… | |
… | |
83 | this module usually compares favourably in terms of speed, too. |
83 | this module usually compares favourably in terms of speed, too. |
84 | |
84 | |
85 | =item * simple to use |
85 | =item * simple to use |
86 | |
86 | |
87 | This module has both a simple functional interface as well as an object |
87 | This module has both a simple functional interface as well as an object |
88 | oriented interface interface. |
88 | oriented interface. |
89 | |
89 | |
90 | =item * reasonably versatile output formats |
90 | =item * reasonably versatile output formats |
91 | |
91 | |
92 | You can choose between the most compact guaranteed-single-line format |
92 | You can choose between the most compact guaranteed-single-line format |
93 | possible (nice for simple line-based protocols), a pure-ASCII format |
93 | possible (nice for simple line-based protocols), a pure-ASCII format |
… | |
… | |
104 | use common::sense; |
104 | use common::sense; |
105 | |
105 | |
106 | our $VERSION = 2.34; |
106 | our $VERSION = 2.34; |
107 | our @ISA = qw(Exporter); |
107 | our @ISA = qw(Exporter); |
108 | |
108 | |
109 | our @EXPORT = qw(encode_json decode_json to_json from_json); |
109 | our @EXPORT = qw(encode_json decode_json); |
110 | |
|
|
111 | sub to_json($) { |
|
|
112 | require Carp; |
|
|
113 | 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"); |
|
|
114 | } |
|
|
115 | |
|
|
116 | sub from_json($) { |
|
|
117 | require Carp; |
|
|
118 | 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"); |
|
|
119 | } |
|
|
120 | |
110 | |
121 | use Exporter; |
111 | use Exporter; |
122 | use XSLoader; |
112 | use XSLoader; |
|
|
113 | |
|
|
114 | use Types::Serialiser (); |
123 | |
115 | |
124 | =head1 FUNCTIONAL INTERFACE |
116 | =head1 FUNCTIONAL INTERFACE |
125 | |
117 | |
126 | The following convenience methods are provided by this module. They are |
118 | The following convenience methods are provided by this module. They are |
127 | exported by default: |
119 | exported by default: |
… | |
… | |
148 | This function call is functionally identical to: |
140 | This function call is functionally identical to: |
149 | |
141 | |
150 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
142 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
151 | |
143 | |
152 | Except being faster. |
144 | Except being faster. |
153 | |
|
|
154 | =item $is_boolean = JSON::XS::is_bool $scalar |
|
|
155 | |
|
|
156 | Returns true if the passed scalar represents either JSON::XS::true or |
|
|
157 | JSON::XS::false, two constants that act like C<1> and C<0>, respectively |
|
|
158 | and are used to represent JSON C<true> and C<false> values in Perl. |
|
|
159 | |
|
|
160 | See MAPPING, below, for more information on how JSON values are mapped to |
|
|
161 | Perl. |
|
|
162 | |
145 | |
163 | =back |
146 | =back |
164 | |
147 | |
165 | |
148 | |
166 | =head1 A FEW NOTES ON UNICODE AND PERL |
149 | =head1 A FEW NOTES ON UNICODE AND PERL |
… | |
… | |
667 | |
650 | |
668 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
651 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
669 | |
652 | |
670 | =item $json_text = $json->encode ($perl_scalar) |
653 | =item $json_text = $json->encode ($perl_scalar) |
671 | |
654 | |
672 | Converts the given Perl data structure (a simple scalar or a reference |
655 | Converts the given Perl value or data structure to its JSON |
673 | to a hash or array) to its JSON representation. Simple scalars will be |
656 | representation. Croaks on error. |
674 | converted into JSON string or number sequences, while references to arrays |
|
|
675 | become JSON arrays and references to hashes become JSON objects. Undefined |
|
|
676 | Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true> |
|
|
677 | nor C<false> values will be generated. |
