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YAML::Node(3)         User Contributed Perl Documentation        YAML::Node(3)
NAME
       YAML::Node - A generic data node that encapsulates YAML information
SYNOPSIS
           use YAML;
           use YAML::Node;
           my $ynode = YAML::Node->new({}, 'ingerson.com/fruit');
           %$ynode = qw(orange orange apple red grape green);
           print Dump $ynode;
       yields:
           --- !ingerson.com/fruit
           orange: orange
           apple: red
           grape: green
DESCRIPTION
       A generic node in YAML is similar to a plain hash, array, or scalar
       node in Perl except that it must also keep track of its type. The type
       is a URI called the YAML type tag.
       YAML::Node is a class for generating and manipulating these containers.
       A YAML node (or ynode) is a tied hash, array or scalar. In most ways it
       behaves just like the plain thing. But you can assign and retrieve and
       YAML type tag URI to it. For the hash flavor, you can also assign the
       order that the keys will be retrieved in. By default a ynode will offer
       its keys in the same order that they were assigned.
       YAML::Node has a class method call new() that will return a ynode. You
       pass it a regular node and an optional type tag. After that you can use
       it like a normal Perl node, but when you YAML::Dump it, the magical
       properties will be honored.
       This is how you can control the sort order of hash keys during a YAML
       serialization. By default, YAML sorts keys alphabetically. But notice
       in the above example that the keys were Dumped in the same order they
       were assigned.
       YAML::Node exports a function called ynode(). This function returns the
       tied object so that you can call special methods on it like ->keys().
       keys() works like this:
           use YAML;
           use YAML::Node;
           %$node = qw(orange orange apple red grape green);
           $ynode = YAML::Node->new($node);
           ynode($ynode)->keys(['grape', 'apple']);
           print Dump $ynode;
       produces:
           ---
           grape: green
           apple: red
       It tells the ynode which keys and what order to use.
       ynodes will play a very important role in how programs use YAML. They
       are the foundation of how a Perl class can marshall the Loading and
       Dumping of its objects.
       The upcoming versions of YAML.pm will have much more information on
       this.
AUTHOR
       Ingy dot Net <ingy AT cpan.org>
COPYRIGHT
       Copyright 2001-2014. Ingy dot Net
       This program is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.
       See <http://www.perl.com/perl/misc/Artistic.html>;
perl v5.26.3                      2017-10-30                     YAML::Node(3)