… | |
… | |
64 | so, and even documents what "correct" means. |
64 | so, and even documents what "correct" means. |
65 | |
65 | |
66 | =item * round-trip integrity |
66 | =item * round-trip integrity |
67 | |
67 | |
68 | When you serialise a perl data structure using only data types supported |
68 | When you serialise a perl data structure using only data types supported |
69 | by JSON, the deserialised data structure is identical on the Perl level. |
69 | by JSON and Perl, the deserialised data structure is identical on the Perl |
70 | (e.g. the string "2.0" doesn't suddenly become "2" just because it looks |
70 | level. (e.g. the string "2.0" doesn't suddenly become "2" just because |
71 | like a number). There minor I<are> exceptions to this, read the MAPPING |
71 | it looks like a number). There I<are> minor exceptions to this, read the |
72 | section below to learn about those. |
72 | MAPPING section below to learn about those. |
73 | |
73 | |
74 | =item * strict checking of JSON correctness |
74 | =item * strict checking of JSON correctness |
75 | |
75 | |
76 | There is no guessing, no generating of illegal JSON texts by default, |
76 | There is no guessing, no generating of illegal JSON texts by default, |
77 | and only JSON is accepted as input by default (the latter is a security |
77 | and only JSON is accepted as input by default (the latter is a security |
… | |
… | |
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 |
… | |
… | |
99 | |
99 | |
100 | =cut |
100 | =cut |
101 | |
101 | |
102 | package JSON::XS; |
102 | package JSON::XS; |
103 | |
103 | |
104 | no warnings; |
104 | use common::sense; |
105 | use strict; |
|
|
106 | |
105 | |
107 | our $VERSION = '2.232'; |
106 | our $VERSION = '3.0'; |
108 | our @ISA = qw(Exporter); |
107 | our @ISA = qw(Exporter); |
109 | |
108 | |
110 | our @EXPORT = qw(encode_json decode_json to_json from_json); |
109 | our @EXPORT = qw(encode_json decode_json); |
111 | |
|
|
112 | sub to_json($) { |
|
|
113 | require Carp; |
|
|
114 | 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"); |
|
|
115 | } |
|
|
116 | |
|
|
117 | sub from_json($) { |
|
|
118 | require Carp; |
|
|
119 | 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"); |
|
|
120 | } |
|
|
121 | |
110 | |
122 | use Exporter; |
111 | use Exporter; |
123 | use XSLoader; |
112 | use XSLoader; |
|
|
113 | |
|
|
114 | use Types::Serialiser (); |
124 | |
115 | |
125 | =head1 FUNCTIONAL INTERFACE |
116 | =head1 FUNCTIONAL INTERFACE |
126 | |
117 | |
127 | The following convenience methods are provided by this module. They are |
118 | The following convenience methods are provided by this module. They are |
128 | exported by default: |
119 | exported by default: |
… | |
… | |
149 | This function call is functionally identical to: |
140 | This function call is functionally identical to: |
150 | |
141 | |
151 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
142 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
152 | |
143 | |
153 | Except being faster. |
144 | Except being faster. |
154 | |
|
|
155 | =item $is_boolean = JSON::XS::is_bool $scalar |
|
|
156 | |
|
|
157 | Returns true if the passed scalar represents either JSON::XS::true or |
|
|
158 | JSON::XS::false, two constants that act like C<1> and C<0>, respectively |
|
|
159 | and are used to represent JSON C<true> and C<false> values in Perl. |
|
|
160 | |
|
|
161 | See MAPPING, below, for more information on how JSON values are mapped to |
|
|
162 | Perl. |
|
|
163 | |
145 | |
164 | =back |
146 | =back |
165 | |
147 | |
166 | |
148 | |
167 | =head1 A FEW NOTES ON UNICODE AND PERL |
149 | =head1 A FEW NOTES ON UNICODE AND PERL |
… | |
… | |
433 | If C<$enable> is true (or missing), then the C<encode> method will output JSON objects |
415 | If C<$enable> is true (or missing), then the C<encode> method will output JSON objects |
434 | by sorting their keys. This is adding a comparatively high overhead. |
416 | by sorting their keys. This is adding a comparatively high overhead. |
435 | |
417 | |
436 | If C<$enable> is false, then the C<encode> method will output key-value |
418 | If C<$enable> is false, then the C<encode> method will output key-value |
437 | pairs in the order Perl stores them (which will likely change between runs |
419 | pairs in the order Perl stores them (which will likely change between runs |
438 | of the same script). |
420 | of the same script, and can change even within the same run from 5.18 |
|
|
421 | onwards). |
439 | |
422 | |
440 | This option is useful if you want the same data structure to be encoded as |
423 | This option is useful if you want the same data structure to be encoded as |
441 | the same JSON text (given the same overall settings). If it is disabled, |
424 | the same JSON text (given the same overall settings). If it is disabled, |
442 | the same hash might be encoded differently even if contains the same data, |
425 | the same hash might be encoded differently even if contains the same data, |
443 | as key-value pairs have no inherent ordering in Perl. |
426 | as key-value pairs have no inherent ordering in Perl. |
444 | |
427 | |
445 | This setting has no effect when decoding JSON texts. |
428 | This setting has no effect when decoding JSON texts. |
|
|
429 | |
|
|
430 | This setting has currently no effect on tied hashes. |
446 | |
431 | |
447 | =item $json = $json->allow_nonref ([$enable]) |
432 | =item $json = $json->allow_nonref ([$enable]) |
448 | |
433 | |
449 | =item $enabled = $json->get_allow_nonref |
434 | =item $enabled = $json->get_allow_nonref |
450 | |
435 | |
… | |
… | |
665 | |
650 | |
666 | 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. |
667 | |
652 | |
668 | =item $json_text = $json->encode ($perl_scalar) |