|
|
678 | |
657 | |
679 | =item $perl_scalar = $json->decode ($json_text) |
658 | =item $perl_scalar = $json->decode ($json_text) |
680 | |
659 | |
681 | The opposite of C<encode>: expects a JSON text and tries to parse it, |
660 | The opposite of C<encode>: expects a JSON text and tries to parse it, |
682 | returning the resulting simple scalar or reference. Croaks on error. |
661 | returning the resulting simple scalar or reference. Croaks on error. |
683 | |
|
|
684 | JSON numbers and strings become simple Perl scalars. JSON arrays become |
|
|
685 | Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes |
|
|
686 | C<1>, C<false> becomes C<0> and C<null> becomes C<undef>. |
|
|
687 | |
662 | |
688 | =item ($perl_scalar, $characters) = $json->decode_prefix ($json_text) |
663 | =item ($perl_scalar, $characters) = $json->decode_prefix ($json_text) |
689 | |
664 | |
690 | This works like the C<decode> method, but instead of raising an exception |
665 | This works like the C<decode> method, but instead of raising an exception |
691 | when there is trailing garbage after the first JSON object, it will |
666 | when there is trailing garbage after the first JSON object, it will |
692 | silently stop parsing there and return the number of characters consumed |
667 | silently stop parsing there and return the number of characters consumed |
693 | so far. |
668 | so far. |
694 | |
669 | |
695 | This is useful if your JSON texts are not delimited by an outer protocol |
670 | This is useful if your JSON texts are not delimited by an outer protocol |
696 | (which is not the brightest thing to do in the first place) and you need |
|
|
697 | to know where the JSON text ends. |
671 | and you need to know where the JSON text ends. |
698 | |
672 | |
699 | JSON::XS->new->decode_prefix ("[1] the tail") |
673 | JSON::XS->new->decode_prefix ("[1] the tail") |
700 | => ([], 3) |
674 | => ([], 3) |
701 | |
675 | |
702 | =back |
676 | =back |
… | |
… | |
741 | |
715 | |
742 | If the method is called in scalar context, then it will try to extract |
716 | If the method is called in scalar context, then it will try to extract |
743 | exactly I<one> JSON object. If that is successful, it will return this |
717 | exactly I<one> JSON object. If that is successful, it will return this |
744 | object, otherwise it will return C<undef>. If there is a parse error, |
718 | object, otherwise it will return C<undef>. If there is a parse error, |
745 | this method will croak just as C<decode> would do (one can then use |
719 | this method will croak just as C<decode> would do (one can then use |
746 | C<incr_skip> to skip the errornous part). This is the most common way of |
720 | C<incr_skip> to skip the erroneous part). This is the most common way of |
747 | using the method. |
721 | using the method. |
748 | |
722 | |
749 | And finally, in list context, it will try to extract as many objects |
723 | And finally, in list context, it will try to extract as many objects |
750 | from the stream as it can find and return them, or the empty list |
724 | from the stream as it can find and return them, or the empty list |
751 | otherwise. For this to work, there must be no separators between the JSON |
725 | otherwise. For this to work, there must be no separators between the JSON |
… | |
… | |
780 | C<incr_parse> died, in which case the input buffer and incremental parser |
754 | C<incr_parse> died, in which case the input buffer and incremental parser |
781 | state is left unchanged, to skip the text parsed so far and to reset the |
755 | state is left unchanged, to skip the text parsed so far and to reset the |
782 | parse state. |
756 | parse state. |
783 | |
757 | |
784 | The difference to C<incr_reset> is that only text until the parse error |
