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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.3 by root, Thu Mar 22 18:10:29 2007 UTC vs.
Revision 1.17 by root, Sat Mar 24 19:42:14 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	# oo-interface
		15
		16	$coder = JSON::XS->new->ascii->pretty->allow_nonref;
		17	$pretty_printed_unencoded = $coder->encode ($perl_scalar);
		18	$perl_scalar = $coder->decode ($unicode_json_text);
8		19
9	=head1 DESCRIPTION	20	=head1 DESCRIPTION
10		21
11	This module converts Perl data structures to JSON and vice versa. Its	22	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	23	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	29	their maintainers are unresponsive, gone missing, or not listening to bug
19	reports for other reasons.	30	reports for other reasons.
20		31
21	See COMPARISON, below, for a comparison to some other JSON modules.	32	See COMPARISON, below, for a comparison to some other JSON modules.
22		33
		34	See MAPPING, below, on how JSON::XS maps perl values to JSON values and
		35	vice versa.
		36
23	=head2 FEATURES	37	=head2 FEATURES
24		38
25	=over 4	39	=over 4
26		40
27	=item * correct handling of unicode issues	41	=item * correct handling of unicode issues
28		42
29	This module knows how to handle Unicode, and even documents how it does so.	43	This module knows how to handle Unicode, and even documents how and when
		44	it does so.
30		45
31	=item * round-trip integrity	46	=item * round-trip integrity
32		47
33	When you serialise a perl data structure using only datatypes supported	48	When you serialise a perl data structure using only datatypes supported
34	by JSON, the deserialised data structure is identical on the Perl level.	49	by JSON, the deserialised data structure is identical on the Perl level.
35	(e.g. the string "2.0" doesn't suddenly become "2").	50	(e.g. the string "2.0" doesn't suddenly become "2").
36		51
37	=item * strict checking of JSON correctness	52	=item * strict checking of JSON correctness
38		53
39	There is no guessing, no generating of illegal JSON strings by default,	54	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).	55	and only JSON is accepted as input by default (the latter is a security
		56	feature).
41		57
42	=item * fast	58	=item * fast
43		59
44	compared to other JSON modules, this module compares favourably.	60	Compared to other JSON modules, this module compares favourably in terms
		61	of speed, too.
45		62
46	=item * simple to use	63	=item * simple to use
47		64
48	This module has both a simple functional interface as well as an OO	65	This module has both a simple functional interface as well as an OO
49	interface.	66	interface.
50		67
51	=item * reasonably versatile output formats	68	=item * reasonably versatile output formats
52		69
53	You can choose between the most compact format possible, a pure-ascii	70	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	71	possible (nice for simple line-based protocols), a pure-ascii format (for
		72	when your transport is not 8-bit clean), or a pretty-printed format (for
		73	when you want to read that stuff). Or you can combine those features in
55	whatever way you like.	74	whatever way you like.
56		75
57	=back	76	=back
58		77
59	=cut	78	=cut
60		79
61	package JSON::XS;	80	package JSON::XS;
62		81
63	BEGIN {	82	BEGIN {
64	$VERSION = '0.1';	83	$VERSION = '0.5';
65	@ISA = qw(Exporter);	84	@ISA = qw(Exporter);
66		85
67	@EXPORT = qw(to_json from_json);	86	@EXPORT = qw(to_json from_json);
68	require Exporter;	87	require Exporter;
69		88
…		…
76	The following convinience methods are provided by this module. They are	95	The following convinience methods are provided by this module. They are
77	exported by default:	96	exported by default:
78		97
79	=over 4	98	=over 4
80		99
81	=item $json_string = to_json $perl_scalar	100	=item $json_text = to_json $perl_scalar
82		101
83	Converts the given Perl data structure (a simple scalar or a reference to	102	Converts the given Perl data structure (a simple scalar or a reference to
84	a hash or array) to a UTF-8 encoded, binary string (that is, the string contains	103	a hash or array) to a UTF-8 encoded, binary string (that is, the string contains
85	octets only). Croaks on error.	104	octets only). Croaks on error.
86		105
87	This function call is functionally identical to C<< JSON::XS->new->utf8	106	This function call is functionally identical to:
88	(1)->encode ($perl_scalar) >>.