653 | =item $json_text = $json->encode ($perl_scalar) |
669 | |
654 | |
670 | Converts the given Perl data structure (a simple scalar or a reference |
655 | Converts the given Perl value or data structure to its JSON |
671 | to a hash or array) to its JSON representation. Simple scalars will be |
656 | representation. Croaks on error. |
672 | converted into JSON string or number sequences, while references to arrays |
|
|
673 | become JSON arrays and references to hashes become JSON objects. Undefined |
|
|
674 | Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true> |
|
|
675 | nor C<false> values will be generated. |
|
|
676 | |
657 | |
677 | =item $perl_scalar = $json->decode ($json_text) |
658 | =item $perl_scalar = $json->decode ($json_text) |
678 | |
659 | |
679 | 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, |
680 | returning the resulting simple scalar or reference. Croaks on error. |
661 | returning the resulting simple scalar or reference. Croaks on error. |
681 | |
|
|
682 | JSON numbers and strings become simple Perl scalars. JSON arrays become |
|
|
683 | Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes |
|
|
684 | C<1>, C<false> becomes C<0> and C<null> becomes C<undef>. |
|
|
685 | |
662 | |
686 | =item ($perl_scalar, $characters) = $json->decode_prefix ($json_text) |
663 | =item ($perl_scalar, $characters) = $json->decode_prefix ($json_text) |
687 | |
664 | |
688 | 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 |
689 | 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 |
690 | silently stop parsing there and return the number of characters consumed |
667 | silently stop parsing there and return the number of characters consumed |
691 | so far. |
668 | so far. |
692 | |
669 | |
693 | 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 |
694 | (which is not the brightest thing to do in the first place) and you need |
|
|
695 | to know where the JSON text ends. |
671 | and you need to know where the JSON text ends. |
696 | |
672 | |
697 | JSON::XS->new->decode_prefix ("[1] the tail") |
673 | JSON::XS->new->decode_prefix ("[1] the tail") |
698 | => ([], 3) |
674 | => ([], 3) |
699 | |
675 | |
700 | =back |
676 | =back |
… | |
… | |
712 | calls). |
688 | calls). |
713 | |
689 | |
714 | JSON::XS will only attempt to parse the JSON text once it is sure it |
690 | JSON::XS will only attempt to parse the JSON text once it is sure it |
715 | has enough text to get a decisive result, using a very simple but |
691 | has enough text to get a decisive result, using a very simple but |
716 | truly incremental parser. This means that it sometimes won't stop as |
692 | truly incremental parser. This means that it sometimes won't stop as |
717 | early as the full parser, for example, it doesn't detect parenthese |
693 | early as the full parser, for example, it doesn't detect mismatched |
718 | mismatches. The only thing it guarantees is that it starts decoding as |
694 | parentheses. The only thing it guarantees is that it starts decoding as |
719 | soon as a syntactically valid JSON text has been seen. This means you need |
695 | soon as a syntactically valid JSON text has been seen. This means you need |
720 | to set resource limits (e.g. C<max_size>) to ensure the parser will stop |
696 | to set resource limits (e.g. C<max_size>) to ensure the parser will stop |
721 | parsing in the presence if syntax errors. |
697 | parsing in the presence if syntax errors. |
722 | |
698 | |
723 | The following methods implement this incremental parser. |
699 | The following methods implement this incremental parser. |
… | |
… | |
739 | |
715 | |
740 | 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 |
741 | 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 |
742 | 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, |
743 | 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 |
744 | 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 |
745 | using the method. |
721 | using the method. |
746 | |
722 | |
747 | 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 |
748 | 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 |
749 | 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 |
750 | objects or arrays, instead they must be concatenated back-to-back. If |
726 | objects or arrays, instead they must be concatenated back-to-back. If |
751 | an error occurs, an exception will be raised as in the scalar context |
727 | an error occurs, an exception will be raised as in the scalar context |
752 | case. Note that in this case, any previously-parsed JSON texts will be |
728 | case. Note that in this case, any previously-parsed JSON texts will be |
753 | lost. |
729 | lost. |
754 | |
730 | |
|
|
731 | Example: Parse some JSON arrays/objects in a given string and return |
|
|
732 | them. |
|
|
733 | |
|
|
734 | my @objs = JSON::XS->new->incr_parse ("[5][7][1,2]"); |
|
|
735 | |
755 | =item $lvalue_string = $json->incr_text |
736 | =item $lvalue_string = $json->incr_text |
756 | |
737 | |
757 | This method returns the currently stored JSON fragment as an lvalue, that |
738 | This method returns the currently stored JSON fragment as an lvalue, that |
758 | is, you can manipulate it. This I<only> works when a preceding call to |
739 | is, you can manipulate it. This I<only> works when a preceding call to |
759 | C<incr_parse> in I<scalar context> successfully returned an object. Under |
740 | C<incr_parse> in I<scalar context> successfully returned an object. Under |
… | |
… | |
773 | 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 |
774 | 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 |
775 | parse state. |
756 | parse state. |
776 | |
757 | |
777 | 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 |
778 | occured is removed. |
759 | occurred is removed. |
