NAME
    Data::Visitor::Lite - an easy implementation of Data::Visitor::Callback

SYNOPSIS
        use Data::Visitor::Lite;
        my $visitor = Data::Visitor::Lite->new(@replacers);

        my $value = $visitor->visit({ 
          # some structure
        });

DESCRIPTION
    Data::Visitor::Lite is an easy implementation of Data::Visitor::Callback

new(@replacers)
    this is a constructor of Data::Visitor::Lite.

        my $visitor = Data::Visitor::Lite->new(
            [   -implements => ['to_plain_object'] =>
                    sub { $_[0]->to_plain_object }
            ],
            [ -instance => 'Some::SuperClass' => sub { $_[0]->encode_to_utf8 } ]
            [ $replacer_type => $converter ]
        );
        #or

        my $visitor2 = Data::Visitor::Lite->new(sub{
            # callback all node of the structure
        });
        my $value = $visitor->visit({ something });

replacer type
    Data::Visitor::Lite has many expressions to make replacer which is
    applied only specified data type.

  -implements
    If you want to convert only the objects that implements
    'to_plain_object', you can write just following :

        my $visitor = Data::Visitor::Lite->new(
            [   -implements => ['to_plain_object'] => sub {
                    return $_[0]->to_plain_object;
                    }
            ]
        );

    it means it is easy to convert structures using duck typing.

  -instance
    "-instance" replacer type is able to create a converter for all
    instances of some class in the recursive structure.

        my $visitor = Data::Visitor::Lite->new(
            [ -instance => 'Person' => sub{ $_[0]->nickname }]
        );

        $visitor->visit({
            master => Employer->new({ nickname => 'Kenji'}),
            slave  => Employee->new({ nickname => 'Daichi'});
        });

        # { master => "Kenji", slave => 'Daichi'}

  -value
    "-value" means not a reference and/or blessed object.

  -hashkey
    "-hashkey" means key string of the hash reference in the structure.

  -string
    "-string" means hash keys and all string value in the structure.

  -object
    "-object" means a reference and/or blessed object

  other types
    the origin of other replace types is Data::Util.( e.g. glob_ref ,
    scalar_ref, invocant , number ,integer and so on )

AUTHOR
    Daichi Hiroki <hirokidaichi {at} gmail.com>

SEE ALSO
    Data::Visitor::Callback Data::Util

LICENSE
    This library is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.