89		107
		108	$json_text = JSON::XS->new->utf8->encode ($perl_scalar)
		109
		110	except being faster.
		111
90	=item $perl_scalar = from_json $json_string	112	=item $perl_scalar = from_json $json_text
91		113
92	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to	114	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to
93	parse that as an UTF-8 encoded JSON string, returning the resulting simple	115	parse that as an UTF-8 encoded JSON text, returning the resulting simple
94	scalar or reference. Croaks on error.	116	scalar or reference. Croaks on error.
95		117
96	This function call is functionally identical to C<< JSON::XS->new->utf8	118	This function call is functionally identical to:
97	(1)->decode ($json_string) >>.	119
		120	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)
		121
		122	except being faster.
98		123
99	=back	124	=back
100		125
101	=head1 OBJECT-ORIENTED INTERFACE	126	=head1 OBJECT-ORIENTED INTERFACE
102		127
…		…
111	strings. All boolean flags described below are by default I<disabled>.	136	strings. All boolean flags described below are by default I<disabled>.
112		137
113	The mutators for flags all return the JSON object again and thus calls can	138	The mutators for flags all return the JSON object again and thus calls can
114	be chained:	139	be chained:
115		140
116	my $json = JSON::XS->new->utf8(1)->space_after(1)->encode ({a => [1,2]})	141	my $json = JSON::XS->new->utf8->space_after->encode ({a => [1,2]})
117	=> {"a": [1, 2]}	142	=> {"a": [1, 2]}
118		143
119	=item $json = $json->ascii ($enable)	144	=item $json = $json->ascii ([$enable])
120		145
121	If C<$enable> is true, then the C<encode> method will not generate	146	If C<$enable> is true (or missing), then the C<encode> method will not
122	characters outside the code range C<0..127>. Any unicode characters	147	generate characters outside the code range C<0..127> (which is ASCII). Any
123	outside that range will be escaped using either a single \uXXXX (BMP	148	unicode characters outside that range will be escaped using either a
124	characters) or a double \uHHHH\uLLLLL escape sequence, as per RFC4627.	149	single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence,
		150	as per RFC4627.
125		151
126	If C<$enable> is false, then the C<encode> method will not escape Unicode	152	If C<$enable> is false, then the C<encode> method will not escape Unicode
127	characters unless necessary.	153	characters unless required by the JSON syntax. This results in a faster
		154	and more compact format.
128		155
129	JSON::XS->new->ascii (1)->encode (chr 0x10401)	156	JSON::XS->new->ascii (1)->encode ([chr 0x10401])
130	=> \ud801\udc01	157	=> ["\ud801\udc01"]
131		158
132	=item $json = $json->utf8 ($enable)	159	=item $json = $json->utf8 ([$enable])
133		160
134	If C<$enable> is true, then the C<encode> method will encode the JSON	161	If C<$enable> is true (or missing), then the C<encode> method will encode
135	string into UTF-8, as required by many protocols, while the C<decode>	162	the JSON result into UTF-8, as required by many protocols, while the
136	method expects to be handled an UTF-8-encoded string. Please note that	163	C<decode> method expects to be handled an UTF-8-encoded string. Please
137	UTF-8-encoded strings do not contain any characters outside the range	164	note that UTF-8-encoded strings do not contain any characters outside the
138	C<0..255>, they are thus useful for bytewise/binary I/O.	165	range C<0..255>, they are thus useful for bytewise/binary I/O. In future
		166	versions, enabling this option might enable autodetection of the UTF-16
		167	and UTF-32 encoding families, as described in RFC4627.
139		168
140	If C<$enable> is false, then the C<encode> method will return the JSON	169	If C<$enable> is false, then the C<encode> method will return the JSON
141	string as a (non-encoded) unicode string, while C<decode> expects thus a	170	string as a (non-encoded) unicode string, while C<decode> expects thus a
142	unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs	171	unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs
143	to be done yourself, e.g. using the Encode module.	172	to be done yourself, e.g. using the Encode module.
