Reverses a CSS direction, accepting a single direction or a list.

example

.media {
  @each $dir in left, right {
    .pull-#{$dir} {
      margin-#{opposite-direction($dir)}: $padding-base-horizontal;
    }
  }
}

SASS opposite direction function

@function get-opposite-direction($direction) {
  $opposite-direction: center;

  @if $direction == top {
    $opposite-direction: bottom;
  }
  @if $direction == bottom {
    $opposite-direction: top;
  }
  @if $direction == left {
    $opposite-direction: right;
  }
  @if $direction == right {
    $opposite-direction: left;
  }

  @return $opposite-direction;
}

@function opposite-direction($direction) {
  $opposite-direction: null;

  @if length($direction) == 1 {
    $opposite-direction: get-opposite-direction($direction);
  } @else {
    @for $i from 1 through length($direction) {
      $opposite-direction: append($opposite-direction, get-opposite-direction(nth($direction, $i)));
    }
  }

  @return $opposite-direction;
}