NAME

Deep::Hash::Utils - functions for iterating over and working with nested hashes

SYNOPSIS

        use Deep::Hash::Utils qw(reach slurp nest deepvalue);

        my %hash = (
                  A => {
                           B => {
                                    W => 1,
                                    X => 2,
                                   },
                           C => {
                                    Y => 3,
                                    Z => 4,
                                   },
                          }
                 );

        while (my @list = reach(\%hash)) {
                print "@list";
        }

        for my $a (sort {$a->[2] cmp $b->[2]} slurp(\%hash)) {
                print "@$a";
        }

        my %new_hash = ();

        nest(\%new_hash,1,2,3,4,5);

        my $value = deepvalue(\%new_hash,1,2,3,4);

DESCRIPTION

This module provides functions for accessing and modifying values in deeply nested data structures.

reach

reach HASHREF

Iterate over each nested data structure contained in the given hash. Returns an array of each nested key/value set.

Just as each lets you iterate over the keys and values in a single hash, reach provides an iterator over any recursively nested data structures.

This helps avoid the need to use layers of nested loops in order to iterate over all entities in nested hashes and arrays.

The reference passed to reach can contain any combination of nested hashes and arrays. Hash keys and values will be ordered in the same manner as when using each, keys, or values.

        use Deep::Hash::Utils qw(reach slurp nest);
        $\ = "\n";

        my %hash = (
                A => {
                        B => {
                                W => 1,
                                X => 2,
                                },
                        C => {
                                Y => 3,
                                Z => 4,
                                },
                        }
                );

        while (my @list = reach(\%hash)) {
                print "@list";
        }

        __END__

        Outputs: 

        A C Z 4
        A C Y 3
        A B W 1
        A B X 2

slurp

slurp HASHREF

Returns a list of arrays generated by reach at once. Use this if you want the same result of reach with the ability to sort each layer of keys.

        for my $a (sort {$a->[2] cmp $b->[2]} slurp(\%hash)) {
                print "@$a";
        }

        __END__

        Output: 

        A B W 1
        A B X 2
        A C Y 3
        A C Z 4

nest

nest HASHREF, LIST

define nested hash keys with a given list

        use Data::Dumper;

        my %new_hash = ();
        nest(\%new_hash,1,2,3,4,5);

        print Dumper \%new_hash;

        __END__

        Output: 

        $VAR1 = {
                  '1' => {
                           '2' => {
                                    '3' => {
                                             '4' => 5
                                           }
                                  }
                         }
                };

deepvalue

deepvalue HASHREF, LIST

retrieve deeply nested values with a list of keys:

        my %new_hash = (
                  '1' => {
                           '2' => {
                                    '3' => {
                                             '4' => 5
                                           }
                                  }
                         }
                );

        print Dumper deepvalue(\%new_hash,1,2,3,4);

        print Dumper deepvalue(\%new_hash,1,2);

        __END__

        Output: 

        $VAR1 = 5;

        $VAR1 = {
                  '3' => {
                           '4' => 5
                         }
                };

EXPORT

None by default.

REPOSITORY

https://github.com/neilbowers/perl-deep-hash-utils

AUTHOR

Chris Becker, <clbecker@gmail.com<gt>

Now maintained by Neil Bowers <neilb@cpan.org>

COPYRIGHT AND LICENSE

Copyright (C) 2009 by Chris Becker

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.5 or, at your option, any later version of Perl 5 you may have available.

cpanm Deep::Hash::Utils

perl -MCPAN -e shell
install Deep::Hash::Utils