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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.74 by root, Wed Nov 28 13:57:15 2007 UTC vs.
Revision 1.103 by root, Tue Apr 29 16:07:56 2008 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	JSON::XS - JSON serialising/deserialising, done correctly and fast	3	JSON::XS - JSON serialising/deserialising, done correctly and fast
		4
		5	=encoding utf-8
4		6
5	JSON::XS - 正しくて高速な JSON シリアライザ/デシリアライザ	7	JSON::XS - 正しくて高速な JSON シリアライザ/デシリアライザ
6	(http://fleur.hio.jp/perldoc/mix/lib/JSON/XS.html)	8	(http://fleur.hio.jp/perldoc/mix/lib/JSON/XS.html)
7		9
8	=head1 SYNOPSIS	10	=head1 SYNOPSIS
10	use JSON::XS;	12	use JSON::XS;
11		13
12	# exported functions, they croak on error	14	# exported functions, they croak on error
13	# and expect/generate UTF-8	15	# and expect/generate UTF-8
14		16
15	$utf8_encoded_json_text = to_json $perl_hash_or_arrayref;	17	$utf8_encoded_json_text = encode_json $perl_hash_or_arrayref;
16	$perl_hash_or_arrayref = from_json $utf8_encoded_json_text;	18	$perl_hash_or_arrayref = decode_json $utf8_encoded_json_text;
17		19
18	# OO-interface	20	# OO-interface
19		21
20	$coder = JSON::XS->new->ascii->pretty->allow_nonref;	22	$coder = JSON::XS->new->ascii->pretty->allow_nonref;
21	$pretty_printed_unencoded = $coder->encode ($perl_scalar);	23	$pretty_printed_unencoded = $coder->encode ($perl_scalar);
22	$perl_scalar = $coder->decode ($unicode_json_text);	24	$perl_scalar = $coder->decode ($unicode_json_text);
23		25
		26	# Note that JSON version 2.0 and above will automatically use JSON::XS
		27	# if available, at virtually no speed overhead either, so you should
		28	# be able to just:
		29
		30	use JSON;
		31
		32	# and do the same things, except that you have a pure-perl fallback now.
		33
24	=head1 DESCRIPTION	34	=head1 DESCRIPTION
25		35
26	This module converts Perl data structures to JSON and vice versa. Its	36	This module converts Perl data structures to JSON and vice versa. Its
27	primary goal is to be I<correct> and its secondary goal is to be	37	primary goal is to be I<correct> and its secondary goal is to be
28	I<fast>. To reach the latter goal it was written in C.	38	I<fast>. To reach the latter goal it was written in C.
		39
		40	Beginning with version 2.0 of the JSON module, when both JSON and
		41	JSON::XS are installed, then JSON will fall back on JSON::XS (this can be
		42	overriden) with no overhead due to emulation (by inheritign constructor
		43	and methods). If JSON::XS is not available, it will fall back to the
		44	compatible JSON::PP module as backend, so using JSON instead of JSON::XS
		45	gives you a portable JSON API that can be fast when you need and doesn't
		46	require a C compiler when that is a problem.
29		47
30	As this is the n-th-something JSON module on CPAN, what was the reason	48	As this is the n-th-something JSON module on CPAN, what was the reason
31	to write yet another JSON module? While it seems there are many JSON	49	to write yet another JSON module? While it seems there are many JSON
32	modules, none of them correctly handle all corner cases, and in most cases	50	modules, none of them correctly handle all corner cases, and in most cases
33	their maintainers are unresponsive, gone missing, or not listening to bug	51	their maintainers are unresponsive, gone missing, or not listening to bug
…		…
42		60
43	=over 4	61	=over 4
44		62
45	=item * correct Unicode handling	63	=item * correct Unicode handling
46		64
47	This module knows how to handle Unicode, and even documents how and when	65	This module knows how to handle Unicode, documents how and when it does
48	it does so.	66	so, and even documents what "correct" means.
49		67
50	=item * round-trip integrity	68	=item * round-trip integrity
51		69
52	When you serialise a perl data structure using only datatypes supported	70	When you serialise a perl data structure using only datatypes supported
53	by JSON, the deserialised data structure is identical on the Perl level.	71	by JSON, the deserialised data structure is identical on the Perl level.
54	(e.g. the string "2.0" doesn't suddenly become "2" just because it looks	72	(e.g. the string "2.0" doesn't suddenly become "2" just because it looks
55	like a number).	73	like a number). There minor I<are> exceptions to this, read the MAPPING
		74	section below to learn about those.
56		75
57	=item * strict checking of JSON correctness	76	=item * strict checking of JSON correctness
58		77
59	There is no guessing, no generating of illegal JSON texts by default,	78	There is no guessing, no generating of illegal JSON texts by default,
60	and only JSON is accepted as input by default (the latter is a security	79	and only JSON is accepted as input by default (the latter is a security
61	feature).	80	feature).
62		81
63	=item * fast	82	=item * fast
64		83
65	Compared to other JSON modules, this module compares favourably in terms	84	Compared to other JSON modules and other serialisers such as Storable,
66	of speed, too.	85	this module usually compares favourably in terms of speed, too.
67		86
68	=item * simple to use	87	=item * simple to use
69		88
70	This module has both a simple functional interface as well as an OO	89	This module has both a simple functional interface as well as an objetc
71	interface.	90	oriented interface interface.
72		91
73	=item * reasonably versatile output formats	92	=item * reasonably versatile output formats
74		93
75	You can choose between the most compact guaranteed single-line format	94	You can choose between the most compact guaranteed-single-line format
76	possible (nice for simple line-based protocols), a pure-ascii format	95	possible (nice for simple line-based protocols), a pure-ascii format
77	(for when your transport is not 8-bit clean, still supports the whole	96	(for when your transport is not 8-bit clean, still supports the whole
78	Unicode range), or a pretty-printed format (for when you want to read that	97	Unicode range), or a pretty-printed format (for when you want to read that
79	stuff). Or you can combine those features in whatever way you like.	98	stuff). Or you can combine those features in whatever way you like.