144		173
		174	Example, output UTF-16BE-encoded JSON:
		175
		176	use Encode;
		177	$jsontext = encode "UTF-16BE", JSON::XS->new->encode ($object);
		178
		179	Example, decode UTF-32LE-encoded JSON:
		180
		181	use Encode;
		182	$object = JSON::XS->new->decode (decode "UTF-32LE", $jsontext);
		183
145	=item $json = $json->pretty ($enable)	184	=item $json = $json->pretty ([$enable])
146		185
147	This enables (or disables) all of the C<indent>, C<space_before> and	186	This enables (or disables) all of the C<indent>, C<space_before> and
148	C<space_after> (and in the future possibly more) flags in one call to	187	C<space_after> (and in the future possibly more) flags in one call to
149	generate the most readable (or most compact) form possible.	188	generate the most readable (or most compact) form possible.
		189
		190	Example, pretty-print some simple structure:
150		191
151	my $json = JSON::XS->new->pretty(1)->encode ({a => [1,2]})	192	my $json = JSON::XS->new->pretty(1)->encode ({a => [1,2]})
152	=>	193	=>
153	{	194	{
154	"a" : [	195	"a" : [
155	1,	196	1,
156	2	197	2
157	]	198	]
158	}	199	}
159		200
160	=item $json = $json->indent ($enable)	201	=item $json = $json->indent ([$enable])
161		202
162	If C<$enable> is true, then the C<encode> method will use a multiline	203	If C<$enable> is true (or missing), then the C<encode> method will use a multiline
163	format as output, putting every array member or object/hash key-value pair	204	format as output, putting every array member or object/hash key-value pair
164	into its own line, identing them properly.	205	into its own line, identing them properly.
165		206
166	If C<$enable> is false, no newlines or indenting will be produced, and the	207	If C<$enable> is false, no newlines or indenting will be produced, and the
167	resulting JSON strings is guarenteed not to contain any C<newlines>.	208	resulting JSON text is guarenteed not to contain any C<newlines>.
168		209
169	This setting has no effect when decoding JSON strings.	210	This setting has no effect when decoding JSON texts.
170		211
171	=item $json = $json->space_before ($enable)	212	=item $json = $json->space_before ([$enable])
172		213
173	If C<$enable> is true, then the C<encode> method will add an extra	214	If C<$enable> is true (or missing), then the C<encode> method will add an extra
174	optional space before the C<:> separating keys from values in JSON objects.	215	optional space before the C<:> separating keys from values in JSON objects.
175		216
176	If C<$enable> is false, then the C<encode> method will not add any extra	217	If C<$enable> is false, then the C<encode> method will not add any extra
177	space at those places.	218	space at those places.
178		219
179	This setting has no effect when decoding JSON strings. You will also most	220	This setting has no effect when decoding JSON texts. You will also
180	likely combine this setting with C<space_after>.	221	most likely combine this setting with C<space_after>.
181		222
		223	Example, space_before enabled, space_after and indent disabled:
		224
		225	{"key" :"value"}
		226
182	=item $json = $json->space_after ($enable)	227	=item $json = $json->space_after ([$enable])
183		228
184	If C<$enable> is true, then the C<encode> method will add an extra	229	If C<$enable> is true (or missing), then the C<encode> method will add an extra
185	optional space after the C<:> separating keys from values in JSON objects	230	optional space after the C<:> separating keys from values in JSON objects
186	and extra whitespace after the C<,> separating key-value pairs and array	231	and extra whitespace after the C<,> separating key-value pairs and array
187	members.	232	members.
188		233
189	If C<$enable> is false, then the C<encode> method will not add any extra	234	If C<$enable> is false, then the C<encode> method will not add any extra
190	space at those places.	235	space at those places.
191		236
192	This setting has no effect when decoding JSON strings.	237	This setting has no effect when decoding JSON texts.
193		238
		239	Example, space_before and indent disabled, space_after enabled:
		240
		241	{"key": "value"}
		242
194	=item $json = $json->canonical ($enable)	243	=item $json = $json->canonical ([$enable])
195		244
196	If C<$enable> is true, then the C<encode> method will output JSON objects	245	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects
197	by sorting their keys. This is adding a comparatively high overhead.	246	by sorting their keys. This is adding a comparatively high overhead.
