File Coverage

blib/lib/Math/Random/MT.pm

Criterion	Covered	Total	%
statement	43	43	100.0
branch	13	14	92.8
condition	8	8	100.0
subroutine	12	12	100.0
pod	5	5	100.0
total	81	82	98.7

package Math::Random::MT;

use strict;
use Carp;
use DynaLoader;
use vars qw( @ISA $VERSION );

my $gen = undef;
@ISA = qw( DynaLoader );
$VERSION = '1.17';

bootstrap Math::Random::MT $VERSION;

sub new
{
    my ($class, @seeds) = @_;

    my $self = Math::Random::MT::init();
    $self->set_seed(@seeds);

    return $self;
}

sub set_seed
{
    my ($self, @seeds) = @_;
    @seeds > 1 ? $self->setup_array(@seeds) :
                 $self->init_seed(defined $seeds[0] ? $seeds[0] : _rand_seed());
    return $self->get_seed;
}

sub srand
{
    my (@seeds) = @_;
    $gen = Math::Random::MT->new(@seeds);
    return $gen->get_seed;
}

sub rand
{
    my ($self, $N) = @_;

    unless (ref $self) {
        $N = $self;
        Math::Random::MT::srand() unless defined $gen;
        $self = $gen;
    }

    return ($N || 1) * $self->genrand();
}

sub irand
{
    my ($self) = @_;

    unless (ref $self) {
        Math::Random::MT::srand() unless defined $gen;
        $self = $gen;
    }

    return $self->genirand();
}


# Generate a random seed using the built-in PRNG.

sub _rand_seed {
    my ($self) = @_;

    # Get a seed at random through Perl's CORE::rand(). We do not call
    # CORE::srand() to avoid altering the random numbers that other parts of
    # the running script might be using. The seeds obtained by rapid calls to
    # the _rand_seed() function are all different.

    return int(CORE::rand(2**32));
}

sub import
{
    no strict 'refs';
    my $pkg = caller;
    foreach my $sym (@_) {
        if ($sym eq 'srand' || $sym eq 'rand' || $sym eq 'irand') {
            *{"${pkg}::$sym"} = \&$sym;
        }
    }
}

1;

__END__