779 | |
760 | |
780 | =item $json->incr_reset |
761 | =item $json->incr_reset |
781 | |
762 | |
782 | This completely resets the incremental parser, that is, after this call, |
763 | This completely resets the incremental parser, that is, after this call, |
783 | it will be as if the parser had never parsed anything. |
764 | it will be as if the parser had never parsed anything. |
… | |
… | |
789 | =back |
770 | =back |
790 | |
771 | |
791 | =head2 LIMITATIONS |
772 | =head2 LIMITATIONS |
792 | |
773 | |
793 | All options that affect decoding are supported, except |
774 | All options that affect decoding are supported, except |
794 | 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 |
795 | 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 |
796 | 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 |
797 | for JSON numbers, however. |
778 | not hold true for JSON numbers, however. |
798 | |
779 | |
799 | 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 |
800 | 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 |
801 | 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 |
802 | takes the conservative route and disallows this case. |
783 | takes the conservative route and disallows this case. |
… | |
… | |
981 | 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 |
982 | 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 |
983 | 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 |
984 | 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 |
985 | 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 |
986 | re-encoded toa JSON string). |
967 | re-encoded to a JSON string). |
987 | |
968 | |
988 | Numbers containing a fractional or exponential part will always be |
969 | Numbers containing a fractional or exponential part will always be |
989 | represented as numeric (floating point) values, possibly at a loss of |
970 | represented as numeric (floating point) values, possibly at a loss of |
990 | precision (in which case you might lose perfect roundtripping ability, but |
971 | precision (in which case you might lose perfect roundtripping ability, but |
991 | 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). |
992 | |
973 | |
|
|
974 | Note that precision is not accuracy - binary floating point values cannot |
|
|
975 | represent most decimal fractions exactly, and when converting from and to |
|
|
976 | floating point, JSON::XS only guarantees precision up to but not including |
|
|
977 | the least significant bit. |
|
|
978 | |
993 | =item true, false |
979 | =item true, false |
994 | |
980 | |
995 | These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>, |
981 | These JSON atoms become C<Types::Serialiser::true> and |
996 | respectively. They are overloaded to act almost exactly like the numbers |
982 | C<Types::Serialiser::false>, respectively. They are overloaded to act |
997 | 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 |
998 | 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). |
999 | |
986 | |
1000 | =item null |
987 | =item null |
1001 | |
988 | |
1002 | A JSON null atom becomes C<undef> in Perl. |
989 | A JSON null atom becomes C<undef> in Perl. |
|
|
990 | |
|
|
991 | =item shell-style comments (C<< # I<text> >>) |
|
|
992 | |
|
|
993 | As a nonstandard extension to the JSON syntax that is enabled by the |
|
|
994 | C<relaxed> setting, shell-style comments are allowed. They can start |
|
|
995 | anywhere outside strings and go till the end of the line. |
|
|
996 | |
|
|
997 | =item tagged values (C<< (I<tag>)I<value> >>). |
|
|
998 | |
|
|
999 | Another nonstandard extension to the JSON syntax, enabled with the |
|
|
1000 | C<allow_tags> setting, are tagged values. In this implementation, the |
|
|
1001 | I<tag> must be a perl package/class name encoded as a JSON string, and the |
|
|
1002 | I<value> must be a JSON array encoding optional constructor arguments. |
|
|
1003 | |
|
|
1004 | See "OBJECT SERIALISATION", below, for details. |
1003 | |
1005 | |
1004 | =back |
1006 | =back |
1005 | |
1007 | |
1006 | |
1008 | |
1007 | =head2 PERL -> JSON |
1009 | =head2 PERL -> JSON |
… | |
… | |
1012 | |
1014 | |
1013 | =over 4 |
1015 | =over 4 |
1014 | |
1016 | |
1015 | =item hash references |
1017 | =item hash references |
1016 | |
1018 | |
1017 | Perl hash references become JSON objects. As there is no inherent ordering |
1019 | Perl hash references become JSON objects. As there is no inherent |
1018 | in hash keys (or JSON objects), they will usually be encoded in a |
1020 | ordering in hash keys (or JSON objects), they will usually be encoded |
1019 | pseudo-random order that can change between runs of the same program but |
1021 | in a pseudo-random order. JSON::XS can optionally sort the hash keys |
1020 | stays generally the same within a single run of a program. JSON::XS can |
1022 | (determined by the I<canonical> flag), so the same datastructure will |
1021 | optionally sort the hash keys (determined by the I<canonical> flag), so |
1023 | serialise to the same JSON text (given same settings and version of |
1022 | the same datastructure will serialise to the same JSON text (given same |
1024 | JSON::XS), but this incurs a runtime overhead and is only rarely useful, |
1023 | settings and version of JSON::XS), but this incurs a runtime overhead |
1025 | e.g. when you want to compare some JSON text against another for equality. |
1024 | and is only rarely useful, e.g. when you want to compare some JSON text |
|
|
1025 | against another for equality. |
|
|
1026 | |
1026 | |
1027 | =item array references |
1027 | =item array references |
1028 | |
1028 | |
1029 | Perl array references become JSON arrays. |
1029 | Perl array references become JSON arrays. |
1030 | |
1030 | |
1031 | =item other references |
