NAME    MQUL - General purpose, MongoDB-style query and update languageSYNOPSIS            use MQUL qw/doc_matches update_doc/;            my $doc = {                    title => 'Freaks and Geeks',                    genres => [qw/comedy drama/],                    imdb_score => 9.4,                    seasons => 1,                    starring => ['Linda Cardellini', 'James Franco', 'Jason Segel'],                    likes => { up => 45, down => 11 }            };            if (doc_matches($doc, {                    title => qr/geeks/i,                    genres => 'comedy',                    imdb_score => { '$gte' => 5, '$lte' => 9.5 },                    starring => { '$type' => 'array', '$size' => 3 },                    'likes.up' => { '$gt' => 40 }            })) {                    # will be true in this example            }            update_doc($doc, {                    '$set' => { title => 'Greeks and Feaks' },                    '$pop' => { genres => 1 },                    '$inc' => { imdb_score => 0.6 },                    '$unset' => { seasons => 1 },                    '$push' => { starring => 'John Francis Daley' },            });            # $doc will now be:            {                    title => 'Greeks and Feaks',                    genres => ['comedy'],                    imdb_score => 10,                    starring => ['Linda Cardellini', 'James Franco', 'Jason Segel', 'John Francis Daley'],                    likes => { up => 45, down => 11 }            }DESCRIPTION    MQUL (for MongoDB-style Query & Update Language; pronounced *"umm,    cool"*; yeah, I know, that's the dumbest thing ever), is a general    purpose implementation of MongoDB's query and update language. The    implementation is not 100% compatible, but it only slightly deviates    from MongoDB's behavior, actually extending it a bit.    The module exports two subroutines: "doc_matches()" and "update_doc()".    The first subroutine takes a document, which is really just a hash-ref    (of whatever complexity), and a query hash-ref built in the MQUL query    language. It returns a true value if the document matches the query, and    a false value otherwise. The second subroutine takes a document and an    update hash-ref built in the MQUL update language. The subroutine    modifies the document (in-place) according to the update hash-ref.    You can use this module for whatever purpose you see fit. It was    actually written for Giddy, my Git-database, and was extracted from its    original code. Outside of the database world, I plan to use it in an    application that performs tests (such as process monitoring for    example), and uses the query language to determine whether the results    are valid or not (in our monitoring example, that could be CPU usage    above a certain threshold and stuff like that). It is also used by    MorboDB, an in-memory clone of MongoDB.  UPGRADE NOTES    My distributions follow the semantic versioning scheme    <http://semver.org/>, so whenever the major version changes, that means    that API changes incompatible with previous versions have been made.    Always read the Changes file before upgrading.  THE LANGUAGE    The language itself is described in MQUL::Reference. This document only    describes the interface of this module.    The reference document also details MQUL's current differences from the    original MongoDB language.INTERFACE  doc_matches( \%document, [ \%query, \@defs ] )    Receives a document hash-ref and possibly a query hash-ref, and returns    true if the document matches the query, false otherwise. If no query is    given (or an empty hash-ref is given), true will be returned (every    document will match an empty query - in accordance with MongoDB).    See "QUERY STRUCTURE" in MQUL::Reference to learn about the structure of    query hash-refs.    Optionally, an even-numbered array reference of dynamically calculated    attribute definitions can be provided. For example:            [ min_val => { '$min' => ['attr1', 'attr2', 'attr3' ] },              max_val => { '$max' => ['attr1', 'attr2', 'attr3' ] },              difference => { '$diff' => ['max_val', 'min_val'] } ]    This defines three dynamic attributes: "min_val", "max_val" and    "difference", which is made up of the first two.    See "DYNAMICALLY CALCULATED ATTRIBUTES" in MQUL::Reference for more    information about dynamic attributes.  update_doc( \%document, \%update )    Receives a document hash-ref and an update hash-ref, and updates the    document in-place according to the update hash-ref. Also returns the    document after the update. If the update hash-ref doesn't have any of    the update modifiers described by the language, then the update hash-ref    is considered as what the document should now be, and so will simply    replace the document hash-ref (once again, in accordance with MongoDB).    See "UPDATE STRUCTURE" in MQUL::Reference to learn about the structure    of update hash-refs.DIAGNOSTICS    "MQUL::doc_matches() requires a document hash-ref."        This error means that you've either haven't passed the        "doc_matches()" subroutine any parameters, or given it a        non-hash-ref document.    "MQUL::doc_matches() expects a query hash-ref."        This error means that you've passed the "doc_matches()" attribute a        non-hash-ref query variable. While you don't actually have to pass a        query variable, if you do, it has to be a hash-ref.    "MQUL::update_doc() requires a document hash-ref."        This error means that you've either haven't passed the        "update_doc()" subroutine any parameters, or given it a non-hash-ref        document.    "MQUL::update_doc() requires an update hash-ref."        This error means that you've passed the "update_doc()" subroutine a        non-hash-ref update variable.    "The %s attribute is not an array in the doc."        This error means that your update hash-ref tries to modify an array        attribute (with $push, $pushAll, $addToSet, $pull, $pullAll, $pop,        $shift and $splice), but the attribute in the document provided to        the "update_doc()" subroutine is not an array.CONFIGURATION AND ENVIRONMENT    MQUL requires no configuration files or environment variables.DEPENDENCIES    MQUL depends on the following modules:    *   Data::Compare    *   Data::Types    *   DateTime::Format::W3CDTF    *   Scalar::Util    *   Try::TinyINCOMPATIBILITIES    None reported.BUGS AND LIMITATIONS    No bugs have been reported.    Please report any bugs or feature requests to "bug-MQUL@rt.cpan.org", or    through the web interface at    <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=MQUL>.AUTHOR    Ido Perlmuter <ido at ido50 dot net>LICENSE AND COPYRIGHT    Copyright (c) 2011-2015, Ido Perlmuter "ido at ido50 dot net".    This module is free software; you can redistribute it and/or modify it    under the same terms as Perl itself, either version 5.8.1 or any later    version. See perlartistic and perlgpl.    The full text of the license can be found in the LICENSE file included    with this module.DISCLAIMER OF WARRANTY    BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY    FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN    OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES    PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER    EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE    ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH    YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL    NECESSARY SERVICING, REPAIR, OR CORRECTION.    IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING    WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR    REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE    TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR    CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE    SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING    RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A    FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF    SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH    DAMAGES.