249 lines
6.6 KiB
Plaintext
249 lines
6.6 KiB
Plaintext
=pod
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=encoding utf8
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=head1 NAME
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JSON::Tiny - Minimalistic JSON. No dependencies.
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=head1 SYNOPSIS
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use JSON::Tiny qw(decode_json encode_json);
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my $bytes = encode_json {foo => [1, 2], bar => 'hello!', baz => \1};
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my $hash = decode_json $bytes;
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=head1 DESCRIPTION
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L<JSON::Tiny> is a minimalistic standalone adaptation of L<Mojo::JSON>, from
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the L<Mojolicious> framework. It is a single-source-file module with under 300
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lines of code and core-only dependencies.
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Features include transparent Unicode support, speed, small memory footprint,
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and a minimal code base ideal for bundling or inlining. Along with
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L<Mojo::JSON>, it is among the fastest pure-Perl implementations of
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L<RFC 7159|http://tools.ietf.org/html/rfc7159>.
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L<JSON::Tiny> supports normal Perl data types like scalar, array reference,
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hash reference, and will try to call the L<TO_JSON> method on blessed
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references, or stringify them if it doesn't exist.
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Differentiating between strings and numbers in Perl is hard; depending on how
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it has been used, a scalar can be both at the same time. The string value has a
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higher precedence unless both representations are equivalent.
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[1, -2, 3] -> [1, -2, 3]
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{"foo": "bar"} -> {foo => 'bar'}
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Literal names will be translated to and from L<JSON::Tiny> constants or a
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similar native Perl value.
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true -> JSON::Tiny->true
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false -> JSON::Tiny->false
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null -> undef
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Scalar references will be used to generate Booleans, based on if their values
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are true or false.
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\1 => true
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\0 => false
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The two Unicode whitespace characters C<u2028> and C<u2029> will always be
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escaped to make JSONP easier, and the character C</> to prevent XSS attacks.
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=head1 FUNCTIONS
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L<JSON::Tiny> implements the following functions, which can be imported
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individually.
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=head2 decode_json
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my $value = decode_json $bytes;
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Decode JSON to Perl value and die if decoding fails.
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=head2 encode_json
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my $bytes = encode_json {foo => 'bar'};
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Encode Perl value to JSON.
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=head2 false
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my $false = false;
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False value, used because Perl has no equivalent.
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=head2 from_json
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my $value = from_json $chars;
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Decode JSON text that is not C<UTF-8> encoded to Perl value and die if
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decoding fails.
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=head2 j
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my $bytes = j [1, 2, 3];
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my $bytes = j {foo => 'bar'};
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my $value = j $bytes;
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Encode Perl data structure (which may only be an array reference or hash
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reference) or decode JSON. An C<undef> return value indicates a bare C<null>.
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Dies if decoding fails.
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=head2 to_json
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my $chars = to_json {i => '♥ Perl'};
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Encode Perl value to JSON text without C<UTF-8> encoding it.
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=head2 true
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my $true = true;
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True value, used because Perl has no native equivalent.
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=head3 More on Booleans
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A reference to a scalar (even if blessed) is encoded as a Boolean value unless
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it has a TO_JSON method.
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my $json = $j->encode( { b => \1, a => \0 } ); # {"b":true,"a":false}
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Boolean false and true values returned when JSON is decoded are
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JSON::Tiny::_Bool objects with overloaded stringification.
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B<Advanced option>: Users requiring a plain old literal C<0> or C<1>, may set
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C<$JSON::Tiny::FALSE = 0;> and C<$JSON::Tiny::TRUE = 1;>. Any value, including
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blessed references will work. This must be set prior to calling a JSON decoding
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function. Use C<local> to limit scope.
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=head1 Tiny
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JSON::Tiny compared with JSON::PP from the L<JSON> distribution:
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=over 4
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=item * L<JSON::PP> is configurable, but more complex. L<JSON::Tiny> offers
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sane defaults, and no configuration.
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=item * Download and install with C<cpanm>: L<JSON::PP>, 5.2 seconds.
