NAME

Sereal::Path - XPath or JSONPath for Sereal

SYNOPSIS

use Sereal::Path;
use Sereal::Encoder qw/encode_sereal/;

my $data = [ { foo => 'bar' }, { foo => 'barbar' } ];
my $sp = Sereal::Path->new(encode_sereal($data));

# $result will contain { foo => 'bar' }
my $result = sp->traverse('$[0]');

# $result1 will contain [ 'bar', 'barbar' ]
my $result1 = $sp->traverse('$[*][foo]');

DESCRIPTION

Sereal::Path for Sereal is the same as XPath for XML or JSONPath for JSON. Sereal::Path can directly work with encoded Sereal document. In other words, there is no need to decode a document before executing queries against it.

As of first public release of Sereal::Path, it's considered to be in beta phase and is not ready for production usage.

Sereal::Path derived it query syntax from JSONPath. Its documentation can be found at http://goessner.net/articles/JsonPath/.

However, Sereal::Path supports a subset of JSONPath. Below is the comparasion between XPath, JSONPath and Sereal::Path:

XPath           JSONPath            Sereal::Path            Description
/               $                   $                       The root object/element
.               @                   not impl                The current object/element
/               . or []             . or []                 Child operator
..              n/a                 n/a                     Parent operator
//              ..                  not impl                Recursive descent. JSONPath borrows this syntax from E4X.
*               *                   *                       Wildcard. All objects/elements regardless their names.
@               n/a                 n/a                     Attribute access. JSON structures don't have attributes.
[]              []                  []                      Subscript operator. XPath uses it to iterate over element
                                                            collections and for predicates. In Javascript and JSON it
                                                            is the native array operator.
|               [,]                 [,]                     Union operator in XPath results in a combination of node sets.
                                                            JSONPath allows alternate names or array indices as a set.
n/a             [start:end:step]    [start:end:step]        Array slice operator borrowed from ES4.
[]              ?()                 not impl                Applies a filter (script) expression.
n/a             ()                  not impl                Script expression, using the underlying script engine.
()              n/a                 n/a                     Grouping in Xpath

Items which are marked as 'not impl' will be implemented at later stages of the project.

IMPORTANT

Sereal::Path is still under development. It's possible that API will be change at any moment.

ACKNOWLEDGMENT

This module was inspired by JSON::Path module by Toby Inkster which is a port of the PHP JSONPath implementation (version 0.8.x) by Stefan Goessner. See http://code.google.com/p/jsonpath/.

This module was originally developed for Booking.com. With approval from Booking.com, this module was generalized and published on CPAN, for which the authors would like to express their gratitude.

AUTHOR

Ivan Kruglov <ivan.kruglov@yahoo.com>

COPYRIGHT AND LICENCE

Copyright 2007 Stefan Goessner.

Copyright 2010-2013 Toby Inkster.

Copyright 2014-2015 Ivan Kruglov.

This module is tri-licensed. It is available under the X11 (a.k.a. MIT) licence; you can also redistribute it and/or modify it under the same terms as Perl itself.

a.k.a. "The MIT Licence"

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.