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85 | |
85 | |
86 | package JSON::XS; |
86 | package JSON::XS; |
87 | |
87 | |
88 | use strict; |
88 | use strict; |
89 | |
89 | |
90 | BEGIN { |
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91 | our $VERSION = '1.12'; |
90 | our $VERSION = '1.3'; |
92 | our @ISA = qw(Exporter); |
91 | our @ISA = qw(Exporter); |
93 | |
92 | |
94 | our @EXPORT = qw(to_json from_json objToJson jsonToObj); |
93 | our @EXPORT = qw(to_json from_json objToJson jsonToObj); |
95 | require Exporter; |
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96 | |
94 | |
97 | require XSLoader; |
95 | use Exporter; |
98 | XSLoader::load JSON::XS::, $VERSION; |
96 | use XSLoader; |
99 | } |
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100 | |
97 | |
101 | =head1 FUNCTIONAL INTERFACE |
98 | =head1 FUNCTIONAL INTERFACE |
102 | |
99 | |
103 | The following convinience methods are provided by this module. They are |
100 | The following convinience methods are provided by this module. They are |
104 | exported by default: |
101 | exported by default: |
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126 | This function call is functionally identical to: |
123 | This function call is functionally identical to: |
127 | |
124 | |
128 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
125 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
129 | |
126 | |
130 | except being faster. |
127 | except being faster. |
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128 | |
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129 | =item $is_boolean = JSON::XS::is_bool $scalar |
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130 | |
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131 | Returns true if the passed scalar represents either JSON::XS::true or |
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132 | JSON::XS::false, two constants that act like C<1> and C<0>, respectively |
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133 | and are used to represent JSON C<true> and C<false> values in Perl. |
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134 | |
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135 | See MAPPING, below, for more information on how JSON values are mapped to |
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136 | Perl. |
131 | |
137 | |
132 | =back |
138 | =back |
133 | |
139 | |
134 | |
140 | |
135 | =head1 OBJECT-ORIENTED INTERFACE |
141 | =head1 OBJECT-ORIENTED INTERFACE |
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374 | |
380 | |
375 | JSON numbers and strings become simple Perl scalars. JSON arrays become |
381 | JSON numbers and strings become simple Perl scalars. JSON arrays become |
376 | Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes |
382 | Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes |
377 | C<1>, C<false> becomes C<0> and C<null> becomes C<undef>. |
383 | C<1>, C<false> becomes C<0> and C<null> becomes C<undef>. |
378 | |
384 | |
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385 | =item ($perl_scalar, $characters) = $json->decode_prefix ($json_text) |
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386 | |
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387 | This works like the C<decode> method, but instead of raising an exception |
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388 | when there is trailing garbage after the first JSON object, it will |
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389 | silently stop parsing there and return the number of characters consumed |
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390 | so far. |
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391 | |
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392 | This is useful if your JSON texts are not delimited by an outer protocol |
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393 | (which is not the brightest thing to do in the first place) and you need |
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394 | to know where the JSON text ends. |
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395 | |
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396 | JSON::XS->new->decode_prefix ("[1] the tail") |
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397 | => ([], 3) |
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398 | |
379 | =back |
399 | =back |
380 | |
400 | |
381 | |
401 | |
382 | =head1 MAPPING |
402 | =head1 MAPPING |
383 | |
403 | |
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387 | (what you put in comes out as something equivalent). |
407 | (what you put in comes out as something equivalent). |
388 | |
408 | |
389 | For the more enlightened: note that in the following descriptions, |
409 | For the more enlightened: note that in the following descriptions, |
390 | lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl> |
410 | lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl> |
391 | refers to the abstract Perl language itself. |
411 | refers to the abstract Perl language itself. |
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412 | |
392 | |
413 | |
393 | =head2 JSON -> PERL |
414 | =head2 JSON -> PERL |
394 | |
415 | |
395 | =over 4 |
416 | =over 4 |
396 | |
417 | |
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417 | conversion details, but an integer may take slightly less memory and might |
438 | conversion details, but an integer may take slightly less memory and might |
418 | represent more values exactly than (floating point) numbers. |
439 | represent more values exactly than (floating point) numbers. |
419 | |
440 | |
420 | =item true, false |
441 | =item true, false |
421 | |
442 | |
422 | These JSON atoms become C<0>, C<1>, respectively. Information is lost in |
443 | These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>, |
423 | this process. Future versions might represent those values differently, |
444 | respectively. They are overloaded to act almost exactly like the numbers |
424 | but they will be guarenteed to act like these integers would normally in |
445 | C<1> and C<0>. You can check wether a scalar is a JSON boolean by using |
425 | Perl. |
446 | the C<JSON::XS::is_bool> function. |
426 | |
447 | |
427 | =item null |
448 | =item null |
428 | |
449 | |
429 | A JSON null atom becomes C<undef> in Perl. |
450 | A JSON null atom becomes C<undef> in Perl. |
430 | |
451 | |
431 | =back |
452 | =back |
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453 | |
432 | |
454 | |
433 | =head2 PERL -> JSON |
455 | =head2 PERL -> JSON |
434 | |
456 | |
435 | The mapping from Perl to JSON is slightly more difficult, as Perl is a |