758 | The difference to C<incr_reset> is that only text until the parse error |
785 | occured is removed. |
759 | occurred is removed. |
786 | |
760 | |
787 | =item $json->incr_reset |
761 | =item $json->incr_reset |
788 | |
762 | |
789 | This completely resets the incremental parser, that is, after this call, |
763 | This completely resets the incremental parser, that is, after this call, |
790 | it will be as if the parser had never parsed anything. |
764 | it will be as if the parser had never parsed anything. |
… | |
… | |
796 | =back |
770 | =back |
797 | |
771 | |
798 | =head2 LIMITATIONS |
772 | =head2 LIMITATIONS |
799 | |
773 | |
800 | All options that affect decoding are supported, except |
774 | All options that affect decoding are supported, except |
801 | C<allow_nonref>. The reason for this is that it cannot be made to |
775 | C<allow_nonref>. The reason for this is that it cannot be made to work |
802 | work sensibly: JSON objects and arrays are self-delimited, i.e. you can concatenate |
776 | sensibly: JSON objects and arrays are self-delimited, i.e. you can |
803 | them back to back and still decode them perfectly. This does not hold true |
777 | concatenate them back to back and still decode them perfectly. This does |
804 | for JSON numbers, however. |
778 | not hold true for JSON numbers, however. |
805 | |
779 | |
806 | For example, is the string C<1> a single JSON number, or is it simply the |
780 | For example, is the string C<1> a single JSON number, or is it simply the |
807 | start of C<12>? Or is C<12> a single JSON number, or the concatenation |
781 | start of C<12>? Or is C<12> a single JSON number, or the concatenation |
808 | of C<1> and C<2>? In neither case you can tell, and this is why JSON::XS |
782 | of C<1> and C<2>? In neither case you can tell, and this is why JSON::XS |
809 | takes the conservative route and disallows this case. |
783 | takes the conservative route and disallows this case. |
… | |
… | |
988 | If the number consists of digits only, JSON::XS will try to represent |
962 | If the number consists of digits only, JSON::XS will try to represent |
989 | it as an integer value. If that fails, it will try to represent it as |
963 | it as an integer value. If that fails, it will try to represent it as |
990 | a numeric (floating point) value if that is possible without loss of |
964 | a numeric (floating point) value if that is possible without loss of |
991 | precision. Otherwise it will preserve the number as a string value (in |
965 | precision. Otherwise it will preserve the number as a string value (in |
992 | which case you lose roundtripping ability, as the JSON number will be |
966 | which case you lose roundtripping ability, as the JSON number will be |
993 | re-encoded toa JSON string). |
967 | re-encoded to a JSON string). |
994 | |
968 | |
995 | Numbers containing a fractional or exponential part will always be |
969 | Numbers containing a fractional or exponential part will always be |
996 | represented as numeric (floating point) values, possibly at a loss of |
970 | represented as numeric (floating point) values, possibly at a loss of |
997 | precision (in which case you might lose perfect roundtripping ability, but |
971 | precision (in which case you might lose perfect roundtripping ability, but |
998 | the JSON number will still be re-encoded as a JSON number). |
972 | the JSON number will still be re-encoded as a JSON number). |
999 | |
973 | |
1000 | Note that precision is not accuracy - binary floating point values cannot |
974 | Note that precision is not accuracy - binary floating point values cannot |
1001 | represent most decimal fractions exactly, and when converting from and to |
975 | represent most decimal fractions exactly, and when converting from and to |