80		99
…		…
84		103
85	package JSON::XS;	104	package JSON::XS;
86		105
87	use strict;	106	use strict;
88		107
89	our $VERSION = '2.0';	108	our $VERSION = '2.2';
90	our @ISA = qw(Exporter);	109	our @ISA = qw(Exporter);
91		110
92	our @EXPORT = qw(to_json from_json);	111	our @EXPORT = qw(encode_json decode_json to_json from_json);
		112
		113	sub to_json($) {
		114	require Carp;
		115	Carp::croak ("JSON::XS::to_json has been renamed to encode_json, either downgrade to pre-2.0 versions of JSON::XS or rename the call");
		116	}
		117
		118	sub from_json($) {
		119	require Carp;
		120	Carp::croak ("JSON::XS::from_json has been renamed to decode_json, either downgrade to pre-2.0 versions of JSON::XS or rename the call");
		121	}
93		122
94	use Exporter;	123	use Exporter;
95	use XSLoader;	124	use XSLoader;
96		125
97	=head1 FUNCTIONAL INTERFACE	126	=head1 FUNCTIONAL INTERFACE
…		…
99	The following convenience methods are provided by this module. They are	128	The following convenience methods are provided by this module. They are
100	exported by default:	129	exported by default:
101		130
102	=over 4	131	=over 4
103		132
104	=item $json_text = to_json $perl_scalar	133	=item $json_text = encode_json $perl_scalar
105		134
106	Converts the given Perl data structure to a UTF-8 encoded, binary string	135	Converts the given Perl data structure to a UTF-8 encoded, binary string
107	(that is, the string contains octets only). Croaks on error.	136	(that is, the string contains octets only). Croaks on error.
108		137
109	This function call is functionally identical to:	138	This function call is functionally identical to:
110		139
111	$json_text = JSON::XS->new->utf8->encode ($perl_scalar)	140	$json_text = JSON::XS->new->utf8->encode ($perl_scalar)
112		141
113	except being faster.	142	except being faster.
114		143
115	=item $perl_scalar = from_json $json_text	144	=item $perl_scalar = decode_json $json_text
116		145
117	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries	146	The opposite of C<encode_json>: expects an UTF-8 (binary) string and tries
118	to parse that as an UTF-8 encoded JSON text, returning the resulting	147	to parse that as an UTF-8 encoded JSON text, returning the resulting
119	reference. Croaks on error.	148	reference. Croaks on error.
120		149
121	This function call is functionally identical to:	150	This function call is functionally identical to:
122		151
…		…
148	This enables you to store Unicode characters as single characters in a	177	This enables you to store Unicode characters as single characters in a
149	Perl string - very natural.	178	Perl string - very natural.
150		179
151	=item 2. Perl does I<not> associate an encoding with your strings.	180	=item 2. Perl does I<not> associate an encoding with your strings.
152		181
153	Unless you force it to, e.g. when matching it against a regex, or printing	182	... until you force it to, e.g. when matching it against a regex, or
154	the scalar to a file, in which case Perl either interprets your string as	183	printing the scalar to a file, in which case Perl either interprets your
155	locale-encoded text, octets/binary, or as Unicode, depending on various	184	string as locale-encoded text, octets/binary, or as Unicode, depending
156	settings. In no case is an encoding stored together with your data, it is	185	on various settings. In no case is an encoding stored together with your
157	I<use> that decides encoding, not any magical metadata.	186	data, it is I<use> that decides encoding, not any magical meta data.
158		187
159	=item 3. The internal utf-8 flag has no meaning with regards to the	188	=item 3. The internal utf-8 flag has no meaning with regards to the
160	encoding of your string.	189	encoding of your string.
161		190
162	Just ignore that flag unless you debug a Perl bug, a module written in	191	Just ignore that flag unless you debug a Perl bug, a module written in
…		…
216		245
217	If C<$enable> is false, then the C<encode> method will not escape Unicode	246	If C<$enable> is false, then the C<encode> method will not escape Unicode
218	characters unless required by the JSON syntax or other flags. This results	247	characters unless required by the JSON syntax or other flags. This results
219	in a faster and more compact format.	248	in a faster and more compact format.
220		249
		250	See also the section I<ENCODING/CODESET FLAG NOTES> later in this
		251	document.
		252
221	The main use for this flag is to produce JSON texts that can be	253	The main use for this flag is to produce JSON texts that can be
222	transmitted over a 7-bit channel, as the encoded JSON texts will not	254	transmitted over a 7-bit channel, as the encoded JSON texts will not
223	contain any 8 bit characters.	255	contain any 8 bit characters.
224		256
225	JSON::XS->new->ascii (1)->encode ([chr 0x10401])	257	JSON::XS->new->ascii (1)->encode ([chr 0x10401])
…		…
236	will not be affected in any way by this flag, as C<decode> by default	268	will not be affected in any way by this flag, as C<decode> by default
237	expects Unicode, which is a strict superset of latin1.	269	expects Unicode, which is a strict superset of latin1.
238		270
239	If C<$enable> is false, then the C<encode> method will not escape Unicode	271	If C<$enable> is false, then the C<encode> method will not escape Unicode
240	characters unless required by the JSON syntax or other flags.	272	characters unless required by the JSON syntax or other flags.
		273
		274	See also the section I<ENCODING/CODESET FLAG NOTES> later in this
		275	document.
241		276
242	The main use for this flag is efficiently encoding binary data as JSON	277	The main use for this flag is efficiently encoding binary data as JSON
243	text, as most octets will not be escaped, resulting in a smaller encoded	278	text, as most octets will not be escaped, resulting in a smaller encoded
244	size. The disadvantage is that the resulting JSON text is encoded	279	size. The disadvantage is that the resulting JSON text is encoded
245	in latin1 (and must correctly be treated as such when storing and	280	in latin1 (and must correctly be treated as such when storing and
…		…
264		299
265	If C<$enable> is false, then the C<encode> method will return the JSON	300	If C<$enable> is false, then the C<encode> method will return the JSON
266	string as a (non-encoded) Unicode string, while C<decode> expects thus a	301	string as a (non-encoded) Unicode string, while C<decode> expects thus a
267	Unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs	302	Unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs
268	to be done yourself, e.g. using the Encode module.	303	to be done yourself, e.g. using the Encode module.
		304
		305	See also the section I<ENCODING/CODESET FLAG NOTES> later in this
		306	document.
269		307
270	Example, output UTF-16BE-encoded JSON:	308	Example, output UTF-16BE-encoded JSON:
271		309
272	use Encode;	310	use Encode;
273	$jsontext = encode "UTF-16BE", JSON::XS->new->encode ($object);	311	$jsontext = encode "UTF-16BE", JSON::XS->new->encode ($object);
…		…
425	resulting in an invalid JSON text:	463	resulting in an invalid JSON text:
426		464
427	JSON::XS->new->allow_nonref->encode ("Hello, World!")	465	JSON::XS->new->allow_nonref->encode ("Hello, World!")
428	=> "Hello, World!"	466	=> "Hello, World!"