457 | The mapping from Perl to JSON is slightly more difficult, as Perl is a |
436 | truly typeless language, so we can only guess which JSON type is meant by |
458 | truly typeless language, so we can only guess which JSON type is meant by |
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461 | C<1>, which get turned into C<false> and C<true> atoms in JSON. You can |
483 | C<1>, which get turned into C<false> and C<true> atoms in JSON. You can |
462 | also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability. |
484 | also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability. |
463 | |
485 | |
464 | to_json [\0,JSON::XS::true] # yields [false,true] |
486 | to_json [\0,JSON::XS::true] # yields [false,true] |
465 | |
487 | |
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488 | =item JSON::XS::true, JSON::XS::false |
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489 | |
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490 | These special values become JSON true and JSON false values, |
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491 | respectively. You cna alos use C<\1> and C<\0> directly if you want. |
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492 | |
466 | =item blessed objects |
493 | =item blessed objects |
467 | |
494 | |
468 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
495 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
469 | underlying representation (hash- or arrayref), but this behaviour might |
496 | underlying representation (hash- or arrayref), but this behaviour might |
470 | change in future versions. |
497 | change in future versions. |
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591 | |
618 | |
592 | Does not check input for validity. |
619 | Does not check input for validity. |
593 | |
620 | |
594 | =back |
621 | =back |
595 | |
622 | |
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623 | |
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624 | =head2 JSON and YAML |
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625 | |
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626 | You often hear that JSON is a subset (or a close subset) of YAML. This is, |
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627 | however, a mass hysteria and very far from the truth. In general, there is |
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628 | no way to configure JSON::XS to output a data structure as valid YAML. |
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629 | |
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630 | If you really must use JSON::XS to generate YAML, you should use this |
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631 | algorithm (subject to change in future versions): |
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632 | |
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633 | my $to_yaml = JSON::XS->new->utf8->space_after (1); |
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634 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
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635 | |
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636 | This will usually generate JSON texts that also parse as valid |
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637 | YAML. Please note that YAML has hardcoded limits on (simple) object key |
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638 | lengths that JSON doesn't have, so you should make sure that your hash |
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639 | keys are noticably shorter than the 1024 characters YAML allows. |
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640 | |
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641 | There might be other incompatibilities that I am not aware of. In general |
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642 | you should not try to generate YAML with a JSON generator or vice versa, |
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643 | or try to parse JSON with a YAML parser or vice versa: chances are high |
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644 | that you will run into severe interoperability problems. |
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645 | |
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646 | |
596 | =head2 SPEED |
647 | =head2 SPEED |
597 | |
648 | |
598 | It seems that JSON::XS is surprisingly fast, as shown in the following |
649 | It seems that JSON::XS is surprisingly fast, as shown in the following |
599 | tables. They have been generated with the help of the C<eg/bench> program |
650 | tables. They have been generated with the help of the C<eg/bench> program |
600 | in the JSON::XS distribution, to make it easy to compare on your own |
651 | in the JSON::XS distribution, to make it easy to compare on your own |
601 | system. |
652 | system. |
602 | |
653 | |
603 | First comes a comparison between various modules using a very short JSON |
654 | First comes a comparison between various modules using a very short |
604 | string: |
655 | single-line JSON string: |
605 | |
656 | |
606 | {"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null} |
657 | {"method": "handleMessage", "params": ["user1", "we were just talking"], \ |
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658 | "id": null, "array":[1,11,234,-5,1e5,1e7, true, false]} |
607 | |
659 | |
608 | It shows the number of encodes/decodes per second (JSON::XS uses the |
660 | It shows the number of encodes/decodes per second (JSON::XS uses |
609 | functional interface, while JSON::XS/2 uses the OO interface with |
661 | the functional interface, while JSON::XS/2 uses the OO interface |
610 | pretty-printing and hashkey sorting enabled). Higher is better: |
662 | with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables |
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663 | shrink). Higher is better: |
611 | |
664 | |
612 | module | encode | decode | |
665 | module | encode | decode | |
613 | -----------|------------|------------| |
666 | -----------|------------|------------| |
614 | JSON | 11488.516 | 7823.035 | |
667 | JSON | 7645.468 | 4208.613 | |
615 | JSON::DWIW | 94708.054 | 129094.260 | |
668 | JSON::DWIW | 40721.398 | 77101.176 | |
616 | JSON::PC | 63884.157 | 128528.212 | |
669 | JSON::PC | 65948.176 | 78251.940 | |
617 | JSON::Syck | 34898.677 | 42096.911 | |
670 | JSON::Syck | 22844.793 | 26479.192 | |
618 | JSON::XS | 654027.064 | 396423.669 | |
671 | JSON::XS | 388361.481 | 199728.762 | |
619 | JSON::XS/2 | 371564.190 | 371725.613 | |
672 | JSON::XS/2 | 218453.333 | 192399.266 | |