198		247
199	If C<$enable> is false, then the C<encode> method will output key-value	248	If C<$enable> is false, then the C<encode> method will output key-value
200	pairs in the order Perl stores them (which will likely change between runs	249	pairs in the order Perl stores them (which will likely change between runs
201	of the same script).	250	of the same script).
202		251
203	This option is useful if you want the same data structure to be encoded as	252	This option is useful if you want the same data structure to be encoded as
204	the same JSON string (given the same overall settings). If it is disabled,	253	the same JSON text (given the same overall settings). If it is disabled,
205	the same hash migh be encoded differently even if contains the same data,	254	the same hash migh be encoded differently even if contains the same data,
206	as key-value pairs have no inherent ordering in Perl.	255	as key-value pairs have no inherent ordering in Perl.
207		256
208	This setting has no effect when decoding JSON strings.	257	This setting has no effect when decoding JSON texts.
209		258
210	=item $json = $json->allow_nonref ($enable)	259	=item $json = $json->allow_nonref ([$enable])
211		260
212	If C<$enable> is true, then the C<encode> method can convert a	261	If C<$enable> is true (or missing), then the C<encode> method can convert a
213	non-reference into its corresponding string, number or null JSON value,	262	non-reference into its corresponding string, number or null JSON value,
214	which is an extension to RFC4627. Likewise, C<decode> will accept those JSON	263	which is an extension to RFC4627. Likewise, C<decode> will accept those JSON
215	values instead of croaking.	264	values instead of croaking.
216		265
217	If C<$enable> is false, then the C<encode> method will croak if it isn't	266	If C<$enable> is false, then the C<encode> method will croak if it isn't
218	passed an arrayref or hashref, as JSON strings must either be an object	267	passed an arrayref or hashref, as JSON texts must either be an object
219	or array. Likewise, C<decode> will croak if given something that is not a	268	or array. Likewise, C<decode> will croak if given something that is not a
220	JSON object or array.	269	JSON object or array.
221		270
		271	Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,
		272	resulting in an invalid JSON text:
		273
		274	JSON::XS->new->allow_nonref->encode ("Hello, World!")
		275	=> "Hello, World!"
		276
		277	=item $json = $json->shrink ([$enable])
		278
		279	Perl usually over-allocates memory a bit when allocating space for
		280	strings. This flag optionally resizes strings generated by either
		281	C<encode> or C<decode> to their minimum size possible. This can save
		282	memory when your JSON texts are either very very long or you have many
		283	short strings. It will also try to downgrade any strings to octet-form
		284	if possible: perl stores strings internally either in an encoding called
		285	UTF-X or in octet-form. The latter cannot store everything but uses less
		286	space in general.
		287
		288	If C<$enable> is true (or missing), the string returned by C<encode> will be shrunk-to-fit,
		289	while all strings generated by C<decode> will also be shrunk-to-fit.
		290
		291	If C<$enable> is false, then the normal perl allocation algorithms are used.
		292	If you work with your data, then this is likely to be faster.
		293
		294	In the future, this setting might control other things, such as converting
		295	strings that look like integers or floats into integers or floats
		296	internally (there is no difference on the Perl level), saving space.
		297
222	=item $json_string = $json->encode ($perl_scalar)	298	=item $json_text = $json->encode ($perl_scalar)
223		299
224	Converts the given Perl data structure (a simple scalar or a reference	300	Converts the given Perl data structure (a simple scalar or a reference
225	to a hash or array) to its JSON representation. Simple scalars will be	301	to a hash or array) to its JSON representation. Simple scalars will be
226	converted into JSON string or number sequences, while references to arrays	302	converted into JSON string or number sequences, while references to arrays
227	become JSON arrays and references to hashes become JSON objects. Undefined	303	become JSON arrays and references to hashes become JSON objects. Undefined
228	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>	304	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>
229	nor C<false> values will be generated.	305	nor C<false> values will be generated.