1031 | =item other references |
1032 | |
1032 | |
1033 | Other unblessed references are generally not allowed and will cause an |
1033 | Other unblessed references are generally not allowed and will cause an |
1034 | exception to be thrown, except for references to the integers C<0> and |
1034 | exception to be thrown, except for references to the integers C<0> and |
1035 | C<1>, which get turned into C<false> and C<true> atoms in JSON. You can |
1035 | C<1>, which get turned into C<false> and C<true> atoms in JSON. |
1036 | also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability. |
|
|
1037 | |
1036 | |
|
|
1037 | Since C<JSON::XS> uses the boolean model from L<Types::Serialiser>, you |
|
|
1038 | can also C<use Types::Serialiser> and then use C<Types::Serialiser::false> |
|
|
1039 | and C<Types::Serialiser::true> to improve readability. |
|
|
1040 | |
|
|
1041 | use Types::Serialiser; |
1038 | encode_json [\0, JSON::XS::true] # yields [false,true] |
1042 | encode_json [\0, Types::Serialiser::true] # yields [false,true] |
1039 | |
1043 | |
1040 | =item JSON::XS::true, JSON::XS::false |
1044 | =item Types::Serialiser::true, Types::Serialiser::false |
1041 | |
1045 | |
1042 | These special values become JSON true and JSON false values, |
1046 | These special values from the L<Types::Serialiser> module become JSON true |
1043 | respectively. You can also use C<\1> and C<\0> directly if you want. |
1047 | and JSON false values, respectively. You can also use C<\1> and C<\0> |
|
|
1048 | directly if you want. |
1044 | |
1049 | |
1045 | =item blessed objects |
1050 | =item blessed objects |
1046 | |
1051 | |
1047 | Blessed objects are not directly representable in JSON. See the |
1052 | Blessed objects are not directly representable in JSON, but C<JSON::XS> |
1048 | C<allow_blessed> and C<convert_blessed> methods on various options on |
1053 | allows various ways of handling objects. See "OBJECT SERIALISATION", |
1049 | how to deal with this: basically, you can choose between throwing an |
1054 | below, for details. |
1050 | exception, encoding the reference as if it weren't blessed, or provide |
|
|
1051 | your own serialiser method. |
|
|
1052 | |
1055 | |
1053 | =item simple scalars |
1056 | =item simple scalars |
1054 | |
1057 | |
1055 | Simple Perl scalars (any scalar that is not a reference) are the most |
1058 | Simple Perl scalars (any scalar that is not a reference) are the most |
1056 | difficult objects to encode: JSON::XS will encode undefined scalars as |
1059 | difficult objects to encode: JSON::XS will encode undefined scalars as |
… | |
… | |
1084 | |
1087 | |
1085 | You can not currently force the type in other, less obscure, ways. Tell me |
1088 | You can not currently force the type in other, less obscure, ways. Tell me |
1086 | if you need this capability (but don't forget to explain why it's needed |
1089 | if you need this capability (but don't forget to explain why it's needed |
1087 | :). |
1090 | :). |
1088 | |
1091 | |
|
|
1092 | Note that numerical precision has the same meaning as under Perl (so |
|
|
1093 | binary to decimal conversion follows the same rules as in Perl, which |
|
|
1094 | can differ to other languages). Also, your perl interpreter might expose |
|
|
1095 | extensions to the floating point numbers of your platform, such as |
|
|
1096 | infinities or NaN's - these cannot be represented in JSON, and it is an |
|
|
1097 | error to pass those in. |
|
|
1098 | |
1089 | =back |
1099 | =back |
|
|
1100 | |
|
|
1101 | =head2 OBJECT SERIALISATION |
|
|
1102 | |
|
|
1103 | As JSON cannot directly represent Perl objects, you have to choose between |
|
|
1104 | a pure JSON representation (without the ability to deserialise the object |
|
|
1105 | automatically again), and a nonstandard extension to the JSON syntax, |
|
|
1106 | tagged values. |
|
|
1107 | |
|
|
1108 | =head3 SERIALISATION |
|
|
1109 | |
|
|
1110 | What happens when C<JSON::XS> encounters a Perl object depends on the |
|
|
1111 | C<allow_blessed>, C<convert_blessed> and C<allow_tags> settings, which are |
|
|
1112 | used in this order: |
|
|
1113 | |
|
|
1114 | =over 4 |
|
|
1115 | |
|
|
1116 | =item 1. C<allow_tags> is enabled and object has a C<FREEZE> method. |
|
|
1117 | |
|
|
1118 | In this case, C<JSON::XS> uses the L<Types::Serialiser> object |
|
|
1119 | serialisation protocol to create a tagged JSON value, using a nonstandard |
|
|
1120 | extension to the JSON syntax. |
|
|
1121 | |
|
|
1122 | This works by invoking the C<FREEZE> method on the object, with the first |
|
|
1123 | argument being the object to serialise, and the second argument being the |
|
|
1124 | constant string C<JSON> to distinguish it from other serialisers. |
|
|
1125 | |
|
|
1126 | The C<FREEZE> method can return any number of values (i.e. zero or |
|
|
1127 | more). These values and the paclkage/classname of the object will then be |
|
|
1128 | encoded as a tagged JSON value in the following format: |
|
|
1129 | |
|
|
1130 | ("classname")[FREEZE return values...] |
|
|
1131 | |
|
|
1132 | For example, the hypothetical C<My::Object> C<FREEZE> method might use the |
|
|
1133 | objects C<type> and C<id> members to encode the object: |
|
|
1134 | |
|
|
1135 | sub My::Object::FREEZE { |
|
|
1136 | my ($self, $serialiser) = @_; |
|
|
1137 | |
|
|
1138 | ($self->{type}, $self->{id}) |
|
|
1139 | } |
|
|
1140 | |
|
|
1141 | =item 2. C<convert_blessed> is enabled and object has a C<TO_JSON> method. |
|
|
1142 | |
|
|
1143 | In this case, the C<TO_JSON> method of the object is invoked in scalar |
|
|
1144 | context. It must return a single scalar that can be directly encoded into |
|
|
1145 | JSON. This scalar replaces the object in the JSON text. |
|
|
1146 | |
|
|
