Example of control directives in SCSS

control_directives.scss

i {
	$positions: (izq, der);
	$colors: (w, b);
	@for $i from 1 through 2 {
		@each $position in $positions {
			@each $color in $colors {
				&.#{ $position }_0#{ $i }_#{ $color } {
					@include fx_item(#{ $position }_0#{ $i }_#{ $color });
				}
			}
		}
	}
}