///Removes all false and null values from `$list`.
///@ignore Documentation: http://sassylists.com/documentation.html#purge
///@requires sl-is-true
///@requires sl-to-list
///@param {List} $list - list to purge
///@example
///		sl-purge(null a false b)
///		// a b
///@return {List}

@function sl-purge($list) {
  @if sl-missing-dependencies(sl-is-true, sl-to-list) == true { @return null; }
  
  $result: ();

  @each $item in $list {
    @if sl-is-true($item) {
      $result: append($result, $item, list-separator($list));
    }
  }

  @return sl-to-list($result);
}

///@requires sl-purge
///@alias sl-purge
 
@function sl-clean($list) {
  @return sl-purge($list);
}