429		467
		468	=item $json = $json->allow_unknown ([$enable])
		469
		470	=item $enabled = $json->get_allow_unknown
		471
		472	If C<$enable> is true (or missing), then C<encode> will I<not> throw an
		473	exception when it encounters values it cannot represent in JSON (for
		474	example, filehandles) but instead will encode a JSON C<null> value. Note
		475	that blessed objects are not included here and are handled separately by
		476	c<allow_nonref>.
		477
		478	If C<$enable> is false (the default), then C<encode> will throw an
		479	exception when it encounters anything it cannot encode as JSON.
		480
		481	This option does not affect C<decode> in any way, and it is recommended to
		482	leave it off unless you know your communications partner.
		483
430	=item $json = $json->allow_blessed ([$enable])	484	=item $json = $json->allow_blessed ([$enable])
431		485
432	=item $enabled = $json->get_allow_bless	486	=item $enabled = $json->get_allow_blessed
433		487
434	If C<$enable> is true (or missing), then the C<encode> method will not	488	If C<$enable> is true (or missing), then the C<encode> method will not
435	barf when it encounters a blessed reference. Instead, the value of the	489	barf when it encounters a blessed reference. Instead, the value of the
436	B<convert_blessed> option will decide whether C<null> (C<convert_blessed>	490	B<convert_blessed> option will decide whether C<null> (C<convert_blessed>
437	disabled or no C<to_json> method found) or a representation of the	491	disabled or no C<TO_JSON> method found) or a representation of the
438	object (C<convert_blessed> enabled and C<to_json> method found) is being	492	object (C<convert_blessed> enabled and C<TO_JSON> method found) is being
439	encoded. Has no effect on C<decode>.	493	encoded. Has no effect on C<decode>.
440		494
441	If C<$enable> is false (the default), then C<encode> will throw an	495	If C<$enable> is false (the default), then C<encode> will throw an
442	exception when it encounters a blessed object.	496	exception when it encounters a blessed object.
443		497
…		…
455	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>	509	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>
456	returns other blessed objects, those will be handled in the same	510	returns other blessed objects, those will be handled in the same
457	way. C<TO_JSON> must take care of not causing an endless recursion cycle	511	way. C<TO_JSON> must take care of not causing an endless recursion cycle
458	(== crash) in this case. The name of C<TO_JSON> was chosen because other	512	(== crash) in this case. The name of C<TO_JSON> was chosen because other
459	methods called by the Perl core (== not by the user of the object) are	513	methods called by the Perl core (== not by the user of the object) are
460	usually in upper case letters and to avoid collisions with the C<to_json>	514	usually in upper case letters and to avoid collisions with any C<to_json>
461	function.	515	function or method.
462		516
463	This setting does not yet influence C<decode> in any way, but in the	517	This setting does not yet influence C<decode> in any way, but in the
464	future, global hooks might get installed that influence C<decode> and are	518	future, global hooks might get installed that influence C<decode> and are
465	enabled by this setting.	519	enabled by this setting.
466		520
…		…
574	=item $json = $json->max_depth ([$maximum_nesting_depth])	628	=item $json = $json->max_depth ([$maximum_nesting_depth])
575		629
576	=item $max_depth = $json->get_max_depth	630	=item $max_depth = $json->get_max_depth
577		631
578	Sets the maximum nesting level (default C<512>) accepted while encoding	632	Sets the maximum nesting level (default C<512>) accepted while encoding
579	or decoding. If the JSON text or Perl data structure has an equal or	633	or decoding. If a higher nesting level is detected in JSON text or a Perl
580	higher nesting level then this limit, then the encoder and decoder will	634	data structure, then the encoder and decoder will stop and croak at that
581	stop and croak at that point.	635	point.
582		636
583	Nesting level is defined by number of hash- or arrayrefs that the encoder	637	Nesting level is defined by number of hash- or arrayrefs that the encoder
584	needs to traverse to reach a given point or the number of C<{> or C<[>	638	needs to traverse to reach a given point or the number of C<{> or C<[>
585	characters without their matching closing parenthesis crossed to reach a	639	characters without their matching closing parenthesis crossed to reach a
586	given character in a string.	640	given character in a string.
587		641
588	Setting the maximum depth to one disallows any nesting, so that ensures	642	Setting the maximum depth to one disallows any nesting, so that ensures
589	that the object is only a single hash/object or array.	643	that the object is only a single hash/object or array.
590		644
591	The argument to C<max_depth> will be rounded up to the next highest power
592	of two. If no argument is given, the highest possible setting will be	645	If no argument is given, the highest possible setting will be used, which
593	used, which is rarely useful.	646	is rarely useful.
		647
		648	Note that nesting is implemented by recursion in C. The default value has
		649	been chosen to be as large as typical operating systems allow without
		650	crashing.
594		651
595	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.	652	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
596		653
597	=item $json = $json->max_size ([$maximum_string_size])	654	=item $json = $json->max_size ([$maximum_string_size])
598		655
599	=item $max_size = $json->get_max_size	656	=item $max_size = $json->get_max_size
600		657
601	Set the maximum length a JSON text may have (in bytes) where decoding is	658	Set the maximum length a JSON text may have (in bytes) where decoding is
602	being attempted. The default is C<0>, meaning no limit. When C<decode>	659	being attempted. The default is C<0>, meaning no limit. When C<decode>
603	is called on a string longer then this number of characters it will not	660	is called on a string that is longer then this many bytes, it will not
604	attempt to decode the string but throw an exception. This setting has no	661	attempt to decode the string but throw an exception. This setting has no
605	effect on C<encode> (yet).	662	effect on C<encode> (yet).
606		663
607	The argument to C<max_size> will be rounded up to the next B<highest>	664	If no argument is given, the limit check will be deactivated (same as when
608	power of two (so may be more than requested). If no argument is given, the	665	C<0> is specified).
609	limit check will be deactivated (same as when C<0> is specified).
610		666
611	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.	667	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
612		668
613	=item $json_text = $json->encode ($perl_scalar)	669	=item $json_text = $json->encode ($perl_scalar)
614		670
…		…
643	=> ([], 3)	699	=> ([], 3)
644		700
645	=back	701	=back
646		702
647		703
		704	=head1 INCREMENTAL PARSING
		705
		706	[This section and the API it details is still EXPERIMENTAL]
		707
		708	In some cases, there is the need for incremental parsing of JSON
		709	texts. While this module always has to keep both JSON text and resulting
		710	Perl data structure in memory at one time, it does allow you to parse a
		711	JSON stream incrementally. It does so by accumulating text until it has
		712	a full JSON object, which it then can decode. This process is similar to
		713	using C<decode_prefix> to see if a full JSON object is available, but is
		714	much more efficient (JSON::XS will only attempt to parse the JSON text
		715	once it is sure it has enough text to get a decisive result, using a very
		716	simple but truly incremental parser).