1147 | For example, the following C<TO_JSON> method will convert all L<URI> |
|
|
1148 | objects to JSON strings when serialised. The fatc that these values |
|
|
1149 | originally were L<URI> objects is lost. |
|
|
1150 | |
|
|
1151 | sub URI::TO_JSON { |
|
|
1152 | my ($uri) = @_; |
|
|
1153 | $uri->as_string |
|
|
1154 | } |
|
|
1155 | |
|
|
1156 | =item 3. C<allow_blessed> is enabled. |
|
|
1157 | |
|
|
1158 | The object will be serialised as a JSON null value. |
|
|
1159 | |
|
|
1160 | =item 4. none of the above |
|
|
1161 | |
|
|
1162 | If none of the settings are enabled or the respective methods are missing, |
|
|
1163 | C<JSON::XS> throws an exception. |
|
|
1164 | |
|
|
1165 | =back |
|
|
1166 | |
|
|
1167 | =head3 DESERIALISATION |
|
|
1168 | |
|
|
1169 | For deserialisation there are only two cases to consider: either |
|
|
1170 | nonstandard tagging was used, in which case C<allow_tags> decides, |
|
|
1171 | or objects cannot be automatically be deserialised, in which |
|
|
1172 | case you can use postprocessing or the C<filter_json_object> or |
|
|
1173 | C<filter_json_single_key_object> callbacks to get some real objects our of |
|
|
1174 | your JSON. |
|
|
1175 | |
|
|
1176 | This section only considers the tagged value case: I a tagged JSON object |
|
|
1177 | is encountered during decoding and C<allow_tags> is disabled, a parse |
|
|
1178 | error will result (as if tagged values were not part of the grammar). |
|
|
1179 | |
|
|
1180 | If C<allow_tags> is enabled, C<JSON::XS> will look up the C<THAW> method |
|
|
1181 | of the package/classname used during serialisation. If there is no such |
|
|
1182 | method, the decoding will fail with an error. |
|
|
1183 | |
|
|
1184 | Otherwise, the C<THAW> method is invoked with the classname as first |
|
|
1185 | argument, the constant string C<JSON> as second argument, and all the |
|
|
1186 | values from the JSON array (the values originally returned by the |
|
|
1187 | C<FREEZE> method) as remaining arguments. |
|
|
1188 | |
|
|
1189 | The method must then return the object. While technically you can return |
|
|
1190 | any Perl scalar, you might have to enable the C<enable_nonref> setting to |
|
|
1191 | make that work in all cases, so better return an actual blessed reference. |
|
|
1192 | |
|
|
1193 | As an example, let's implement a C<THAW> function that regenerates the |
|
|
1194 | C<My::Object> from the C<FREEZE> example earlier: |
|
|
1195 | |
|
|
1196 | sub My::Object::THAW { |
|
|
1197 | my ($class, $serialiser, $type, $id) = @_; |
|
|
1198 | |
|
|
1199 | $class->new (type => $type, id => $id) |
|
|
1200 | } |
1090 | |
1201 | |
1091 | |
1202 | |
1092 | =head1 ENCODING/CODESET FLAG NOTES |
1203 | =head1 ENCODING/CODESET FLAG NOTES |
1093 | |
1204 | |
1094 | The interested reader might have seen a number of flags that signify |
1205 | The interested reader might have seen a number of flags that signify |
… | |
… | |
1119 | =item C<utf8> flag disabled |
1230 | =item C<utf8> flag disabled |
1120 | |
1231 | |
1121 | When C<utf8> is disabled (the default), then C<encode>/C<decode> generate |
1232 | When C<utf8> is disabled (the default), then C<encode>/C<decode> generate |
1122 | and expect Unicode strings, that is, characters with high ordinal Unicode |
1233 | and expect Unicode strings, that is, characters with high ordinal Unicode |
1123 | values (> 255) will be encoded as such characters, and likewise such |
1234 | values (> 255) will be encoded as such characters, and likewise such |
1124 | characters are decoded as-is, no canges to them will be done, except |
1235 | characters are decoded as-is, no changes to them will be done, except |
1125 | "(re-)interpreting" them as Unicode codepoints or Unicode characters, |
1236 | "(re-)interpreting" them as Unicode codepoints or Unicode characters, |
1126 | respectively (to Perl, these are the same thing in strings unless you do |
1237 | respectively (to Perl, these are the same thing in strings unless you do |
1127 | funny/weird/dumb stuff). |
1238 | funny/weird/dumb stuff). |
1128 | |
1239 | |
1129 | This is useful when you want to do the encoding yourself (e.g. when you |
1240 | This is useful when you want to do the encoding yourself (e.g. when you |
… | |
… | |
1209 | use JSON::XS; |
1320 | use JSON::XS; |
1210 | |
1321 | |
1211 | print encode_json [chr 0x2028]; |
1322 | print encode_json [chr 0x2028]; |
1212 | |
1323 | |
1213 | The right fix for this is to use a proper JSON parser in your javascript |
1324 | The right fix for this is to use a proper JSON parser in your javascript |
1214 | programs, and not rely on C<eval>. |
1325 | programs, and not rely on C<eval> (see for example Douglas Crockford's |
|
|
1326 | F<json2.js> parser). |
1215 | |
1327 | |
1216 | If this is not an option, you can, as a stop-gap measure, simply encode to |
1328 | If this is not an option, you can, as a stop-gap measure, simply encode to |
1217 | ASCII-only JSON: |
1329 | ASCII-only JSON: |
1218 | |
1330 | |
1219 | use JSON::XS; |
1331 | use JSON::XS; |
1220 | |
1332 | |
1221 | print JSON::XS->new->ascii->encode ([chr 0x2028]); |
1333 | print JSON::XS->new->ascii->encode ([chr 0x2028]); |
1222 | |
1334 | |
1223 | And if you are concerned about the size of the resulting JSON text, you |
1335 | Note that this will enlarge the resulting JSON text quite a bit if you |
1224 | can run some regexes to only escape U+2028 and U+2029: |
1336 | have many non-ASCII characters. You might be tempted to run some regexes |
|
|
1337 | to only escape U+2028 and U+2029, e.g.: |
1225 | |
1338 | |
1226 | use JSON::XS; |
1339 | # DO NOT USE THIS! |
1227 | |
|
|
1228 | my $json = JSON::XS->new->utf8->encode ([chr 0x2028]); |
1340 | my $json = JSON::XS->new->utf8->encode ([chr 0x2028]); |
1229 | $json =~ s/\xe2\x80\xa8/\\u2028/g; # escape U+2028 |
