NAME

Data::Monad::Singleton - The singleton monad.

SYNOPSIS

  use Data::Monad::Singleton;

  my $singleton = Data::Monad::Singleton->unit("Hello")
                                        ->flat_map(sub { length $_[0] });

  $singleton == singleton and die "All operations are ignored.";

DESCRIPTION

Data::Monad::Singleton maps all values to the one value. It collapses the structure of original computations.

METHODS

$m = singleton;

Represents the value of this class.

$m = Data::Monad::Singleton->new;

Represents the value of this class.

unit

flat_map

Overrides methods of Data::Monad::Base::Monad.

AUTHOR

hiratara <hiratara {at} cpan.org>

SEE ALSO

Data::Monad::Base::Monad

LICENSE

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