File Coverage

blib/lib/Date/Easy/Units.pm

Criterion	Covered	Total	%
statement	52	53	98.1
branch	7	8	87.5
condition			n/a
subroutine	22	23	95.6
pod	9	9	100.0
total	90	93	96.7

package Date::Easy::Units;

use strict;
use warnings;
use autodie;

our $VERSION = '0.09'; # VERSION

use Carp;

use Exporter;
use parent 'Exporter';
my @date_units = qw< days weeks months years >;
my @datetime_units = (qw< seconds minutes hours >, @date_units);
our @EXPORT_OK = @datetime_units;
our %EXPORT_TAGS = ( date => \@date_units, datetime => \@datetime_units, all => \@EXPORT_OK );


##############################
# FUNCTIONS (*NOT* METHODS!) #
##############################

sub seconds () { __PACKAGE__->new("seconds") }
sub minutes () { __PACKAGE__->new("minutes") }
sub hours   () { __PACKAGE__->new("hours")   }
sub days    () { __PACKAGE__->new("days")    }
sub weeks   () { __PACKAGE__->new("weeks")   }
sub months  () { __PACKAGE__->new("months")  }
sub years   () { __PACKAGE__->new("years")   }


#######################
# REGULAR CLASS STUFF #
#######################

sub new
{
	my ($class, $unit, $qty) = @_;
	if (defined $qty)
	{
		croak("can only do integer math") unless $qty == int($qty);
	}
	else
	{
		$qty = 1;
	}
	return bless { qty => $qty, unit => $unit }, $class;
}


sub to_string
{
	my $self = shift;

	my $qty  = $self->{qty};
	my $unit = $self->{unit};
	$unit =~ s/s$// if $qty == 1;
	return "$qty $unit";
}


########################
# OVERLOADED OPERATORS #
########################

sub _add_to
{
	my ($self, $operand) = @_;
	my $unit = $self->{unit};
	my $qty  = $self->{qty};
	my $method = "add_$unit";
	return $operand->$method($qty);
}

sub _subtract_from
{
	my ($self, $operand) = @_;
	my $unit = $self->{unit};
	my $qty  = $self->{qty};
	my $method = "subtract_$unit";
	return $operand->$method($qty);
}

use overload
	'""'	=>	sub { shift->to_string },
	'cmp'	=>	sub { $_[0]->to_string cmp $_[1] },

	'+'		=>	sub { shift->_add_to( @_ ) },
	'-'		=>	sub { $_[2] ? shift->_subtract_from( @_ ) : croak("can't subtract from a unit") },
	'*'		=>	sub { __PACKAGE__->new( $_[0]->{unit}, $_[0]->{qty} * $_[1] ) },
;



1;



# ABSTRACT: units objects for easy date/datetime math
# COPYRIGHT

__END__