		717
		718	The following two methods deal with this.
		719
		720	=over 4
		721
		722	=item [void, scalar or list context] = $json->incr_parse ([$string])
		723
		724	This is the central parsing function. It can both append new text and
		725	extract objects from the stream accumulated so far (both of these
		726	functions are optional).
		727
		728	If C<$string> is given, then this string is appended to the already
		729	existing JSON fragment stored in the C<$json> object.
		730
		731	After that, if the function is called in void context, it will simply
		732	return without doing anything further. This can be used to add more text
		733	in as many chunks as you want.
		734
		735	If the method is called in scalar context, then it will try to extract
		736	exactly I<one> JSON object. If that is successful, it will return this
		737	object, otherwise it will return C<undef>. If there is a parse error,
		738	this method will croak just as C<decode> would do (one can then use
		739	C<incr_skip> to skip the errornous part). This is the most common way of
		740	using the method.
		741
		742	And finally, in list context, it will try to extract as many objects
		743	from the stream as it can find and return them, or the empty list
		744	otherwise. For this to work, there must be no separators between the JSON
		745	objects or arrays, instead they must be concatenated back-to-back. If
		746	an error occurs, an exception will be raised as in the scalar context
		747	case. Note that in this case, any previously-parsed JSON texts will be
		748	lost.
		749
		750	=item $lvalue_string = $json->incr_text
		751
		752	This method returns the currently stored JSON fragment as an lvalue, that
		753	is, you can manipulate it. This I<only> works when a preceding call to
		754	C<incr_parse> in I<scalar context> successfully returned an object. Under
		755	all other circumstances you must not call this function (I mean it.
		756	although in simple tests it might actually work, it I<will> fail under
		757	real world conditions). As a special exception, you can also call this
		758	method before having parsed anything.
		759
		760	This function is useful in two cases: a) finding the trailing text after a
		761	JSON object or b) parsing multiple JSON objects separated by non-JSON text
		762	(such as commas).
		763
		764	=item $json->incr_skip
		765
		766	This will reset the state of the incremental parser and will remove the
		767	parsed text from the input buffer. This is useful after C<incr_parse>
		768	died, in which case the input buffer and incremental parser state is left
		769	unchanged, to skip the text parsed so far and to reset the parse state.
		770
		771	=back
		772
		773	=head2 LIMITATIONS
		774
		775	All options that affect decoding are supported, except
		776	C<allow_nonref>. The reason for this is that it cannot be made to
		777	work sensibly: JSON objects and arrays are self-delimited, i.e. you can concatenate
		778	them back to back and still decode them perfectly. This does not hold true
		779	for JSON numbers, however.
		780
		781	For example, is the string C<1> a single JSON number, or is it simply the
		782	start of C<12>? Or is C<12> a single JSON number, or the concatenation
		783	of C<1> and C<2>? In neither case you can tell, and this is why JSON::XS
		784	takes the conservative route and disallows this case.
		785
		786	=head2 EXAMPLES
		787
		788	Some examples will make all this clearer. First, a simple example that
		789	works similarly to C<decode_prefix>: We want to decode the JSON object at
		790	the start of a string and identify the portion after the JSON object:
		791
		792	my $text = "[1,2,3] hello";
		793
		794	my $json = new JSON::XS;
		795
		796	my $obj = $json->incr_parse ($text)
		797	or die "expected JSON object or array at beginning of string";
		798
		799	my $tail = $json->incr_text;
		800	# $tail now contains " hello"
		801
		802	Easy, isn't it?
		803
		804	Now for a more complicated example: Imagine a hypothetical protocol where
		805	you read some requests from a TCP stream, and each request is a JSON
		806	array, without any separation between them (in fact, it is often useful to
		807	use newlines as "separators", as these get interpreted as whitespace at
		808	the start of the JSON text, which makes it possible to test said protocol
		809	with C<telnet>...).
		810
		811	Here is how you'd do it (it is trivial to write this in an event-based
		812	manner):
		813
		814	my $json = new JSON::XS;
		815
		816	# read some data from the socket
		817	while (sysread $socket, my $buf, 4096) {
		818
		819	# split and decode as many requests as possible
		820	for my $request ($json->incr_parse ($buf)) {
		821	# act on the $request
		822	}
		823	}
		824
		825	Another complicated example: Assume you have a string with JSON objects
		826	or arrays, all separated by (optional) comma characters (e.g. C<[1],[2],
		827	[3]>). To parse them, we have to skip the commas between the JSON texts,
		828	and here is where the lvalue-ness of C<incr_text> comes in useful:
		829
		830	my $text = "[1],[2], [3]";
		831	my $json = new JSON::XS;
		832
		833	# void context, so no parsing done
		834	$json->incr_parse ($text);
		835
		836	# now extract as many objects as possible. note the
		837	# use of scalar context so incr_text can be called.
		838	while (my $obj = $json->incr_parse) {
		839	# do something with $obj
		840
		841	# now skip the optional comma
		842	$json->incr_text =~ s/^ \s* , //x;
		843	}
		844
		845	Now lets go for a very complex example: Assume that you have a gigantic
		846	JSON array-of-objects, many gigabytes in size, and you want to parse it,
		847	but you cannot load it into memory fully (this has actually happened in
		848	the real world :).
		849
		850	Well, you lost, you have to implement your own JSON parser. But JSON::XS
		851	can still help you: You implement a (very simple) array parser and let
		852	JSON decode the array elements, which are all full JSON objects on their
		853	own (this wouldn't work if the array elements could be JSON numbers, for
		854	example):
		855
		856	my $json = new JSON::XS;
		857
		858	# open the monster
		859	open my $fh, "<bigfile.json"
		860	or die "bigfile: $!";
		861
		862	# first parse the initial "["
		863	for (;;) {
		864	sysread $fh, my $buf, 65536
		865	or die "read error: $!";
		866	$json->incr_parse ($buf); # void context, so no parsing
		867
		868	# Exit the loop once we found and removed(!) the initial "[".
		869	# In essence, we are (ab-)using the $json object as a simple scalar
		870	# we append data to.
		871	last if $json->incr_text =~ s/^ \s* \[ //x;
		872	}
		873
		874	# now we have the skipped the initial "[", so continue
		875	# parsing all the elements.
