NAME

Class::Enum - typed enum

SYNOPSIS

Simple usage.

Define `Direction`,

# Direction.pm
package Direction;
use Class::Enum qw(Left Right);

and using.

# using
use Direction qw(Left Right);

# default properties
print Left ->name; # 'Left'
print Right->name; # 'Right
print Left ->ordinal; # 0
print Right->ordinal; # 1

print Left ->is_left;  # 1
print Left ->is_right; # ''
print Right->is_left;  # ''
print Right->is_right; # 1

# compare by ordinal
print Left() <=> Right; # -1
print Left() <   Right; # 1
print Left() <=  Right; # 1
print Left() >   Right; # ''
print Left() >=  Right; # ''
print Left() ==  Right; # ''
print Left() !=  Right; # 1

# compare by name
print Left() cmp Right; # -1
print Left() lt  Right; # 1
print Left() le  Right; # 1
print Left() gt  Right; # ''
print Left() ge  Right; # ''
print Left() eq  Right; # ''
print Left() ne  Right; # 1

# list values
print join("\n",                                                 # '0: Left
           map { sprintf('%d: %s', $_, $_) } Direction->values); #  1: Right'

# list names
print join(', ', Direction->names); # 'Left, Right'

# retrieve value of name
print Left() == Direction->value_of('Left'); # 1

# retrieve value of ordinal
print Left() == Direction->from_ordinal(0); # 1

# type
print ref Left; # 'Direction'

Advanced usage.

Define `Direction`,

# Direction.pm
package Direction;
use Class::Enum (
    Left  => { delta => -1 },
    Right => { delta =>  1 },
);

sub move {
    my ($self, $pos) = @_;
    return $pos + $self->delta;
}

and using.

# using
use Direction qw(Left Right);

my $pos = 5;
print Left->move($pos);  # 4
print Right->move($pos); # 6

Override default properties. (Unrecommended)

Define `Direction`,

# Direction.pm
package Direction;
use Class::Enum (
    Left   => { name => 'L', ordinal => -1 },
    Center => { name => 'C' }
    Right  => { name => 'R' },
);

and using.

# using
use Direction qw(Left Center Right);

my $pos = 5;
print $pos + Left;   # 4
print $pos + Center; # 5
print $pos + Right;  # 6

print 'Left is '   . Left;   # 'Left is L'
print 'Center is ' . Center; # 'Center is C'
print 'Right is '  . Right;  # 'Right is R'

Override overload

Define `Direction`,

# Direction.pm
package Direction;
use Class::Enum qw(Left Right), -overload => { '""' => sub { $_[0]->ordinal } };

and using.

# using
use Direction qw(Left Right);
print 'Left is '  . Left;  # 'Left is 0'
print 'Right is ' . Right; # 'Right is 1'

Use alternate exporter.

Define `Direction`,

# Direction.pm
package Direction;
use Class::Enum qw(Left Right), -install_exporter => 0; # No install 'Exporter'
use parent 'Exporter::Tiny';
our @EXPORT_OK = __PACKAGE__->names();

and using.

# using
use Direction Left  => { -as => 'L' },
              Right => { -as => 'R' };

print L->name; # 'Left'
print R->name; # 'Right

DESCRIPTION

Class::Enum provides behaviors of typed enum, such as a Typesafe enum in java.

LICENSE

Copyright (C) keita.iseki.

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

AUTHOR

keita.iseki <keita.iseki+cpan at gmail.com>

cpanm Class::Enum

perl -MCPAN -e shell
install Class::Enum