Position mixin

position.scss

@mixin position ($pos: relative, $coords: 0 0 0 0) {
  @if type-of($pos) == list {
    $coords: $pos;
    $pos: relative;
  }

  $length: length($coords);
  position: $pos;

  @if $length > 0 { top:    nth($coords, 1); }
  @if $length > 1 { right:  nth($coords, 2); }
  @if $length > 2 { bottom: nth($coords, 3); }
  @if $length > 3 { left:   nth($coords, 4); }
}

// Usage
// -----

@include position(absolute, 10px 0 0 0);
@include position(10px);
@include position(null null 10px);