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673 | JSON::XS/3 | 338250.323 | 192399.266 | |
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674 | Storable | 15779.925 | 14169.946 | |
620 | -----------+------------+------------+ |
675 | -----------+------------+------------+ |
621 | |
676 | |
622 | That is, JSON::XS is more than six times faster than JSON::DWIW on |
677 | That is, JSON::XS is about five times faster than JSON::DWIW on encoding, |
623 | encoding, more than three times faster on decoding, and about thirty times |
678 | about three times faster on decoding, and over fourty times faster |
624 | faster than JSON, even with pretty-printing and key sorting. |
679 | than JSON, even with pretty-printing and key sorting. It also compares |
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680 | favourably to Storable for small amounts of data. |
625 | |
681 | |
626 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
682 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
627 | search API (http://nanoref.com/yahooapis/mgPdGg): |
683 | search API (http://nanoref.com/yahooapis/mgPdGg): |
628 | |
684 | |
629 | module | encode | decode | |
685 | module | encode | decode | |
630 | -----------|------------|------------| |
686 | -----------|------------|------------| |
631 | JSON | 273.023 | 44.674 | |
687 | JSON | 254.685 | 37.665 | |
632 | JSON::DWIW | 1089.383 | 1145.704 | |
688 | JSON::DWIW | 843.343 | 1049.731 | |
633 | JSON::PC | 3097.419 | 2393.921 | |
689 | JSON::PC | 3602.116 | 2307.352 | |
634 | JSON::Syck | 514.060 | 843.053 | |
690 | JSON::Syck | 505.107 | 787.899 | |
635 | JSON::XS | 6479.668 | 3636.364 | |
691 | JSON::XS | 5747.196 | 3690.220 | |
636 | JSON::XS/2 | 3774.221 | 3599.124 | |
692 | JSON::XS/2 | 3968.121 | 3676.634 | |
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693 | JSON::XS/3 | 6105.246 | 3662.508 | |
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694 | Storable | 4417.337 | 5285.161 | |
637 | -----------+------------+------------+ |
695 | -----------+------------+------------+ |
638 | |
696 | |
639 | Again, JSON::XS leads by far. |
697 | Again, JSON::XS leads by far (except for Storable which non-surprisingly |
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698 | decodes faster). |
640 | |
699 | |
641 | On large strings containing lots of high unicode characters, some modules |
700 | On large strings containing lots of high unicode characters, some modules |
642 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
701 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
643 | will be broken due to missing (or wrong) unicode handling. Others refuse |
702 | will be broken due to missing (or wrong) unicode handling. Others refuse |
644 | to decode or encode properly, so it was impossible to prepare a fair |
703 | to decode or encode properly, so it was impossible to prepare a fair |
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672 | |
731 | |
673 | And last but least, something else could bomb you that I forgot to think |
732 | And last but least, something else could bomb you that I forgot to think |
674 | of. In that case, you get to keep the pieces. I am always open for hints, |
733 | of. In that case, you get to keep the pieces. I am always open for hints, |
675 | though... |
734 | though... |
676 | |
735 | |
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736 | If you are using JSON::XS to return packets to consumption |
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737 | by javascript scripts in a browser you should have a look at |
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738 | L<http://jpsykes.com/47/practical-csrf-and-json-security> to see wether |
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739 | you are vulnerable to some common attack vectors (which really are browser |
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740 | design bugs, but it is still you who will have to deal with it, as major |
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741 | browser developers care only for features, not about doing security |
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742 | right). |
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743 | |
677 | |
744 | |
678 | =head1 BUGS |
745 | =head1 BUGS |
679 | |
746 | |
680 | While the goal of this module is to be correct, that unfortunately does |
747 | While the goal of this module is to be correct, that unfortunately does |
681 | not mean its bug-free, only that I think its design is bug-free. It is |
748 | not mean its bug-free, only that I think its design is bug-free. It is |
682 | still relatively early in its development. If you keep reporting bugs they |
749 | still relatively early in its development. If you keep reporting bugs they |
683 | will be fixed swiftly, though. |
750 | will be fixed swiftly, though. |
684 | |
751 | |
685 | =cut |
752 | =cut |
686 | |
753 | |
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754 | our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" }; |
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755 | our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" }; |
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756 | |
687 | sub true() { \1 } |
757 | sub true() { $true } |
688 | sub false() { \0 } |
758 | sub false() { $false } |
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759 | |
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760 | sub is_bool($) { |
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761 | UNIVERSAL::isa $_[0], "JSON::XS::Boolean" |
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762 | or UNIVERSAL::isa $_[0], "JSON::Literal" |
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763 | } |
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764 | |
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765 | XSLoader::load "JSON::XS", $VERSION; |
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766 | |
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767 | package JSON::XS::Boolean; |
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768 | |
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769 | use overload |
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770 | "0+" => sub { ${$_[0]} }, |
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771 | "++" => sub { $_[0] = ${$_[0]} + 1 }, |
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772 | "--" => sub { $_[0] = ${$_[0]} - 1 }, |
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773 | fallback => 1; |
689 | |
774 | |
690 | 1; |
775 | 1; |
691 | |
776 | |
692 | =head1 AUTHOR |
777 | =head1 AUTHOR |
693 | |
778 | |