django-compass-mixins/compass_mixins/static/breakpoint/parsers/_query.scss

@function breakpoint-parse-query($query) {
  // Parse features out of an individual query
  $feature-holder: ();
  $query-holder: ();
  $length: length($query);

  @if $length == 2 {
    // If we've got a string/number, number/string, check to see if it's a valid string/number pair or two singles
    @if (type-of(nth($query, 1)) == 'string' and type-of(nth($query, 2)) == 'number') or (type-of(nth($query, 1)) == 'number' and type-of(nth($query, 2)) == 'string') {

      $number: '';
      $value: '';

      @if type-of(nth($query, 1)) == 'string' {
        $number: nth($query, 2);
        $value: nth($query, 1);
      }
      @else {
        $number: nth($query, 1);
        $value: nth($query, 2);
      }

      // If the string value can be a single value, check to see if the number passed in is a valid input for said single value. Fortunately, all current single-value options only accept unitless numbers, so this check is easy.
      @if breakpoint-single-string($value) {
        @if unitless($number) {
          $feature-holder: append($value, $number, space);
          $query-holder: append($query-holder, $feature-holder, comma);
          @return $query-holder;
        }
      }
      // If the string is a media type, split the query
      @if breakpoint-is-media($value) {
        $query-holder: append($query-holder, nth($query, 1));
        $query-holder: append($query-holder, nth($query, 2));
        @return $query-holder;
      }
      // If it's not a single feature, we're just going to assume it's a proper string/value pair, and roll with it.
      @else {
        $feature-holder: append($value, $number, space);
        $query-holder: append($query-holder, $feature-holder, comma);
        @return $query-holder;
      }

    }
    // If they're both numbers, we assume it's a double and roll with that
    @else if (type-of(nth($query, 1)) == 'number' and type-of(nth($query, 2)) == 'number') {
      $feature-holder: append(nth($query, 1), nth($query, 2), space);
      $query-holder: append($query-holder, $feature-holder, comma);
      @return $query-holder;
    }
    // If they're both strings and neither are singles, we roll with that.
    @else if (type-of(nth($query, 1)) == 'string' and type-of(nth($query, 2)) == 'string') {
      @if not breakpoint-single-string(nth($query, 1)) and not breakpoint-single-string(nth($query, 2)) {
        $feature-holder: append(nth($query, 1), nth($query, 2), space);
        $query-holder: append($query-holder, $feature-holder, comma);
        @return $query-holder;
      }
    }
  }
  @else if $length == 3 {
    // If we've got three items and none is a list, we check to see
    @if type-of(nth($query, 1)) != 'list' and type-of(nth($query, 2)) != 'list' and type-of(nth($query, 3)) != 'list' {
      // If none of the items are single string values and none of the values are media values, we're good.
      @if (not breakpoint-single-string(nth($query, 1)) and not breakpoint-single-string(nth($query, 2)) and not breakpoint-single-string(nth($query, 3))) and  ((not breakpoint-is-media(nth($query, 1)) and not breakpoint-is-media(nth($query, 2)) and not breakpoint-is-media(nth($query, 3)))) {
        $feature-holder: append(nth($query, 1), nth($query, 2), space);
        $feature-holder: append($feature-holder, nth($query, 3), space);
        $query-holder: append($query-holder, $feature-holder, comma);
        @return $query-holder;
      }
      // let's check to see if the first item is a media type
      @else if breakpoint-is-media(nth($query, 1)) {
        $query-holder: append($query-holder, nth($query, 1));
        $feature-holder: append(nth($query, 2), nth($query, 3), space);
        $query-holder: append($query-holder, $feature-holder);
        @return $query-holder;
      }
    }
  }

  // If it's a single item, or if it's not a special case double or triple, we can simply return the query.
  @return $query;
}