1341 | $json =~ s/\xe2\x80\xa8/\\u2028/g; # escape U+2028 |
1230 | $json =~ s/\xe2\x80\xa9/\\u2029/g; # escape U+2029 |
1342 | $json =~ s/\xe2\x80\xa9/\\u2029/g; # escape U+2029 |
1231 | print $json; |
1343 | print $json; |
1232 | |
1344 | |
1233 | This works because U+2028/U+2029 are not allowed outside of strings and |
1345 | Note that I<this is a bad idea>: the above only works for U+2028 and |
1234 | are not used for syntax, so replacing them unconditionally just works. |
|
|
1235 | |
|
|
1236 | Note, however, that fixing the broken JSON parser is better than working |
|
|
1237 | around it in every other generator. The above regexes should work well in |
|
|
1238 | other languages, as long as they operate on UTF-8. It is equally valid to |
|
|
1239 | replace all occurences of U+2028/2029 directly by their \\u-escaped forms |
|
|
1240 | in unicode texts, so they can simply be used to fix any parsers relying on |
|
|
1241 | C<eval> by first applying the regexes on the encoded texts. |
|
|
1242 | |
|
|
1243 | Note also that the above only works for U+2028 and U+2029 and thus |
|
|
1244 | only for fully ECMAscript-compliant parsers. Many existing javascript |
1346 | U+2029 and thus only for fully ECMAscript-compliant parsers. Many existing |
1245 | implementations misparse other characters as well. Best rely on a good |
1347 | javascript implementations, however, have issues with other characters as |
1246 | JSON parser, such as Douglas Crockfords F<json2.js>, which escapes the |
1348 | well - using C<eval> naively simply I<will> cause problems. |
1247 | above and many more problematic characters properly before passing them |
|
|
1248 | into C<eval>. |
|
|
1249 | |
1349 | |
1250 | Another problem is that some javascript implementations reserve |
1350 | Another problem is that some javascript implementations reserve |
1251 | some property names for their own purposes (which probably makes |
1351 | some property names for their own purposes (which probably makes |
1252 | them non-ECMAscript-compliant). For example, Iceweasel reserves the |
1352 | them non-ECMAscript-compliant). For example, Iceweasel reserves the |
1253 | C<__proto__> property name for it's own purposes. |
1353 | C<__proto__> property name for its own purposes. |
1254 | |
1354 | |
1255 | If that is a problem, you could parse try to filter the resulting JSON |
1355 | If that is a problem, you could parse try to filter the resulting JSON |
1256 | output for these property strings, e.g.: |
1356 | output for these property strings, e.g.: |
1257 | |
1357 | |
1258 | $json =~ s/"__proto__"\s*:/"__proto__renamed":/g; |
1358 | $json =~ s/"__proto__"\s*:/"__proto__renamed":/g; |
1259 | |
1359 | |
1260 | This works because C<__proto__> is not valid outside of strings, so every |
1360 | This works because C<__proto__> is not valid outside of strings, so every |
1261 | occurence of C<"__proto__"\s*:> must be a string used as property name. |
1361 | occurrence of C<"__proto__"\s*:> must be a string used as property name. |
1262 | |
1362 | |
1263 | If you know of other incompatibilities, please let me know. |
1363 | If you know of other incompatibilities, please let me know. |
1264 | |
1364 | |
1265 | |
1365 | |
1266 | =head2 JSON and YAML |
1366 | =head2 JSON and YAML |
… | |
… | |
1278 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
1378 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
1279 | |
1379 | |
1280 | This will I<usually> generate JSON texts that also parse as valid |
1380 | This will I<usually> generate JSON texts that also parse as valid |
1281 | YAML. Please note that YAML has hardcoded limits on (simple) object key |
1381 | YAML. Please note that YAML has hardcoded limits on (simple) object key |
1282 | lengths that JSON doesn't have and also has different and incompatible |
1382 | lengths that JSON doesn't have and also has different and incompatible |
1283 | unicode handling, so you should make sure that your hash keys are |
1383 | unicode character escape syntax, so you should make sure that your hash |
1284 | noticeably shorter than the 1024 "stream characters" YAML allows and that |
1384 | keys are noticeably shorter than the 1024 "stream characters" YAML allows |
1285 | you do not have characters with codepoint values outside the Unicode BMP |
1385 | and that you do not have characters with codepoint values outside the |
1286 | (basic multilingual page). YAML also does not allow C<\/> sequences in |
1386 | Unicode BMP (basic multilingual page). YAML also does not allow C<\/> |
1287 | strings (which JSON::XS does not I<currently> generate, but other JSON |
1387 | sequences in strings (which JSON::XS does not I<currently> generate, but |
1288 | generators might). |
1388 | other JSON generators might). |
1289 | |
1389 | |
1290 | There might be other incompatibilities that I am not aware of (or the YAML |
1390 | There might be other incompatibilities that I am not aware of (or the YAML |
1291 | specification has been changed yet again - it does so quite often). In |
1391 | specification has been changed yet again - it does so quite often). In |
1292 | general you should not try to generate YAML with a JSON generator or vice |
1392 | general you should not try to generate YAML with a JSON generator or vice |
1293 | versa, or try to parse JSON with a YAML parser or vice versa: chances are |
1393 | versa, or try to parse JSON with a YAML parser or vice versa: chances are |
… | |
… | |
1312 | that difficult or long) and finally make YAML compatible to it, and |
1412 | that difficult or long) and finally make YAML compatible to it, and |
1313 | educating users about the changes, instead of spreading lies about the |
1413 | educating users about the changes, instead of spreading lies about the |