1002 | floating point, JSON::XS only guarantees precision up to but not including |
976 | floating point, JSON::XS only guarantees precision up to but not including |
1003 | the leats significant bit. |
977 | the least significant bit. |
1004 | |
978 | |
1005 | =item true, false |
979 | =item true, false |
1006 | |
980 | |
1007 | These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>, |
981 | These JSON atoms become C<Types::Serialiser::true> and |
1008 | respectively. They are overloaded to act almost exactly like the numbers |
982 | C<Types::Serialiser::false>, respectively. They are overloaded to act |
1009 | C<1> and C<0>. You can check whether a scalar is a JSON boolean by using |
983 | almost exactly like the numbers C<1> and C<0>. You can check whether |
1010 | the C<JSON::XS::is_bool> function. |
984 | a scalar is a JSON boolean by using the C<Types::Serialiser::is_bool> |
|
|
985 | function (after C<use Types::Serialier>, of course). |
1011 | |
986 | |
1012 | =item null |
987 | =item null |
1013 | |
988 | |
1014 | A JSON null atom becomes C<undef> in Perl. |
989 | A JSON null atom becomes C<undef> in Perl. |
1015 | |
990 | |
… | |
… | |
1024 | |
999 | |
1025 | =over 4 |
1000 | =over 4 |
1026 | |
1001 | |
1027 | =item hash references |
1002 | =item hash references |
1028 | |
1003 | |
1029 | Perl hash references become JSON objects. As there is no inherent ordering |
1004 | Perl hash references become JSON objects. As there is no inherent |
1030 | in hash keys (or JSON objects), they will usually be encoded in a |
1005 | ordering in hash keys (or JSON objects), they will usually be encoded |
1031 | pseudo-random order that can change between runs of the same program but |
1006 | in a pseudo-random order. JSON::XS can optionally sort the hash keys |
1032 | stays generally the same within a single run of a program. JSON::XS can |
1007 | (determined by the I<canonical> flag), so the same datastructure will |
1033 | optionally sort the hash keys (determined by the I<canonical> flag), so |
1008 | serialise to the same JSON text (given same settings and version of |
1034 | the same datastructure will serialise to the same JSON text (given same |
1009 | JSON::XS), but this incurs a runtime overhead and is only rarely useful, |
1035 | settings and version of JSON::XS), but this incurs a runtime overhead |
1010 | e.g. when you want to compare some JSON text against another for equality. |
1036 | and is only rarely useful, e.g. when you want to compare some JSON text |
|
|
1037 | against another for equality. |
|
|
1038 | |
1011 | |
1039 | =item array references |
1012 | =item array references |
1040 | |
1013 | |
1041 | Perl array references become JSON arrays. |
1014 | Perl array references become JSON arrays. |
1042 | |
1015 | |
1043 | =item other references |
1016 | =item other references |
1044 | |
1017 | |
1045 | Other unblessed references are generally not allowed and will cause an |
1018 | Other unblessed references are generally not allowed and will cause an |
1046 | exception to be thrown, except for references to the integers C<0> and |
1019 | exception to be thrown, except for references to the integers C<0> and |
1047 | C<1>, which get turned into C<false> and C<true> atoms in JSON. You can |
1020 | C<1>, which get turned into C<false> and C<true> atoms in JSON. |
1048 | also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability. |
|
|
1049 | |
1021 | |
|
|
1022 | Since C<JSON::XS> uses the boolean model from L<Types::Serialiser>, you |
|
|
1023 | can also C<use Types::Serialiser> and then use C<Types::Serialiser::false> |
|
|
1024 | and C<Types::Serialiser::true> to improve readability. |
|
|
1025 | |
|
|
1026 | use Types::Serialiser; |
1050 | encode_json [\0, JSON::XS::true] # yields [false,true] |
1027 | encode_json [\0, Types::Serialiser::true] # yields [false,true] |