		876	for (;;) {
		877	# in this loop we read data until we got a single JSON object
		878	for (;;) {
		879	if (my $obj = $json->incr_parse) {
		880	# do something with $obj
		881	last;
		882	}
		883
		884	# add more data
		885	sysread $fh, my $buf, 65536
		886	or die "read error: $!";
		887	$json->incr_parse ($buf); # void context, so no parsing
		888	}
		889
		890	# in this loop we read data until we either found and parsed the
		891	# separating "," between elements, or the final "]"
		892	for (;;) {
		893	# first skip whitespace
		894	$json->incr_text =~ s/^\s*//;
		895
		896	# if we find "]", we are done
		897	if ($json->incr_text =~ s/^\]//) {
		898	print "finished.\n";
		899	exit;
		900	}
		901
		902	# if we find ",", we can continue with the next element
		903	if ($json->incr_text =~ s/^,//) {
		904	last;
		905	}
		906
		907	# if we find anything else, we have a parse error!
		908	if (length $json->incr_text) {
		909	die "parse error near ", $json->incr_text;
		910	}
		911
		912	# else add more data
		913	sysread $fh, my $buf, 65536
		914	or die "read error: $!";
		915	$json->incr_parse ($buf); # void context, so no parsing
		916	}
		917
		918	This is a complex example, but most of the complexity comes from the fact
		919	that we are trying to be correct (bear with me if I am wrong, I never ran
		920	the above example :).
		921
		922
		923
648	=head1 MAPPING	924	=head1 MAPPING
649		925
650	This section describes how JSON::XS maps Perl values to JSON values and	926	This section describes how JSON::XS maps Perl values to JSON values and
651	vice versa. These mappings are designed to "do the right thing" in most	927	vice versa. These mappings are designed to "do the right thing" in most
652	circumstances automatically, preserving round-tripping characteristics	928	circumstances automatically, preserving round-tripping characteristics
…		…
680		956
681	A JSON number becomes either an integer, numeric (floating point) or	957	A JSON number becomes either an integer, numeric (floating point) or
682	string scalar in perl, depending on its range and any fractional parts. On	958	string scalar in perl, depending on its range and any fractional parts. On
683	the Perl level, there is no difference between those as Perl handles all	959	the Perl level, there is no difference between those as Perl handles all
684	the conversion details, but an integer may take slightly less memory and	960	the conversion details, but an integer may take slightly less memory and
685	might represent more values exactly than (floating point) numbers.	961	might represent more values exactly than floating point numbers.
686		962
687	If the number consists of digits only, JSON::XS will try to represent	963	If the number consists of digits only, JSON::XS will try to represent
688	it as an integer value. If that fails, it will try to represent it as	964	it as an integer value. If that fails, it will try to represent it as
689	a numeric (floating point) value if that is possible without loss of	965	a numeric (floating point) value if that is possible without loss of
690	precision. Otherwise it will preserve the number as a string value.	966	precision. Otherwise it will preserve the number as a string value (in
		967	which case you lose roundtripping ability, as the JSON number will be
		968	re-encoded toa JSON string).
691		969
692	Numbers containing a fractional or exponential part will always be	970	Numbers containing a fractional or exponential part will always be
693	represented as numeric (floating point) values, possibly at a loss of	971	represented as numeric (floating point) values, possibly at a loss of
694	precision.	972	precision (in which case you might lose perfect roundtripping ability, but
695		973	the JSON number will still be re-encoded as a JSON number).
696	This might create round-tripping problems as numbers might become strings,
697	but as Perl is typeless there is no other way to do it.
698		974
699	=item true, false	975	=item true, false
700		976
701	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,	977	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,
702	respectively. They are overloaded to act almost exactly like the numbers	978	respectively. They are overloaded to act almost exactly like the numbers
…		…
739	Other unblessed references are generally not allowed and will cause an	1015	Other unblessed references are generally not allowed and will cause an
740	exception to be thrown, except for references to the integers C<0> and	1016	exception to be thrown, except for references to the integers C<0> and
741	C<1>, which get turned into C<false> and C<true> atoms in JSON. You can	1017	C<1>, which get turned into C<false> and C<true> atoms in JSON. You can
742	also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability.	1018	also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability.
743		1019
744	to_json [\0,JSON::XS::true] # yields [false,true]	1020	encode_json [\0,JSON::XS::true] # yields [false,true]
745		1021
746	=item JSON::XS::true, JSON::XS::false	1022	=item JSON::XS::true, JSON::XS::false
747		1023
748	These special values become JSON true and JSON false values,	1024	These special values become JSON true and JSON false values,
749	respectively. You can also use C<\1> and C<\0> directly if you want.	1025	respectively. You can also use C<\1> and C<\0> directly if you want.
750		1026
751	=item blessed objects	1027	=item blessed objects
752		1028
753	Blessed objects are not allowed. JSON::XS currently tries to encode their	1029	Blessed objects are not directly representable in JSON. See the
754	underlying representation (hash- or arrayref), but this behaviour might	1030	C<allow_blessed> and C<convert_blessed> methods on various options on
755	change in future versions.	1031	how to deal with this: basically, you can choose between throwing an
		1032	exception, encoding the reference as if it weren't blessed, or provide
		1033	your own serialiser method.
756		1034
757	=item simple scalars	1035	=item simple scalars
758		1036
759	Simple Perl scalars (any scalar that is not a reference) are the most	1037	Simple Perl scalars (any scalar that is not a reference) are the most
760	difficult objects to encode: JSON::XS will encode undefined scalars as	1038	difficult objects to encode: JSON::XS will encode undefined scalars as
761	JSON null value, scalars that have last been used in a string context	1039	JSON C<null> values, scalars that have last been used in a string context
762	before encoding as JSON strings and anything else as number value:	1040	before encoding as JSON strings, and anything else as number value:
763		1041
764	# dump as number	1042	# dump as number
765	to_json [2] # yields [2]	1043	encode_json [2] # yields [2]
766	to_json [-3.0e17] # yields [-3e+17]	1044	encode_json [-3.0e17] # yields [-3e+17]
767	my $value = 5; to_json [$value] # yields [5]	1045	my $value = 5; encode_json [$value] # yields [5]
768		1046
769	# used as string, so dump as string	1047	# used as string, so dump as string
770	print $value;	1048	print $value;
771	to_json [$value] # yields ["5"]	1049	encode_json [$value] # yields ["5"]
772		1050
773	# undef becomes null	1051	# undef becomes null
774	to_json [undef] # yields [null]	1052	encode_json [undef] # yields [null]
775		1053
776	You can force the type to be a JSON string by stringifying it:	1054	You can force the type to be a JSON string by stringifying it:
777		1055
778	my $x = 3.1; # some variable containing a number	1056	my $x = 3.1; # some variable containing a number
779	"$x"; # stringified	1057	"$x"; # stringified
…		…
785	my $x = "3"; # some variable containing a string	1063	my $x = "3"; # some variable containing a string
786	$x += 0; # numify it, ensuring it will be dumped as a number	1064	$x += 0; # numify it, ensuring it will be dumped as a number
787	$x *= 1; # same thing, the choice is yours.	1065	$x *= 1; # same thing, the choice is yours.
