package Class::Measure::Length;
use 5.008001;
use strict;
use warnings;
our $VERSION = '0.10';

=encoding utf8

=head1 NAME

Class::Measure::Length - Calculate measurements of length.

=head1 SYNOPSIS

    use Class::Measure::Length;
    
    print length( 2, 'km' )->meters();

=cut

use base qw( Class::Measure );

use Sub::Exporter -setup => {
    exports => [qw( length )]
};

=head1 METHODS

This module inherits all the methods made available by
L<Class::Measure>.

=head2 length

    $m = length( 2, 'metres' );

Creates a new measurement object.

=cut

sub length { return __PACKAGE__->new(@_); }

=head1 UNITS

=head2 International System of Units

Also known as SI and "metric", this unit of measure
includes the following.

    kilometre
    metre
    centimetre
    millimetre
    decimetre
    micrometre
    nanometre

And all veriations are aliased, such as "m", "meter",
"meters", "metres".

=cut

__PACKAGE__->reg_units(
    qw( kilometre centimetre millimetre decimetre micrometre nanometre metre )
);
__PACKAGE__->reg_aliases(
    ['kilometer','km','kilometers','kilometres','klick','klicks'] => 'kilometre',
    ['meter','m','meters','metres'] => 'metre',
    ['centimeter','cm','centimeters','centimetres'] => 'centimetre',
    ['millimeter','mm','millimeters','millimetres'] => 'millimetre',
    ['decimeter','decimeters','decimetres'] => 'decimetre',
    ['micrometer','micrometers','micron','microns','micrometres'] => 'micrometre',
    ['nanometer','nanometers','nanometres'] => 'nanometre',
);
__PACKAGE__->reg_convs(
    'km' => 1000, 'm',
    100, 'cm' => 'm',
    10, 'mm' => 'cm',
    'decimetre' => 10, 'cm',
    1000, 'microns' => 'mm',
    1000, 'nanometers' => 'micron',
);

=head2 Shared

These units are shared by with the US and Imperial
unit systems.

    inch
    foot
    yard
    rod
    mile
    chain
    furlong

All relevant aliases included.

=cut

__PACKAGE__->reg_units(
    qw( inch foot yard rod mile chain furlong )
);
__PACKAGE__->reg_aliases(
    ['in','inches'] => 'inch',
    ['feet','ft'] => 'foot',
    'yards' => 'yard',
    ['pole','poles','perch','perches','rods'] => 'rod',
    'miles' => 'mile',
    'chains' => 'chain',
    'furlongs' => 'furlong',
);
__PACKAGE__->reg_convs(
    'inch' => 25.4, 'mm',
    'foot' => 12, 'inches',
    'yard' => 3, 'feet',
    'yard' => 91.44, 'cm',
    'rod' => 16.5, 'feet',
    'mile' => 1.609344, 'km',
    'mile' => 5280, 'feet',
    'chain' => 66, 'feet',
    'furlong' => 10, 'chains',
);

=head2 United Stats

Units specific to the United States.

    survey_mile
    link
    fathom
    cable_length

Aliases included.

=cut

__PACKAGE__->reg_units(
    qw( survey_mile link fathom cable_length )
);
__PACKAGE__->reg_aliases(
    'survey_miles' => 'survey_mile',
    'links' => 'link',
    'fathoms' => 'fathom',
    'cable_lengths' => 'cable_length',
);
__PACKAGE__->reg_convs(
    'survey_mile' => 8, 'furlongs',
    'link' => 0.001, 'furlongs',
    'fathom' => 6, 'feet',
    'cable_length' => 123, 'fathoms',
);

=head2 Imperial

Imperial (english) units.  The only unit included
in this set is "league".

=cut

__PACKAGE__->reg_units(
    qw( league )
);
__PACKAGE__->reg_aliases(
    'leagues' => 'league',
);
__PACKAGE__->reg_convs(
    'league' => 3, 'miles',
);

=head2 Other

    light_second
    nautical_mile

=cut

__PACKAGE__->reg_units(
    qw( light_second nautical_mile )
);
__PACKAGE__->reg_aliases(
    'light_seconds'  => 'light_second',
    'nautical_miles' => 'nautical_mile',
);
__PACKAGE__->reg_convs(
    'light_second'  => 299792458, 'm',
    'nautical_mile' => 1852, 'm',
);

1;
__END__

=head1 SUPPORT

See L<Class::Measure/SUPPORT>.

=head1 AUTHORS

See L<Class::Measure/AUTHORS>.

=head1 LICENSE

See L<Class::Measure/LICENSE>.

=cut