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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.108 by root, Tue Jul 15 11:29:29 2008 UTC vs.
Revision 1.120 by root, Sat May 30 06:26:05 2009 UTC

…		…
49	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
50	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
51	their maintainers are unresponsive, gone missing, or not listening to bug	51	their maintainers are unresponsive, gone missing, or not listening to bug
52	reports for other reasons.	52	reports for other reasons.
53		53
54	See COMPARISON, below, for a comparison to some other JSON modules.
55
56	See MAPPING, below, on how JSON::XS maps perl values to JSON values and	54	See MAPPING, below, on how JSON::XS maps perl values to JSON values and
57	vice versa.	55	vice versa.
58		56
59	=head2 FEATURES	57	=head2 FEATURES
60		58
…		…
101		99
102	=cut	100	=cut
103		101
104	package JSON::XS;	102	package JSON::XS;
105		103
		104	no warnings;
106	use strict;	105	use strict;
107		106
108	our $VERSION = '2.22';	107	our $VERSION = '2.24';
109	our @ISA = qw(Exporter);	108	our @ISA = qw(Exporter);
110		109
111	our @EXPORT = qw(encode_json decode_json to_json from_json);	110	our @EXPORT = qw(encode_json decode_json to_json from_json);
112		111
113	sub to_json($) {	112	sub to_json($) {
…		…
767	JSON object or b) parsing multiple JSON objects separated by non-JSON text	766	JSON object or b) parsing multiple JSON objects separated by non-JSON text
768	(such as commas).	767	(such as commas).
769		768
770	=item $json->incr_skip	769	=item $json->incr_skip
771		770
772	This will reset the state of the incremental parser and will remove the	771	This will reset the state of the incremental parser and will remove
773	parsed text from the input buffer. This is useful after C<incr_parse>	772	the parsed text from the input buffer so far. This is useful after
774	died, in which case the input buffer and incremental parser state is left	773	C<incr_parse> died, in which case the input buffer and incremental parser
775	unchanged, to skip the text parsed so far and to reset the parse state.	774	state is left unchanged, to skip the text parsed so far and to reset the
		775	parse state.
		776
		777	The difference to C<incr_reset> is that only text until the parse error
		778	occured is removed.
776		779
777	=item $json->incr_reset	780	=item $json->incr_reset
778		781
779	This completely resets the incremental parser, that is, after this call,	782	This completely resets the incremental parser, that is, after this call,
780	it will be as if the parser had never parsed anything.	783	it will be as if the parser had never parsed anything.
781		784
782	This is useful if you want ot repeatedly parse JSON objects and want to	785	This is useful if you want to repeatedly parse JSON objects and want to
783	ignore any trailing data, which means you have to reset the parser after	786	ignore any trailing data, which means you have to reset the parser after
784	each successful decode.	787	each successful decode.
785		788
786	=back	789	=back
787		790
…		…
1180	when your channel for JSON transfer is not 8-bit clean or the encoding	1183	when your channel for JSON transfer is not 8-bit clean or the encoding
1181	might be mangled in between (e.g. in mail), and works because ASCII is a	1184	might be mangled in between (e.g. in mail), and works because ASCII is a
1182	proper subset of most 8-bit and multibyte encodings in use in the world.	1185	proper subset of most 8-bit and multibyte encodings in use in the world.
1183		1186
1184	=back	1187	=back
		1188
		1189
		1190	=head2 JSON and ECMAscript
		1191
		1192	JSON syntax is based on how literals are represented in javascript (the
		1193	not-standardised predecessor of ECMAscript) which is presumably why it is
		1194	called "JavaScript Object Notation".
		1195
		1196	However, JSON is not a subset (and also not a superset of course) of
		1197	ECMAscript (the standard) or javascript (whatever browsers actually
		1198	implement).
		1199
		1200	If you want to use javascript's C<eval> function to "parse" JSON, you
		1201	might run into parse errors for valid JSON texts, or the resulting data
		1202	structure might not be queryable:
		1203
		1204	One of the problems is that U+2028 and U+2029 are valid characters inside
		1205	JSON strings, but are not allowed in ECMAscript string literals, so the
		1206	following Perl fragment will not output something that can be guaranteed
		1207	to be parsable by javascript's C<eval>:
		1208
		1209	use JSON::XS;
		1210
		1211	print encode_json [chr 0x2028];
		1212
		1213	The right fix for this is to use a proper JSON parser in your javascript
		1214	programs, and not rely on C<eval> (see for example Douglas Crockford's
		1215	F<json2.js> parser).
		1216
		1217	If this is not an option, you can, as a stop-gap measure, simply encode to
		1218	ASCII-only JSON:
		1219
		1220	use JSON::XS;
		1221
		1222	print JSON::XS->new->ascii->encode ([chr 0x2028]);
		1223
		1224	Note that this will enlarge the resulting JSON text quite a bit if you
		1225	have many non-ASCII characters. You might be tempted to run some regexes
		1226	to only escape U+2028 and U+2029, e.g.:
		1227
		1228	# DO NOT USE THIS!
		1229	my $json = JSON::XS->new->utf8->encode ([chr 0x2028]);
		1230	$json =~ s/\xe2\x80\xa8/\\u2028/g; # escape U+2028
		1231	$json =~ s/\xe2\x80\xa9/\\u2029/g; # escape U+2029
		1232	print $json;
		1233
		1234	Note that I<this is a bad idea>: the above only works for U+2028 and
		1235	U+2029 and thus only for fully ECMAscript-compliant parsers. Many existing
		1236	javascript implementations, however, have issues with other characters as
		1237	well - using C<eval> naively simply I<will> cause problems.
		1238
		1239	Another problem is that some javascript implementations reserve
		1240	some property names for their own purposes (which probably makes
		1241	them non-ECMAscript-compliant). For example, Iceweasel reserves the
		1242	C<__proto__> property name for it's own purposes.
		1243
		1244	If that is a problem, you could parse try to filter the resulting JSON
		1245	output for these property strings, e.g.:
		1246
		1247	$json =~ s/"__proto__"\s*:/"__proto__renamed":/g;
		1248
		1249	This works because C<__proto__> is not valid outside of strings, so every
		1250	occurence of C<"__proto__"\s*:> must be a string used as property name.
		1251
		1252	If you know of other incompatibilities, please let me know.
1185		1253
1186		1254
1187	=head2 JSON and YAML	1255	=head2 JSON and YAML
1188		1256
1189	You often hear that JSON is a subset of YAML. This is, however, a mass	1257	You often hear that JSON is a subset of YAML. This is, however, a mass

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Comparing JSON-XS/XS.pm (file contents): Revision 1.108 by root, Tue Jul 15 11:29:29 2008 UTC vs. Revision 1.120 by root, Sat May 30 06:26:05 2009 UTC

Diff Legend

Comparing JSON-XS/XS.pm (file contents):
Revision 1.108 by root, Tue Jul 15 11:29:29 2008 UTC vs.
Revision 1.120 by root, Sat May 30 06:26:05 2009 UTC