788		1066
789	You can not currently force the type in other, less obscure, ways. Tell me	1067	You can not currently force the type in other, less obscure, ways. Tell me
790	if you need this capability.	1068	if you need this capability (but don't forget to explain why it's needed
		1069	:).
791		1070
792	=back	1071	=back
793		1072
794		1073
795	=head1 COMPARISON	1074	=head1 ENCODING/CODESET FLAG NOTES
796		1075
797	As already mentioned, this module was created because none of the existing	1076	The interested reader might have seen a number of flags that signify
798	JSON modules could be made to work correctly. First I will describe the	1077	encodings or codesets - C<utf8>, C<latin1> and C<ascii>. There seems to be
799	problems (or pleasures) I encountered with various existing JSON modules,	1078	some confusion on what these do, so here is a short comparison:
800	followed by some benchmark values. JSON::XS was designed not to suffer	1079
801	from any of these problems or limitations.	1080	C<utf8> controls whether the JSON text created by C<encode> (and expected
		1081	by C<decode>) is UTF-8 encoded or not, while C<latin1> and C<ascii> only
		1082	control whether C<encode> escapes character values outside their respective
		1083	codeset range. Neither of these flags conflict with each other, although
		1084	some combinations make less sense than others.
		1085
		1086	Care has been taken to make all flags symmetrical with respect to
		1087	C<encode> and C<decode>, that is, texts encoded with any combination of
		1088	these flag values will be correctly decoded when the same flags are used
		1089	- in general, if you use different flag settings while encoding vs. when
		1090	decoding you likely have a bug somewhere.
		1091
		1092	Below comes a verbose discussion of these flags. Note that a "codeset" is
		1093	simply an abstract set of character-codepoint pairs, while an encoding
		1094	takes those codepoint numbers and I<encodes> them, in our case into
		1095	octets. Unicode is (among other things) a codeset, UTF-8 is an encoding,
		1096	and ISO-8859-1 (= latin 1) and ASCII are both codesets I<and> encodings at
		1097	the same time, which can be confusing.
802		1098
803	=over 4	1099	=over 4
804		1100
805	=item JSON 1.07	1101	=item C<utf8> flag disabled
806		1102
807	Slow (but very portable, as it is written in pure Perl).	1103	When C<utf8> is disabled (the default), then C<encode>/C<decode> generate
		1104	and expect Unicode strings, that is, characters with high ordinal Unicode
		1105	values (> 255) will be encoded as such characters, and likewise such
		1106	characters are decoded as-is, no canges to them will be done, except
		1107	"(re-)interpreting" them as Unicode codepoints or Unicode characters,
		1108	respectively (to Perl, these are the same thing in strings unless you do
		1109	funny/weird/dumb stuff).
808		1110
809	Undocumented/buggy Unicode handling (how JSON handles Unicode values is	1111	This is useful when you want to do the encoding yourself (e.g. when you
810	undocumented. One can get far by feeding it Unicode strings and doing	1112	want to have UTF-16 encoded JSON texts) or when some other layer does
811	en-/decoding oneself, but Unicode escapes are not working properly).	1113	the encoding for you (for example, when printing to a terminal using a
		1114	filehandle that transparently encodes to UTF-8 you certainly do NOT want
		1115	to UTF-8 encode your data first and have Perl encode it another time).
812		1116
813	No round-tripping (strings get clobbered if they look like numbers, e.g.	1117	=item C<utf8> flag enabled
814	the string C<2.0> will encode to C<2.0> instead of C<"2.0">, and that will
815	decode into the number 2.
816		1118
817	=item JSON::PC 0.01	1119	If the C<utf8>-flag is enabled, C<encode>/C<decode> will encode all
		1120	characters using the corresponding UTF-8 multi-byte sequence, and will
		1121	expect your input strings to be encoded as UTF-8, that is, no "character"
		1122	of the input string must have any value > 255, as UTF-8 does not allow
		1123	that.
818		1124
819	Very fast.	1125	The C<utf8> flag therefore switches between two modes: disabled means you
		1126	will get a Unicode string in Perl, enabled means you get an UTF-8 encoded
		1127	octet/binary string in Perl.
820		1128
821	Undocumented/buggy Unicode handling.	1129	=item C<latin1> or C<ascii> flags enabled
822		1130
823	No round-tripping.	1131	With C<latin1> (or C<ascii>) enabled, C<encode> will escape characters
		1132	with ordinal values > 255 (> 127 with C<ascii>) and encode the remaining
		1133	characters as specified by the C<utf8> flag.
824		1134
825	Has problems handling many Perl values (e.g. regex results and other magic	1135	If C<utf8> is disabled, then the result is also correctly encoded in those
826	values will make it croak).	1136	character sets (as both are proper subsets of Unicode, meaning that a
		1137	Unicode string with all character values < 256 is the same thing as a
		1138	ISO-8859-1 string, and a Unicode string with all character values < 128 is
		1139	the same thing as an ASCII string in Perl).
827		1140
828	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>	1141	If C<utf8> is enabled, you still get a correct UTF-8-encoded string,
829	which is not a valid JSON text.	1142	regardless of these flags, just some more characters will be escaped using
		1143	C<\uXXXX> then before.
830		1144
831	Unmaintained (maintainer unresponsive for many months, bugs are not	1145	Note that ISO-8859-1-I<encoded> strings are not compatible with UTF-8
832	getting fixed).	1146	encoding, while ASCII-encoded strings are. That is because the ISO-8859-1
		1147	encoding is NOT a subset of UTF-8 (despite the ISO-8859-1 I<codeset> being
		1148	a subset of Unicode), while ASCII is.
833		1149
834	=item JSON::Syck 0.21	1150	Surprisingly, C<decode> will ignore these flags and so treat all input
		1151	values as governed by the C<utf8> flag. If it is disabled, this allows you
		1152	to decode ISO-8859-1- and ASCII-encoded strings, as both strict subsets of
		1153	Unicode. If it is enabled, you can correctly decode UTF-8 encoded strings.
835		1154
836	Very buggy (often crashes).	1155	So neither C<latin1> nor C<ascii> are incompatible with the C<utf8> flag -
		1156	they only govern when the JSON output engine escapes a character or not.