230		306
231	=item $perl_scalar = $json->decode ($json_string)	307	=item $perl_scalar = $json->decode ($json_text)
232		308
233	The opposite of C<encode>: expects a JSON string and tries to parse it,	309	The opposite of C<encode>: expects a JSON text and tries to parse it,
234	returning the resulting simple scalar or reference. Croaks on error.	310	returning the resulting simple scalar or reference. Croaks on error.
235		311
236	JSON numbers and strings become simple Perl scalars. JSON arrays become	312	JSON numbers and strings become simple Perl scalars. JSON arrays become
237	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes	313	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes
238	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.	314	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.
239		315
240	=back	316	=back
241		317
		318	=head1 MAPPING
		319
		320	This section describes how JSON::XS maps Perl values to JSON values and
		321	vice versa. These mappings are designed to "do the right thing" in most
		322	circumstances automatically, preserving round-tripping characteristics
		323	(what you put in comes out as something equivalent).
		324
		325	For the more enlightened: note that in the following descriptions,
		326	lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl>
		327	refers to the abstract Perl language itself.
		328
		329	=head2 JSON -> PERL
		330
		331	=over 4
		332
		333	=item object
		334
		335	A JSON object becomes a reference to a hash in Perl. No ordering of object
		336	keys is preserved (JSON does not preserver object key ordering itself).
		337
		338	=item array
		339
		340	A JSON array becomes a reference to an array in Perl.
		341
		342	=item string
		343
		344	A JSON string becomes a string scalar in Perl - Unicode codepoints in JSON
		345	are represented by the same codepoints in the Perl string, so no manual
		346	decoding is necessary.
		347
		348	=item number
		349
		350	A JSON number becomes either an integer or numeric (floating point)
		351	scalar in perl, depending on its range and any fractional parts. On the
		352	Perl level, there is no difference between those as Perl handles all the
		353	conversion details, but an integer may take slightly less memory and might
		354	represent more values exactly than (floating point) numbers.
		355
		356	=item true, false
		357
		358	These JSON atoms become C<0>, C<1>, respectively. Information is lost in
		359	this process. Future versions might represent those values differently,
		360	but they will be guarenteed to act like these integers would normally in
		361	Perl.
		362
		363	=item null
		364
		365	A JSON null atom becomes C<undef> in Perl.
		366
		367	=back
		368
		369	=head2 PERL -> JSON
		370
		371	The mapping from Perl to JSON is slightly more difficult, as Perl is a
		372	truly typeless language, so we can only guess which JSON type is meant by
		373	a Perl value.
		374
		375	=over 4
		376
		377	=item hash references
		378
		379	Perl hash references become JSON objects. As there is no inherent ordering
		380	in hash keys, they will usually be encoded in a pseudo-random order that
		381	can change between runs of the same program but stays generally the same
		382	within a single run of a program. JSON::XS can optionally sort the hash
		383	keys (determined by the I<canonical> flag), so the same datastructure
		384	will serialise to the same JSON text (given same settings and version of
		385	JSON::XS), but this incurs a runtime overhead.
		386
		387	=item array references
		388
		389	Perl array references become JSON arrays.
		390
		391	=item blessed objects
		392
		393	Blessed objects are not allowed. JSON::XS currently tries to encode their
		394	underlying representation (hash- or arrayref), but this behaviour might
		395	change in future versions.
		396
		397	=item simple scalars
		398
		399	Simple Perl scalars (any scalar that is not a reference) are the most
		400	difficult objects to encode: JSON::XS will encode undefined scalars as
		401	JSON null value, scalars that have last been used in a string context
		402	before encoding as JSON strings and anything else as number value:
		403
		404	# dump as number
		405	to_json [2] # yields [2]
		406	to_json [-3.0e17] # yields [-3e+17]
		407	my $value = 5; to_json [$value] # yields [5]
		408
		409	# used as string, so dump as string
		410	print $value;
		411	to_json [$value] # yields ["5"]
		412
		413	# undef becomes null
		414	to_json [undef] # yields [null]
		415
		416	You can force the type to be a string by stringifying it:
		417
		418	my $x = 3.1; # some variable containing a number
		419	"$x"; # stringified
		420	$x .= ""; # another, more awkward way to stringify
		421	print $x; # perl does it for you, too, quite often
		422
		423	You can force the type to be a number by numifying it:
		424
		425	my $x = "3"; # some variable containing a string
		426	$x += 0; # numify it, ensuring it will be dumped as a number
		427	$x *= 1; # same thing, the choise is yours.
