plucky (3) Hash::Merge::Simple.3pm.gz

NAME

       Hash::Merge::Simple - Recursively merge two or more hashes, simply

SYNOPSIS

           use Hash::Merge::Simple qw/ merge /;

           my $a = { a => 1 };
           my $b = { a => 100, b => 2};

           # Merge with righthand hash taking precedence
           my $c = merge $a, $b;
           # $c is { a => 100, b => 2 } ... Note: a => 100 has overridden => 1

           # Also, merge will take care to recursively merge any subordinate hashes found
           my $a = { a => 1, c => 3, d => { i => 2 }, r => {} };
           my $b = { b => 2, a => 100, d => { l => 4 } };
           my $c = merge $a, $b;
           # $c is { a => 100, b => 2, c => 3, d => { i => 2, l => 4 }, r => {} }

           # You can also merge more than two hashes at the same time
           # The precedence increases from left to right (the rightmost has the most precedence)
           my $everything = merge $this, $that, $mine, $yours, $kitchen_sink, ...;

DESCRIPTION

       Hash::Merge::Simple will recursively merge two or more hashes and return the result as a new hash
       reference. The merge function will descend and merge hashes that exist under the same node in both the
       left and right hash, but doesn't attempt to combine arrays, objects, scalars, or anything else. The
       rightmost hash also takes precedence, replacing whatever was in the left hash if a conflict occurs.

       This code was pretty much taken straight from Catalyst::Utils, and modified to handle more than 2 hashes
       at the same time.

USAGE

   Hash::Merge::Simple->merge( <hash1>, <hash2>, <hash3>, ..., <hashN> )
   Hash::Merge::Simple::merge( <hash1>, <hash2>, <hash3>, ..., <hashN> )
       Merge <hash1> through <hashN>, with the nth-most (rightmost) hash taking precedence.

       Returns a new hash reference representing the merge.

       NOTE: The code does not currently check for cycles, so infinite loops are possible:

           my $a = {};
           $a->{b} = $a;
           merge $a, $a;

       NOTE: If you want to avoid giving/receiving side effects with the merged result, use "clone_merge" or
       "dclone_merge" An example of this problem (thanks Uri):

           my $left = { a => { b => 2 } } ;
           my $right = { c => 4 } ;

           my $result = merge( $left, $right ) ;

           $left->{a}{b} = 3 ;
           $left->{a}{d} = 5 ;

           # $result->{a}{b} == 3 !
           # $result->{a}{d} == 5 !

   Hash::Merge::Simple->clone_merge( <hash1>, <hash2>, <hash3>, ..., <hashN> )
   Hash::Merge::Simple::clone_merge( <hash1>, <hash2>, <hash3>, ..., <hashN> )
       Perform a merge, clone the merge, and return the result

       This is useful in cases where you need to ensure that the result can be tweaked without fear of
       giving/receiving any side effects

       This method will use Clone to do the cloning

   Hash::Merge::Simple->dclone_merge( <hash1>, <hash2>, <hash3>, ..., <hashN> )
   Hash::Merge::Simple::dclone_merge( <hash1>, <hash2>, <hash3>, ..., <hashN> )
       Perform a merge, clone the merge, and return the result

       This is useful in cases where you need to ensure that the result can be tweaked without fear of
       giving/receiving any side effects

       This method will use Storable ("dclone") to do the cloning

SEE ALSO

       Hash::Merge

       Catalyst::Utils

       Clone

       Storable

ACKNOWLEDGEMENTS

       This code was pretty much taken directly from Catalyst::Utils:

       Sebastian Riedel "sri@cpan.org"

       Yuval Kogman "nothingmuch@woobling.org"

BUGS

       Please report any bugs or feature requests on the bugtracker website
       <https://rt.cpan.org/Public/Dist/Display.html?Name=Hash-Merge-Simple> or by email to
       bug-Hash-Merge-Simple@rt.cpan.org <mailto:bug-Hash-Merge-Simple@rt.cpan.org>.

       When submitting a bug or request, please include a test-file or a patch to an existing test-file that
       illustrates the bug or desired feature.

AUTHOR

       Robert Krimen <robertkrimen@gmail.com>

CONTRIBUTOR

       Graham Knop <haarg@haarg.org>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2008 by Robert Krimen.

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