837		1157
838	Very inflexible (no human-readable format supported, format pretty much	1158	The main use for C<latin1> is to relatively efficiently store binary data
839	undocumented. I need at least a format for easy reading by humans and a	1159	as JSON, at the expense of breaking compatibility with most JSON decoders.
840	single-line compact format for use in a protocol, and preferably a way to
841	generate ASCII-only JSON texts).
842		1160
843	Completely broken (and confusingly documented) Unicode handling (Unicode	1161	The main use for C<ascii> is to force the output to not contain characters
844	escapes are not working properly, you need to set ImplicitUnicode to	1162	with values > 127, which means you can interpret the resulting string
845	I<different> values on en- and decoding to get symmetric behaviour).	1163	as UTF-8, ISO-8859-1, ASCII, KOI8-R or most about any character set and
846		1164	8-bit-encoding, and still get the same data structure back. This is useful
847	No round-tripping (simple cases work, but this depends on whether the scalar	1165	when your channel for JSON transfer is not 8-bit clean or the encoding
848	value was used in a numeric context or not).	1166	might be mangled in between (e.g. in mail), and works because ASCII is a
849		1167	proper subset of most 8-bit and multibyte encodings in use in the world.
850	Dumping hashes may skip hash values depending on iterator state.
851
852	Unmaintained (maintainer unresponsive for many months, bugs are not
853	getting fixed).
854
855	Does not check input for validity (i.e. will accept non-JSON input and
856	return "something" instead of raising an exception. This is a security
857	issue: imagine two banks transferring money between each other using
858	JSON. One bank might parse a given non-JSON request and deduct money,
859	while the other might reject the transaction with a syntax error. While a
860	good protocol will at least recover, that is extra unnecessary work and
861	the transaction will still not succeed).
862
863	=item JSON::DWIW 0.04
864
865	Very fast. Very natural. Very nice.
866
867	Undocumented Unicode handling (but the best of the pack. Unicode escapes
868	still don't get parsed properly).
869
870	Very inflexible.
871
872	No round-tripping.
873
874	Does not generate valid JSON texts (key strings are often unquoted, empty keys
875	result in nothing being output)
876
877	Does not check input for validity.
878		1168
879	=back	1169	=back
880		1170
881		1171
882	=head2 JSON and YAML	1172	=head2 JSON and YAML
883		1173
884	You often hear that JSON is a subset (or a close subset) of YAML. This is,	1174	You often hear that JSON is a subset of YAML. This is, however, a mass
885	however, a mass hysteria and very far from the truth. In general, there is	1175	hysteria(*) and very far from the truth (as of the time of this writing),
886	no way to configure JSON::XS to output a data structure as valid YAML.	1176	so let me state it clearly: I<in general, there is no way to configure
		1177	JSON::XS to output a data structure as valid YAML> that works in all
		1178	cases.
887		1179
888	If you really must use JSON::XS to generate YAML, you should use this	1180	If you really must use JSON::XS to generate YAML, you should use this
889	algorithm (subject to change in future versions):	1181	algorithm (subject to change in future versions):
890		1182
891	my $to_yaml = JSON::XS->new->utf8->space_after (1);	1183	my $to_yaml = JSON::XS->new->utf8->space_after (1);
892	my $yaml = $to_yaml->encode ($ref) . "\n";	1184	my $yaml = $to_yaml->encode ($ref) . "\n";
893		1185
894	This will usually generate JSON texts that also parse as valid	1186	This will I<usually> generate JSON texts that also parse as valid
895	YAML. Please note that YAML has hardcoded limits on (simple) object key	1187	YAML. Please note that YAML has hardcoded limits on (simple) object key
896	lengths that JSON doesn't have, so you should make sure that your hash	1188	lengths that JSON doesn't have and also has different and incompatible
		1189	unicode handling, so you should make sure that your hash keys are
897	keys are noticeably shorter than the 1024 characters YAML allows.	1190	noticeably shorter than the 1024 "stream characters" YAML allows and that
		1191	you do not have characters with codepoint values outside the Unicode BMP
		1192	(basic multilingual page). YAML also does not allow C<\/> sequences in
		1193	strings (which JSON::XS does not I<currently> generate, but other JSON
		1194	generators might).
898		1195
899	There might be other incompatibilities that I am not aware of. In general	1196	There might be other incompatibilities that I am not aware of (or the YAML
		1197	specification has been changed yet again - it does so quite often). In
900	you should not try to generate YAML with a JSON generator or vice versa,	1198	general you should not try to generate YAML with a JSON generator or vice
901	or try to parse JSON with a YAML parser or vice versa: chances are high	1199	versa, or try to parse JSON with a YAML parser or vice versa: chances are
902	that you will run into severe interoperability problems.	1200	high that you will run into severe interoperability problems when you
		1201	least expect it.
		1202
		1203	=over 4
		1204
		1205	=item (*)
		1206
		1207	I have been pressured multiple times by Brian Ingerson (one of the
		1208	authors of the YAML specification) to remove this paragraph, despite him
		1209	acknowledging that the actual incompatibilities exist. As I was personally
		1210	bitten by this "JSON is YAML" lie, I refused and said I will continue to
		1211	educate people about these issues, so others do not run into the same
		1212	problem again and again. After this, Brian called me a (quote)I<complete
		1213	and worthless idiot>(unquote).
		1214
		1215	In my opinion, instead of pressuring and insulting people who actually
		1216	clarify issues with YAML and the wrong statements of some of its
		1217	proponents, I would kindly suggest reading the JSON spec (which is not
		1218	that difficult or long) and finally make YAML compatible to it, and
		1219	educating users about the changes, instead of spreading lies about the
		1220	real compatibility for many I<years> and trying to silence people who
		1221	point out that it isn't true.
		1222
		1223	=back
903		1224
904		1225
905	=head2 SPEED	1226	=head2 SPEED
906		1227
907	It seems that JSON::XS is surprisingly fast, as shown in the following	1228	It seems that JSON::XS is surprisingly fast, as shown in the following
908	tables. They have been generated with the help of the C<eg/bench> program	1229	tables. They have been generated with the help of the C<eg/bench> program
909	in the JSON::XS distribution, to make it easy to compare on your own	1230	in the JSON::XS distribution, to make it easy to compare on your own
910	system.	1231	system.