		428
		429	You can not currently output JSON booleans or force the type in other,
		430	less obscure, ways. Tell me if you need this capability.
		431
		432	=item circular data structures
		433
		434	Those will be encoded until memory or stackspace runs out.
		435
		436	=back
		437
242	=head1 COMPARISON	438	=head1 COMPARISON
243		439
244	As already mentioned, this module was created because none of the existing	440	As already mentioned, this module was created because none of the existing
245	JSON modules could be made to work correctly. First I will describe the	441	JSON modules could be made to work correctly. First I will describe the
246	problems (or pleasures) I encountered with various existing JSON modules,	442	problems (or pleasures) I encountered with various existing JSON modules,
247	followed by some benchmark values.	443	followed by some benchmark values. JSON::XS was designed not to suffer
		444	from any of these problems or limitations.
248		445
249	=over 4	446	=over 4
250		447
251	=item JSON	448	=item JSON 1.07
252		449
253	Slow (but very portable, as it is written in pure Perl).	450	Slow (but very portable, as it is written in pure Perl).
254		451
255	Undocumented/buggy Unicode handling (how JSON handles unicode values is	452	Undocumented/buggy Unicode handling (how JSON handles unicode values is
256	undocumented. One can get far by feeding it unicode strings and doing	453	undocumented. One can get far by feeding it unicode strings and doing
…		…
258		455
259	No roundtripping (strings get clobbered if they look like numbers, e.g.	456	No roundtripping (strings get clobbered if they look like numbers, e.g.
260	the string C<2.0> will encode to C<2.0> instead of C<"2.0">, and that will	457	the string C<2.0> will encode to C<2.0> instead of C<"2.0">, and that will
261	decode into the number 2.	458	decode into the number 2.
262		459
263	=item JSON::PC	460	=item JSON::PC 0.01
264		461
265	Very fast.	462	Very fast.
		463
		464	Undocumented/buggy Unicode handling.
		465
		466	No roundtripping.
		467
		468	Has problems handling many Perl values (e.g. regex results and other magic
		469	values will make it croak).
		470
		471	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>
		472	which is not a valid JSON text.
		473
		474	Unmaintained (maintainer unresponsive for many months, bugs are not
		475	getting fixed).
		476
		477	=item JSON::Syck 0.21
		478
		479	Very buggy (often crashes).
266		480
267	Very inflexible (no human-readable format supported, format pretty much	481	Very inflexible (no human-readable format supported, format pretty much
268	undocumented. I need at least a format for easy reading by humans and a	482	undocumented. I need at least a format for easy reading by humans and a
269	single-line compact format for use in a protocol, and preferably a way to	483	single-line compact format for use in a protocol, and preferably a way to
270	generate ASCII-only JSON strings).	484	generate ASCII-only JSON texts).
271
272	Undocumented/buggy Unicode handling.
273
274	No roundtripping.
275
276	Has problems handling many Perl values.
277
278	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>
279	which is not a valid JSON string.
280
281	Unmaintained (maintainer unresponsive for many months, bugs are not
282	getting fixed).
283
284	=item JSON::Syck
285
286	Very buggy (often crashes).
287
288	Very inflexible.
289		485
290	Completely broken (and confusingly documented) Unicode handling (unicode	486	Completely broken (and confusingly documented) Unicode handling (unicode
291	escapes are not working properly, you need to set ImplicitUnicode to	487	escapes are not working properly, you need to set ImplicitUnicode to
292	I<different> values on en- and decoding to get symmetric behaviour).	488	I<different> values on en- and decoding to get symmetric behaviour).
293		489
…		…
305	JSON. One bank might parse a given non-JSON request and deduct money,	501	JSON. One bank might parse a given non-JSON request and deduct money,
306	while the other might reject the transaction with a syntax error. While a	502	while the other might reject the transaction with a syntax error. While a
307	good protocol will at least recover, that is extra unnecessary work and	503	good protocol will at least recover, that is extra unnecessary work and
308	the transaction will still not succeed).	504	the transaction will still not succeed).
