cssass - margin calculator tabajara

$distanceBase = 8px;

//Padding mixin
@mixin padding($top:null, $right:null, $bottom:null, $left:null) 
{
    padding: calcDistance($top) calcDistance($right) calcDistance($bottom) calcDistance($left);
}

//Margin mixin
@mixin margin($top:null, $right:null, $bottom:null, $left:null) 
{
    margin: calcDistance($top) calcDistance($right) calcDistance($bottom) calcDistance($left);
}

@function calcDistance($distance)
{
    @if $distance == null or $distance == 0 {
        @return $distance;
    }

    @return $distance*$distanceBase;
}