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L<JSON::Tiny>, 1.9 seconds.
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=item * Minimal Dependencies: Both L<JSON::PP> and L<JSON::Tiny> only use core
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dependencies. JSON::Tiny requires Perl 5.8.4, while L<JSON::PP> requires 5.6.
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=item * Simple Design: L<JSON> has 2254 lines of code, six modules and five
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files. Distribution: 85KB.
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L<JSON::Tiny> has under 300 lines of code; an embeddable single-file module.
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Distribution: 18KB.
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=item * L<JSON::PP> has 42 functions and methods. L<JSON::Tiny> has seven.
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=item * Performance:
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Rate JSON_PP JSON_Tiny
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JSON_PP 304/s -- -52%
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JSON_Tiny 636/s 109% --
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L<JSON> uses L<JSON::XS> if it's available, in which case L<JSON> wins.
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See C<examples/json_bench.pl> for benchmark code.
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JSON::Tiny's lightweight design reduces its startup time compared to the
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L<JSON> module. This may benefit frequently run applications like CGI.
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=item * Light Memory Needs: Memory usage was tested with
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L<http://valgrind.org/valgrind> and L<Devel::MemoryTrace::Light> by running
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C<examples/json_pp.pl> and C<examples/json_tiny.pl>.
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valgrind Devel::MemoryTrace::Light
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JSON::PP 5.1MB 3.7MB
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JSON::Tiny 4.5MB 2.6MB
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=back
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=head1 CONFIGURATION AND ENVIRONMENT
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No configuration.
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=head1 DEPENDENCIES
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Perl 5.8.4 or newer. B<Perl 5.10+ is recommended due to bugs in Perl 5.8's
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regular expression engine.>
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=head1 INCOMPATIBILITIES
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Incompatible with L<Exporter> versions older than 5.59 (ie, predating Perl
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5.8.4).
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=head1 AUTHOR
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David Oswald, C<< <davido at cpan.org> >>
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Code and tests adapted from L<Mojo::JSON>.
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=head1 SUPPORT
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Direct support requests to the author. Direct bug reports to CPAN's Request
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Tracker (RT).
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You can find documentation for this module with the perldoc command.
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perldoc JSON::Tiny
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You may look for additional information at:
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=over 4
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=item * Github: Development is hosted on Github at:
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L<http://www.github.com/daoswald/JSON-Tiny>
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=item * RT: CPAN's request tracker (bug reports)
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L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=JSON-Tiny>
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=item * AnnoCPAN: Annotated CPAN documentation
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L<http://annocpan.org/dist/JSON-Tiny>
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=item * CPAN Ratings
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L<http://cpanratings.perl.org/d/JSON-Tiny>
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=item * Search CPAN
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L<http://search.cpan.org/dist/JSON-Tiny/>
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=back
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=head1 ACKNOWLEDGEMENTS
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L<Mojolicious> team for its lightweight JSON implementation. This module was
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adapted from L<Mojo::JSON> because it is robust, minimal, and well tested.
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Mojo::JSON's tests were also adapted to a dependency-free design.
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Christian Hansen, whos L<GitHub Gist|https://gist.github.com/chansen/810296>
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formed the basis for L<Mojo::JSON>, and subsequently JSON::Tiny.
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Randal Schwartz showed his pure-regexp JSON parser
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(L<PerlMonks|http://perlmonks.org/?node_id=995856>) to Los Angeles Perl Mongers
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(09/2012). He wasn't involved in JSON::Tiny, but exploring alternatives to his
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solution led to this project.
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=head1 LICENSE AND COPYRIGHT
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Copyright 2012-2014 David Oswald.
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This program is free software, you can redistribute it and/or modify it under
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the terms of the Artistic License version 2.0.
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See L<http://www.perlfoundation.org/artistic_license_2_0> for more information.
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=head1 SEE ALSO
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L<Mojo::JSON>, L<JSON>, L<RFC7159|http://tools.ietf.org/html/rfc7159>.
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=cut
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