oocss whitespace in sass

@mixin	whitespace($sizes: (5, 10, 20)){ //for now assume this list is always ascending
	if length($sizes = 1){

	} @else if length($sizes = 2) {

	}
	$types: (p,m);
	$locations: (a, v, h, t, r, b, l);
	$key: (p padding, m margin, a, v -top -bottom, h -left -right, t -top, r -right, b -bottom, l -left);
	@each $location in $locations {
		@each $size in $sizes {
			@each $type in $types {
				.#{$location}#{$size}#{$type}{
					padding-top:10px;
				}
			}
		}
	}
}