1051 | |
1028 | |
1052 | =item JSON::XS::true, JSON::XS::false |
1029 | =item Types::Serialiser::true, Types::Serialiser::false |
1053 | |
1030 | |
1054 | These special values become JSON true and JSON false values, |
1031 | These special values from the L<Types::Serialiser> module become JSON true |
1055 | respectively. You can also use C<\1> and C<\0> directly if you want. |
1032 | and JSON false values, respectively. You can also use C<\1> and C<\0> |
|
|
1033 | directly if you want. |
1056 | |
1034 | |
1057 | =item blessed objects |
1035 | =item blessed objects |
1058 | |
1036 | |
1059 | Blessed objects are not directly representable in JSON. See the |
1037 | Blessed objects are not directly representable in JSON. See the |
1060 | C<allow_blessed> and C<convert_blessed> methods on various options on |
1038 | C<allow_blessed> and C<convert_blessed> methods on various options on |
… | |
… | |
1138 | =item C<utf8> flag disabled |
1116 | =item C<utf8> flag disabled |
1139 | |
1117 | |
1140 | When C<utf8> is disabled (the default), then C<encode>/C<decode> generate |
1118 | When C<utf8> is disabled (the default), then C<encode>/C<decode> generate |
1141 | and expect Unicode strings, that is, characters with high ordinal Unicode |
1119 | and expect Unicode strings, that is, characters with high ordinal Unicode |
1142 | values (> 255) will be encoded as such characters, and likewise such |
1120 | values (> 255) will be encoded as such characters, and likewise such |
1143 | characters are decoded as-is, no canges to them will be done, except |
1121 | characters are decoded as-is, no changes to them will be done, except |
1144 | "(re-)interpreting" them as Unicode codepoints or Unicode characters, |
1122 | "(re-)interpreting" them as Unicode codepoints or Unicode characters, |
1145 | respectively (to Perl, these are the same thing in strings unless you do |
1123 | respectively (to Perl, these are the same thing in strings unless you do |
1146 | funny/weird/dumb stuff). |
1124 | funny/weird/dumb stuff). |
1147 | |
1125 | |
1148 | This is useful when you want to do the encoding yourself (e.g. when you |
1126 | This is useful when you want to do the encoding yourself (e.g. when you |
… | |
… | |
1264 | output for these property strings, e.g.: |
1242 | output for these property strings, e.g.: |
1265 | |
1243 | |
1266 | $json =~ s/"__proto__"\s*:/"__proto__renamed":/g; |
1244 | $json =~ s/"__proto__"\s*:/"__proto__renamed":/g; |
1267 | |
1245 | |
1268 | This works because C<__proto__> is not valid outside of strings, so every |
1246 | This works because C<__proto__> is not valid outside of strings, so every |
1269 | occurence of C<"__proto__"\s*:> must be a string used as property name. |
1247 | occurrence of C<"__proto__"\s*:> must be a string used as property name. |
1270 | |
1248 | |
1271 | If you know of other incompatibilities, please let me know. |
1249 | If you know of other incompatibilities, please let me know. |
1272 | |
1250 | |
1273 | |
1251 | |
1274 | =head2 JSON and YAML |
1252 | =head2 JSON and YAML |
… | |
… | |
1436 | are browser design bugs, but it is still you who will have to deal with |
1414 | are browser design bugs, but it is still you who will have to deal with |
1437 | it, as major browser developers care only for features, not about getting |
1415 | it, as major browser developers care only for features, not about getting |
1438 | security right). |
1416 | security right). |
1439 | |
1417 | |
1440 | |
1418 | |
|
|
1419 | =head1 INTEROPERABILITY WITH OTHER MODULES |
|
|
1420 | |
|
|
1421 | C<JSON::XS> uses the L<Types::Serialiser> module to provide boolean |
|
|
1422 | constants. That means that the JSON true and false values will be |
|
|
1423 | comaptible to true and false values of iother modules that do the same, |