1314 | real compatibility for many I<years> and trying to silence people who |
1414 | real compatibility for many I<years> and trying to silence people who |
1315 | point out that it isn't true. |
1415 | point out that it isn't true. |
1316 | |
1416 | |
|
|
1417 | Addendum/2009: the YAML 1.2 spec is still incompatible with JSON, even |
|
|
1418 | though the incompatibilities have been documented (and are known to Brian) |
|
|
1419 | for many years and the spec makes explicit claims that YAML is a superset |
|
|
1420 | of JSON. It would be so easy to fix, but apparently, bullying people and |
|
|
1421 | corrupting userdata is so much easier. |
|
|
1422 | |
1317 | =back |
1423 | =back |
1318 | |
1424 | |
1319 | |
1425 | |
1320 | =head2 SPEED |
1426 | =head2 SPEED |
1321 | |
1427 | |
… | |
… | |
1328 | a very short single-line JSON string (also available at |
1434 | a very short single-line JSON string (also available at |
1329 | L<http://dist.schmorp.de/misc/json/short.json>). |
1435 | L<http://dist.schmorp.de/misc/json/short.json>). |
1330 | |
1436 | |
1331 | {"method": "handleMessage", "params": ["user1", |
1437 | {"method": "handleMessage", "params": ["user1", |
1332 | "we were just talking"], "id": null, "array":[1,11,234,-5,1e5,1e7, |
1438 | "we were just talking"], "id": null, "array":[1,11,234,-5,1e5,1e7, |
1333 | true, false]} |
1439 | 1, 0]} |
1334 | |
1440 | |
1335 | It shows the number of encodes/decodes per second (JSON::XS uses |
1441 | It shows the number of encodes/decodes per second (JSON::XS uses |
1336 | the functional interface, while JSON::XS/2 uses the OO interface |
1442 | the functional interface, while JSON::XS/2 uses the OO interface |
1337 | with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables |
1443 | with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables |
1338 | shrink). Higher is better: |
1444 | shrink. JSON::DWIW/DS uses the deserialise function, while JSON::DWIW::FJ |
|
|
1445 | uses the from_json method). Higher is better: |
1339 | |
1446 | |
1340 | module | encode | decode | |
1447 | module | encode | decode | |
1341 | -----------|------------|------------| |
1448 | --------------|------------|------------| |
1342 | JSON 1.x | 4990.842 | 4088.813 | |
1449 | JSON::DWIW/DS | 86302.551 | 102300.098 | |
1343 | JSON::DWIW | 51653.990 | 71575.154 | |
1450 | JSON::DWIW/FJ | 86302.551 | 75983.768 | |
1344 | JSON::PC | 65948.176 | 74631.744 | |
1451 | JSON::PP | 15827.562 | 6638.658 | |
1345 | JSON::PP | 8931.652 | 3817.168 | |
1452 | JSON::Syck | 63358.066 | 47662.545 | |
1346 | JSON::Syck | 24877.248 | 27776.848 | |
1453 | JSON::XS | 511500.488 | 511500.488 | |
1347 | JSON::XS | 388361.481 | 227951.304 | |
1454 | JSON::XS/2 | 291271.111 | 388361.481 | |
1348 | JSON::XS/2 | 227951.304 | 218453.333 | |
1455 | JSON::XS/3 | 361577.931 | 361577.931 | |
1349 | JSON::XS/3 | 338250.323 | 218453.333 | |
1456 | Storable | 66788.280 | 265462.278 | |
1350 | Storable | 16500.016 | 135300.129 | |
|
|
1351 | -----------+------------+------------+ |
1457 | --------------+------------+------------+ |
1352 | |
1458 | |
1353 | That is, JSON::XS is about five times faster than JSON::DWIW on encoding, |
1459 | That is, JSON::XS is almost six times faster than JSON::DWIW on encoding, |
1354 | about three times faster on decoding, and over forty times faster |
1460 | about five times faster on decoding, and over thirty to seventy times |
1355 | than JSON, even with pretty-printing and key sorting. It also compares |
1461 | faster than JSON's pure perl implementation. It also compares favourably |
1356 | favourably to Storable for small amounts of data. |
1462 | to Storable for small amounts of data. |
1357 | |
1463 | |
1358 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
1464 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
1359 | search API (L<http://dist.schmorp.de/misc/json/long.json>). |
1465 | search API (L<http://dist.schmorp.de/misc/json/long.json>). |
1360 | |
1466 | |
1361 | module | encode | decode | |
1467 | module | encode | decode | |
1362 | -----------|------------|------------| |
1468 | --------------|------------|------------| |
1363 | JSON 1.x | 55.260 | 34.971 | |
1469 | JSON::DWIW/DS | 1647.927 | 2673.916 | |
1364 | JSON::DWIW | 825.228 | 1082.513 | |
1470 | JSON::DWIW/FJ | 1630.249 | 2596.128 | |
1365 | JSON::PC | 3571.444 | 2394.829 | |
|
|
1366 | JSON::PP | 210.987 | 32.574 | |
1471 | JSON::PP | 400.640 | 62.311 | |
1367 | JSON::Syck | 552.551 | 787.544 | |
1472 | JSON::Syck | 1481.040 | 1524.869 | |
1368 | JSON::XS | 5780.463 | 4854.519 | |
1473 | JSON::XS | 20661.596 | 9541.183 | |
1369 | JSON::XS/2 | 3869.998 | 4798.975 | |
1474 | JSON::XS/2 | 10683.403 | 9416.938 | |
1370 | JSON::XS/3 | 5862.880 | 4798.975 | |
1475 | JSON::XS/3 | 20661.596 | 9400.054 | |
1371 | Storable | 4445.002 | 5235.027 | |
1476 | Storable | 19765.806 | 10000.725 | |
1372 | -----------+------------+------------+ |
1477 | --------------+------------+------------+ |
1373 | |
1478 | |
1374 | Again, JSON::XS leads by far (except for Storable which non-surprisingly |
1479 | Again, JSON::XS leads by far (except for Storable which non-surprisingly |
1375 | decodes faster). |
1480 | decodes a bit faster). |
1376 | |
1481 | |
1377 | On large strings containing lots of high Unicode characters, some modules |
1482 | On large strings containing lots of high Unicode characters, some modules |
1378 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
1483 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
1379 | will be broken due to missing (or wrong) Unicode handling. Others refuse |
1484 | will be broken due to missing (or wrong) Unicode handling. Others refuse |
1380 | to decode or encode properly, so it was impossible to prepare a fair |
