NAME

       CPAN::Meta::Merge - Merging CPAN Meta fragments

VERSION

       version 2.150010

SYNOPSIS

        my $merger = CPAN::Meta::Merge->new(default_version => "2");
        my $meta = $merger->merge($base, @additional);

DESCRIPTION

METHODS

   new
       This creates a CPAN::Meta::Merge object. It takes one mandatory named argument, "version",
       declaring the version of the meta-spec that must be used for the merge. It can optionally
       take an "extra_mappings" argument that allows one to add additional merging functions for
       specific elements.

       The "extra_mappings" arguments takes a hash ref with the same type of structure as
       described in CPAN::Meta::Spec, except with its values as one of the defined merge
       strategies or a code ref to a merging function.

         my $merger = CPAN::Meta::Merge->new(
             default_version => '2',
             extra_mappings => {
                 'optional_features' => \&custom_merge_function,
                 'x_custom' => 'set_addition',
                 'x_meta_meta' => {
                     name => 'identical',
                     tags => 'set_addition',
                 }
             }
         );

   merge(@fragments)
       Merge all @fragments together. It will accept both CPAN::Meta objects and (possibly
       incomplete) hashrefs of metadata.

MERGE STRATEGIES

       "merge" uses various strategies to combine different elements of the CPAN::Meta objects.
       The following strategies can be used with the extra_mappings argument of "new":

       identical
           The elements must be identical

       set_addition
           The union of two array refs

             [ a, b ] U [ a, c]  = [ a, b, c ]

       uniq_map
           Key value pairs from the right hash are merged to the left hash.  Key collisions are
           only allowed if their values are the same.  This merge function will recurse into
           nested hash refs following the same merge rules.

       improvise
           This merge strategy will try to pick the appropriate predefined strategy based on what
           element type.  Array refs will try to use the "set_addition" strategy,  Hash refs will
           try to use the "uniq_map" strategy, and everything else will try the "identical"
           strategy.

AUTHORS

       •   David Golden <dagolden@cpan.org>

       •   Ricardo Signes <rjbs@cpan.org>

       •   Adam Kennedy <adamk@cpan.org>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2010 by David Golden, Ricardo Signes, Adam Kennedy and
       Contributors.

       This is free software; you can redistribute it and/or modify it under the same terms as
       the Perl 5 programming language system itself.