583	JSON::XS does not impose any limits on the size of JSON texts or Perl
		584	values they represent - if your machine can handle it, JSON::XS will
		585	encode or decode it. Future versions might optionally impose structure
		586	depth and memory use resource limits.
393		587
394	=head1 BUGS	588	=head1 BUGS
395		589
396	While the goal of this module is to be correct, that unfortunately does	590	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	591	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 1.8 by root, Fri Mar 23 15:57:18 2007 UTC vs. Revision 1.21 by root, Sun Mar 25 02:32:40 2007 UTC

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Comparing JSON-XS/XS.pm (file contents):
Revision 1.8 by root, Fri Mar 23 15:57:18 2007 UTC vs.
Revision 1.21 by root, Sun Mar 25 02:32:40 2007 UTC