1485 | to decode or encode properly, so it was impossible to prepare a fair |
… | |
… | |
1416 | information you might want to make sure that exceptions thrown by JSON::XS |
1521 | information you might want to make sure that exceptions thrown by JSON::XS |
1417 | will not end up in front of untrusted eyes. |
1522 | will not end up in front of untrusted eyes. |
1418 | |
1523 | |
1419 | If you are using JSON::XS to return packets to consumption |
1524 | If you are using JSON::XS to return packets to consumption |
1420 | by JavaScript scripts in a browser you should have a look at |
1525 | by JavaScript scripts in a browser you should have a look at |
1421 | L<http://jpsykes.com/47/practical-csrf-and-json-security> to see whether |
1526 | L<http://blog.archive.jpsykes.com/47/practical-csrf-and-json-security/> to |
1422 | you are vulnerable to some common attack vectors (which really are browser |
1527 | see whether you are vulnerable to some common attack vectors (which really |
1423 | design bugs, but it is still you who will have to deal with it, as major |
1528 | are browser design bugs, but it is still you who will have to deal with |
1424 | browser developers care only for features, not about getting security |
1529 | it, as major browser developers care only for features, not about getting |
1425 | right). |
1530 | security right). |
|
|
1531 | |
|
|
1532 | |
|
|
1533 | =head1 INTEROPERABILITY WITH OTHER MODULES |
|
|
1534 | |
|
|
1535 | C<JSON::XS> uses the L<Types::Serialiser> module to provide boolean |
|
|
1536 | constants. That means that the JSON true and false values will be |
|
|
1537 | comaptible to true and false values of iother modules that do the same, |
|
|
1538 | such as L<JSON::PP> and L<CBOR::XS>. |
1426 | |
1539 | |
1427 | |
1540 | |
1428 | =head1 THREADS |
1541 | =head1 THREADS |
1429 | |
1542 | |
1430 | This module is I<not> guaranteed to be thread safe and there are no |
1543 | This module is I<not> guaranteed to be thread safe and there are no |
… | |
… | |
1433 | process simulations - use fork, it's I<much> faster, cheaper, better). |
1546 | process simulations - use fork, it's I<much> faster, cheaper, better). |
1434 | |
1547 | |
1435 | (It might actually work, but you have been warned). |
1548 | (It might actually work, but you have been warned). |
1436 | |
1549 | |
1437 | |
1550 | |
|
|
1551 | =head1 THE PERILS OF SETLOCALE |
|
|
1552 | |
|
|
1553 | Sometimes people avoid the Perl locale support and directly call the |
|
|
1554 | system's setlocale function with C<LC_ALL>. |
|
|
1555 | |
|
|
1556 | This breaks both perl and modules such as JSON::XS, as stringification of |
|
|
1557 | numbers no longer works correctly (e.g. C<$x = 0.1; print "$x"+1> might |
|
|
1558 | print C<1>, and JSON::XS might output illegal JSON as JSON::XS relies on |
|
|
1559 | perl to stringify numbers). |
|
|
1560 | |
|
|
1561 | The solution is simple: don't call C<setlocale>, or use it for only those |
|
|
1562 | categories you need, such as C<LC_MESSAGES> or C<LC_CTYPE>. |
|
|
1563 | |
|
|
1564 | If you need C<LC_NUMERIC>, you should enable it only around the code that |
|
|
1565 | actually needs it (avoiding stringification of numbers), and restore it |
|
|
1566 | afterwards. |
|
|
1567 | |
|
|
1568 | |
1438 | =head1 BUGS |
1569 | =head1 BUGS |
1439 | |
1570 | |
1440 | While the goal of this module is to be correct, that unfortunately does |
1571 | While the goal of this module is to be correct, that unfortunately does |
1441 | not mean it's bug-free, only that I think its design is bug-free. If you |
1572 | not mean it's bug-free, only that I think its design is bug-free. If you |
1442 | keep reporting bugs they will be fixed swiftly, though. |
1573 | keep reporting bugs they will be fixed swiftly, though. |
… | |
… | |
1444 | Please refrain from using rt.cpan.org or any other bug reporting |
1575 | Please refrain from using rt.cpan.org or any other bug reporting |
1445 | service. I put the contact address into my modules for a reason. |
1576 | service. I put the contact address into my modules for a reason. |
1446 | |
1577 | |
1447 | =cut |
1578 | =cut |
1448 | |
1579 | |
1449 | our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" }; |
1580 | BEGIN { |
1450 | our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" }; |
1581 | *true = \$Types::Serialiser::true; |
|
|
1582 | *true = \&Types::Serialiser::true; |
|
|
1583 | *false = \$Types::Serialiser::false; |
|
|
1584 | *false = \&Types::Serialiser::false; |
|
|
1585 | *is_bool = \&Types::Serialiser::is_bool; |
1451 | |
1586 | |
1452 | sub true() { $true } |
1587 | *JSON::XS::Boolean:: = *Types::Serialiser::Boolean::; |
1453 | sub false() { $false } |
|
|
1454 | |
|
|
1455 | sub is_bool($) { |
|
|
1456 | UNIVERSAL::isa $_[0], "JSON::XS::Boolean" |
|
|
1457 | # or UNIVERSAL::isa $_[0], "JSON::Literal" |
|
|
1458 | } |
1588 | } |
1459 | |
1589 | |
1460 | XSLoader::load "JSON::XS", $VERSION; |
1590 | XSLoader::load "JSON::XS", $VERSION; |
1461 | |
|
|
1462 | package JSON::XS::Boolean; |
|
|
1463 | |
|
|
1464 | use overload |
|
|
1465 | "0+" => sub { ${$_[0]} }, |
|
|
1466 | "++" => sub { $_[0] = ${$_[0]} + 1 }, |
|
|
1467 | "--" => sub { $_[0] = ${$_[0]} - 1 }, |
|
|
1468 | fallback => 1; |
|
|
1469 | |
|
|
1470 | 1; |
|
|
1471 | |
1591 | |
1472 | =head1 SEE ALSO |
1592 | =head1 SEE ALSO |
1473 | |
1593 | |
1474 | The F<json_xs> command line utility for quick experiments. |
1594 | The F<json_xs> command line utility for quick experiments. |
1475 | |
1595 | |
… | |
… | |
1478 | Marc Lehmann <schmorp@schmorp.de> |
1598 | Marc Lehmann <schmorp@schmorp.de> |
1479 | http://home.schmorp.de/ |
1599 | http://home.schmorp.de/ |
1480 | |
1600 | |
1481 | =cut |
1601 | =cut |
1482 | |
1602 | |
|
|
1603 | 1 |
|
|
1604 | |