|
|
1424 | such as L<JSON::PP> and L<CBOR::XS>. |
|
|
1425 | |
|
|
1426 | |
1441 | =head1 THREADS |
1427 | =head1 THREADS |
1442 | |
1428 | |
1443 | This module is I<not> guaranteed to be thread safe and there are no |
1429 | This module is I<not> guaranteed to be thread safe and there are no |
1444 | plans to change this until Perl gets thread support (as opposed to the |
1430 | plans to change this until Perl gets thread support (as opposed to the |
1445 | horribly slow so-called "threads" which are simply slow and bloated |
1431 | horribly slow so-called "threads" which are simply slow and bloated |
… | |
… | |
1452 | |
1438 | |
1453 | Sometimes people avoid the Perl locale support and directly call the |
1439 | Sometimes people avoid the Perl locale support and directly call the |
1454 | system's setlocale function with C<LC_ALL>. |
1440 | system's setlocale function with C<LC_ALL>. |
1455 | |
1441 | |
1456 | This breaks both perl and modules such as JSON::XS, as stringification of |
1442 | This breaks both perl and modules such as JSON::XS, as stringification of |
1457 | numbers no longer works correcly (e.g. C<$x = 0.1; print "$x"+1> might |
1443 | numbers no longer works correctly (e.g. C<$x = 0.1; print "$x"+1> might |
1458 | print C<1>, and JSON::XS might output illegal JSON as JSON::XS relies on |
1444 | print C<1>, and JSON::XS might output illegal JSON as JSON::XS relies on |
1459 | perl to stringify numbers). |
1445 | perl to stringify numbers). |
1460 | |
1446 | |
1461 | The solution is simple: don't call C<setlocale>, or use it for only those |
1447 | The solution is simple: don't call C<setlocale>, or use it for only those |
1462 | categories you need, such as C<LC_MESSAGES> or C<LC_CTYPE>. |
1448 | categories you need, such as C<LC_MESSAGES> or C<LC_CTYPE>. |
… | |
… | |
1475 | Please refrain from using rt.cpan.org or any other bug reporting |
1461 | Please refrain from using rt.cpan.org or any other bug reporting |
1476 | service. I put the contact address into my modules for a reason. |
1462 | service. I put the contact address into my modules for a reason. |
1477 | |
1463 | |
1478 | =cut |
1464 | =cut |
1479 | |
1465 | |
1480 | our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" }; |
1466 | BEGIN { |
1481 | our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" }; |
1467 | *true = \$Types::Serialiser::true; |
|
|
1468 | *true = \&Types::Serialiser::true; |
|
|
1469 | *false = \$Types::Serialiser::false; |
|
|
1470 | *false = \&Types::Serialiser::false; |
|
|
1471 | *is_bool = \&Types::Serialiser::is_bool; |
1482 | |
1472 | |
1483 | sub true() { $true } |
1473 | *JSON::XS::Boolean:: = *Types::Serialiser::Boolean::; |
1484 | sub false() { $false } |
|
|
1485 | |
|
|
1486 | sub is_bool($) { |
|
|
1487 | UNIVERSAL::isa $_[0], "JSON::XS::Boolean" |
|
|
1488 | # or UNIVERSAL::isa $_[0], "JSON::Literal" |
|
|
1489 | } |
1474 | } |
1490 | |
1475 | |
1491 | XSLoader::load "JSON::XS", $VERSION; |
1476 | XSLoader::load "JSON::XS", $VERSION; |
1492 | |
|
|
1493 | package JSON::XS::Boolean; |
|
|
1494 | |
|
|
1495 | use overload |
|
|
1496 | "0+" => sub { ${$_[0]} }, |
|
|
1497 | "++" => sub { $_[0] = ${$_[0]} + 1 }, |
|
|
1498 | "--" => sub { $_[0] = ${$_[0]} - 1 }, |
|
|
1499 | fallback => 1; |
|
|
1500 | |
|
|
1501 | 1; |
|
|
1502 | |
1477 | |
1503 | =head1 SEE ALSO |
1478 | =head1 SEE ALSO |
1504 | |
1479 | |
1505 | The F<json_xs> command line utility for quick experiments. |
1480 | The F<json_xs> command line utility for quick experiments. |
1506 | |
1481 | |
… | |
… | |
1509 | Marc Lehmann <schmorp@schmorp.de> |
1484 | Marc Lehmann <schmorp@schmorp.de> |
1510 | http://home.schmorp.de/ |
1485 | http://home.schmorp.de/ |
1511 | |
1486 | |
1512 | =cut |
1487 | =cut |
1513 | |
1488 | |
|
|
1489 | 1 |
|
|
1490 | |