package Lag;

sub new
{
    my $pkg          = shift;
    my $self         = {};

    $self->{'lapse'} = shift || 441;
    $self->{'disk'}  = [(0) x $self->{'lapse'}];
    $self->{'now'}   = 0;        

    bless $self,$pkg;

    return $self;
} 

sub in
{
    my $self    = shift;
    $self->{'disk'}[$self->{'now'}] = shift;
}

sub out
{
    my $self   = shift;   
    return($self->{'disk'}[$self->{'now'}]);
}

sub pulse
{
    my $self   = shift; 

    $self->{'now'}++;
    $self->{'now'} = 0 if ($self->{'now'} == $self->{'lapse'});
}

'end Lag';