911		1232
912	First comes a comparison between various modules using a very short	1233	First comes a comparison between various modules using
913	single-line JSON string:	1234	a very short single-line JSON string (also available at
		1235	L<http://dist.schmorp.de/misc/json/short.json>).
914		1236
915	{"method": "handleMessage", "params": ["user1", "we were just talking"], \	1237	{"method": "handleMessage", "params": ["user1",
916	"id": null, "array":[1,11,234,-5,1e5,1e7, true, false]}	1238	"we were just talking"], "id": null, "array":[1,11,234,-5,1e5,1e7,
		1239	true, false]}
917		1240
918	It shows the number of encodes/decodes per second (JSON::XS uses	1241	It shows the number of encodes/decodes per second (JSON::XS uses
919	the functional interface, while JSON::XS/2 uses the OO interface	1242	the functional interface, while JSON::XS/2 uses the OO interface
920	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables	1243	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables
921	shrink). Higher is better:	1244	shrink). Higher is better:
…		…
937	about three times faster on decoding, and over forty times faster	1260	about three times faster on decoding, and over forty times faster
938	than JSON, even with pretty-printing and key sorting. It also compares	1261	than JSON, even with pretty-printing and key sorting. It also compares
939	favourably to Storable for small amounts of data.	1262	favourably to Storable for small amounts of data.
940		1263
941	Using a longer test string (roughly 18KB, generated from Yahoo! Locals	1264	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
942	search API (http://nanoref.com/yahooapis/mgPdGg):	1265	search API (L<http://dist.schmorp.de/misc/json/long.json>).
943		1266
944	module \| encode \| decode \|	1267	module \| encode \| decode \|
945	-----------\|------------\|------------\|	1268	-----------\|------------\|------------\|
946	JSON 1.x \| 55.260 \| 34.971 \|	1269	JSON 1.x \| 55.260 \| 34.971 \|
947	JSON::DWIW \| 825.228 \| 1082.513 \|	1270	JSON::DWIW \| 825.228 \| 1082.513 \|
…		…
984		1307
985	Third, JSON::XS recurses using the C stack when decoding objects and	1308	Third, JSON::XS recurses using the C stack when decoding objects and
986	arrays. The C stack is a limited resource: for instance, on my amd64	1309	arrays. The C stack is a limited resource: for instance, on my amd64
987	machine with 8MB of stack size I can decode around 180k nested arrays but	1310	machine with 8MB of stack size I can decode around 180k nested arrays but
988	only 14k nested JSON objects (due to perl itself recursing deeply on croak	1311	only 14k nested JSON objects (due to perl itself recursing deeply on croak
989	to free the temporary). If that is exceeded, the program crashes. to be	1312	to free the temporary). If that is exceeded, the program crashes. To be
990	conservative, the default nesting limit is set to 512. If your process	1313	conservative, the default nesting limit is set to 512. If your process
991	has a smaller stack, you should adjust this setting accordingly with the	1314	has a smaller stack, you should adjust this setting accordingly with the
992	C<max_depth> method.	1315	C<max_depth> method.
993		1316
994	And last but least, something else could bomb you that I forgot to think	1317	Something else could bomb you, too, that I forgot to think of. In that
995	of. In that case, you get to keep the pieces. I am always open for hints,	1318	case, you get to keep the pieces. I am always open for hints, though...
996	though...	1319
		1320	Also keep in mind that JSON::XS might leak contents of your Perl data
		1321	structures in its error messages, so when you serialise sensitive
		1322	information you might want to make sure that exceptions thrown by JSON::XS
		1323	will not end up in front of untrusted eyes.
997		1324
998	If you are using JSON::XS to return packets to consumption	1325	If you are using JSON::XS to return packets to consumption
999	by JavaScript scripts in a browser you should have a look at	1326	by JavaScript scripts in a browser you should have a look at
1000	L<http://jpsykes.com/47/practical-csrf-and-json-security> to see whether	1327	L<http://jpsykes.com/47/practical-csrf-and-json-security> to see whether
1001	you are vulnerable to some common attack vectors (which really are browser	1328	you are vulnerable to some common attack vectors (which really are browser
1002	design bugs, but it is still you who will have to deal with it, as major	1329	design bugs, but it is still you who will have to deal with it, as major
1003	browser developers care only for features, not about doing security	1330	browser developers care only for features, not about getting security
1004	right).	1331	right).
1005		1332
1006		1333
1007	=head1 THREADS	1334	=head1 THREADS
1008		1335
1009	This module is I<not> guaranteed to be thread safe and there are no	1336	This module is I<not> guaranteed to be thread safe and there are no
1010	plans to change this until Perl gets thread support (as opposed to the	1337	plans to change this until Perl gets thread support (as opposed to the
1011	horribly slow so-called "threads" which are simply slow and bloated	1338	horribly slow so-called "threads" which are simply slow and bloated
1012	process simulations - use fork, its I<much> faster, cheaper, better).	1339	process simulations - use fork, it's I<much> faster, cheaper, better).
1013		1340
1014	(It might actually work, but you have been warned).	1341	(It might actually work, but you have been warned).
1015		1342
1016		1343
1017	=head1 BUGS	1344	=head1 BUGS
1018		1345
1019	While the goal of this module is to be correct, that unfortunately does	1346	While the goal of this module is to be correct, that unfortunately does
1020	not mean its bug-free, only that I think its design is bug-free. It is	1347	not mean it's bug-free, only that I think its design is bug-free. If you
1021	still relatively early in its development. If you keep reporting bugs they	1348	keep reporting bugs they will be fixed swiftly, though.
1022	will be fixed swiftly, though.
1023		1349
1024	Please refrain from using rt.cpan.org or any other bug reporting	1350	Please refrain from using rt.cpan.org or any other bug reporting
1025	service. I put the contact address into my modules for a reason.	1351	service. I put the contact address into my modules for a reason.
1026		1352
1027	=cut	1353	=cut
…		…
1047	"--" => sub { $_[0] = ${$_[0]} - 1 },	1373	"--" => sub { $_[0] = ${$_[0]} - 1 },
1048	fallback => 1;	1374	fallback => 1;
1049		1375
1050	1;	1376	1;
1051		1377
		1378	=head1 SEE ALSO
		1379
		1380	The F<json_xs> command line utility for quick experiments.
		1381
1052	=head1 AUTHOR	1382	=head1 AUTHOR
1053		1383
1054	Marc Lehmann <schmorp@schmorp.de>	1384	Marc Lehmann <schmorp@schmorp.de>
1055	http://home.schmorp.de/	1385	http://home.schmorp.de/
1056		1386

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Comparing JSON-XS/XS.pm (file contents): Revision 1.74 by root, Wed Nov 28 13:57:15 2007 UTC vs. Revision 1.103 by root, Tue Apr 29 16:07:56 2008 UTC

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Comparing JSON-XS/XS.pm (file contents):
Revision 1.74 by root, Wed Nov 28 13:57:15 2007 UTC vs.
Revision 1.103 by root, Tue Apr 29 16:07:56 2008 UTC