Note: This is a fork of the abandoned CPAN version by Miko O'Sullivan. I forked it for my own purposes. If it is useful for you, enjoy and participate!
There's been increasing support for the idea of expanding JSON to improve human-readability. "Relaxed" JSON (RJSON) is a term that has been used to describe a JSON-ish format that has some human-friendly features that JSON doesn't. Most notably, RJSON allows the use of JavaScript-like comments and eliminates the need to quote all keys and values. An (official) specification can be found on RelaxedJSON.org.
Note that by definition every JSON document is also a valid RJSON document.
use JSON::Relaxed;
# Some raw RJSON data.
my $rjson = <<'RAW_DATA';
/* Javascript-like comments. */
{
// Keys do not require quotes.
// Single, double and backtick quotes.
a : 'Larry',
b : "Curly",
c : `Phoey`,
// Simple values do not require quotes.
d: unquoted
// Nested structures.
e: [
{ a:1, b:2 },
],
// Like Perl, trailing commas are allowed.
f: "more stuff",
}
RAW_DATA
# Functional parsing.
my $hash = decode_rjson($rjson);
# Object-oriented parsing.
my $parser = JSON::Relaxed->new();
$hash = $parser->decode($rjson);
# Pretty output.
print encode_json( data => $hash, pretty => 1 );
JSON::Relaxed is a lightweight parser and serializer for RJSON. It is fully compliant to the RelaxedJSON.org specification.
Extensions can be disabled with the strict
option.
Hash keys without values
JSON::Relaxed supports object keys without a specified value. In that case the hash element is simply assigned the undefined value.
In the following example, a is assigned 1, and b is assigned undef:
{ a:1, b }
Implied outer hash braces
If the input starts with a hash key, the outer braces are implied. The following are identical
a : 1 b : 2
{ a : 1, b : 2 }
Optional colon for hash-valued keys
If a key is associated with a hash value, the colon may be left out. The following are identical
a { b : 1 }
a : { b : 1 }
Combined hash keys
Multiple levels of keys, separated by periods. The following are identical
a.b.c : 1
a : { b : { c : 1 } }
This even works for arrays, but can be tricky:
a.2.c : 1
a [ null, null, { c : 1 } ]
But
a.2.c : 1 a.1.d : 2
a [ null, { d : 2 }, { c : 1 } ]
String continuation
Long strings can be split over multiple lines by putting a backslash at the end of the line:
"this is a " \ "long string"
Note that this is different from
"this is a \ long string"
which embeds the newline into the string.
Extended Unicode escapes
Unicode escapes in strings may contain an arbitrary number of hexadecimal digits enclosed in braces:
\u{1d10e}
This eliminates the need to use surrogates to obtain the same character:
\uD834\uDD0E
$structure = decode_rjson($data)
decode_rjson()
is the simple way to parse an RJSON string.
It is exported by default.
decode_rjson
takes a single parameter, the string to be parsed.
Optionally an additional hash with options can be passed to change the behaviour of the parser. See Object-oriented parsing in JSON::Relaxed::Parser.
$structure = decode_rjson( $rjson, %options );
encode_json
produces a formatted string from a Perl data structure.
It takes a hash as argument.
$string = encode_json( data => $struct, %options )
Possible options are
strict
If set to a true value, the formatted string will conform to strict Relaxed JSON.
pretty
The result will be pretty-printed, i.e. nicely formatted for human eyes.
schema
If this argument is provided it must be the result from parsing a
valid JSON Schema that is associated with the data to be formatted.
The "description"
nodes from the schema will be used to provide
comments in the output.
To parse using an object, create a JSON::Relaxed
object:
$parser = JSON::Relaxed->new();
Then call the parser's decode
method, passing in the RJSON string:
$structure = $parser->decode($rjson);
Similar for encoding:
$string = $parser->encode( data => $structure );
For more details, see Object-oriented parsing in JSON::Relaxed.
If the document cannot be parsed, JSON::Relaxed returns an undefined value and sets error indicators in $JSON::Relaxed::Parser::err_id and $JSON::Relaxed::Parser::err_msg. For a full list of error codes, see JSON::Relaxed::ErrorCodes.
The old static method from_rjson
has been renamed to decode_rjson
,
to conform to many other modules of this kind.
from_rjson
is kept as a synonym for decode_rjson
.
For the same reason, the old parser method parse
has been renamed to decode
.
parse
is kept as a synonym for decode
.
Johan Vromans jv@cpan.org
Miko O'Sullivan miko@idocs.com
, original version.
Development of this module takes place on GitHub: https://github.com/sciurius/perl-JSON-Relaxed.
You can find documentation for this module with the perldoc command.
perldoc JSON::Relaxed
Please report any bugs or feature requests using the issue tracker on GitHub.
Copyright (c) 2024 by Johan Vromans. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. This software comes with NO WARRANTY of any kind.
Original copyright 2014 by Miko O'Sullivan. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. This software comes with NO WARRANTY of any kind.