///Tests whether all items from `$list` pass the test implemented by `$function`.
///@ignore Documentation: http://sassylists.com/documentation.html#sl-every
///@param {List}    $list     - list to run test against
///@param {String}  $function - function to run against every item from list
///@param {ArgList} $args     - extra arguments to pass to the function
///@example
///		sl-every(1 2 3, unitless)
///		// true
///@example
///		sl-every(1 2 3px, unitless)
///		// false
///@return {Bool}

@function sl-every($list, $function, $args...) {
  @each $item in $list {
    @if not call($function, $item, $args...) {
      @return false;
    } 
  }
  
  @return true;
}