309		505
310	=item JSON::DWIW	506	=item JSON::DWIW 0.04
311		507
312	Very fast. Very natural. Very nice.	508	Very fast. Very natural. Very nice.
313		509
314	Undocumented unicode handling (but the best of the pack. Unicode escapes	510	Undocumented unicode handling (but the best of the pack. Unicode escapes
315	still don't get parsed properly).	511	still don't get parsed properly).
316		512
317	Very inflexible.	513	Very inflexible.
318		514
319	No roundtripping.	515	No roundtripping.
320		516
		517	Does not generate valid JSON texts (key strings are often unquoted, empty keys
		518	result in nothing being output)
		519
321	Does not check input for validity.	520	Does not check input for validity.
322		521
323	=back	522	=back
324		523
325	=head2 SPEED	524	=head2 SPEED
		525
		526	It seems that JSON::XS is surprisingly fast, as shown in the following
		527	tables. They have been generated with the help of the C<eg/bench> program
		528	in the JSON::XS distribution, to make it easy to compare on your own
		529	system.
		530
		531	First comes a comparison between various modules using a very short JSON
		532	string (83 bytes), showing the number of encodes/decodes per second
		533	(JSON::XS is the functional interface, while JSON::XS/2 is the OO
		534	interface with pretty-printing and hashkey sorting enabled). Higher is
		535	better:
		536
		537	module \| encode \| decode \|
		538	-----------\|------------\|------------\|
		539	JSON \| 14006 \| 6820 \|
		540	JSON::DWIW \| 200937 \| 120386 \|
		541	JSON::PC \| 85065 \| 129366 \|
		542	JSON::Syck \| 59898 \| 44232 \|
		543	JSON::XS \| 1171478 \| 342435 \|
		544	JSON::XS/2 \| 730760 \| 328714 \|
		545	-----------+------------+------------+
		546
		547	That is, JSON::XS is 6 times faster than than JSON::DWIW and about 80
		548	times faster than JSON, even with pretty-printing and key sorting.
		549
		550	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
		551	search API (http://nanoref.com/yahooapis/mgPdGg):
		552
		553	module \| encode \| decode \|
		554	-----------\|------------\|------------\|
		555	JSON \| 673 \| 38 \|
		556	JSON::DWIW \| 5271 \| 770 \|
		557	JSON::PC \| 9901 \| 2491 \|
		558	JSON::Syck \| 2360 \| 786 \|
		559	JSON::XS \| 37398 \| 3202 \|
		560	JSON::XS/2 \| 13765 \| 3153 \|
		561	-----------+------------+------------+
		562
		563	Again, JSON::XS leads by far in the encoding case, while still beating
		564	every other module in the decoding case.
		565
		566	On large strings containing lots of unicode characters, some modules
		567	(such as JSON::PC) decode faster than JSON::XS, but the result will be
		568	broken due to missing unicode handling. Others refuse to decode or encode
		569	properly, so it was impossible to prepare a fair comparison table for that
		570	case.
		571
		572	=head1 RESOURCE LIMITS
		573
		574	JSON::XS does not impose any limits on the size of JSON texts or Perl
		575	values they represent - if your machine can handle it, JSON::XS will
		576	encode or decode it. Future versions might optionally impose structure
		577	depth and memory use resource limits.
		578
		579	=head1 BUGS
		580
		581	While the goal of this module is to be correct, that unfortunately does
		582	not mean its bug-free, only that I think its design is bug-free. It is
		583	still very young and not well-tested. If you keep reporting bugs they will
		584	be fixed swiftly, though.
326		585
327	=cut	586	=cut
328		587
329	1;	588	1;
330		589

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Comparing JSON-XS/XS.pm (file contents): Revision 1.3 by root, Thu Mar 22 18:10:29 2007 UTC vs. Revision 1.17 by root, Sat Mar 24 19:42:14 2007 UTC

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Comparing JSON-XS/XS.pm (file contents):
Revision 1.3 by root, Thu Mar 22 18:10:29 2007 UTC vs.
Revision 1.17 by root, Sat Mar 24 19:42:14 2007 UTC