@function __base-functions($map, $props) {
  $result: ();

  @each $key in $props {
    @if __function-exists(__get($map, $key)) {
      $result: append($result, $key);
    }
  }

  @return $result;
}

@function __functions($map) {
  @return __base-functions($map, __keys-in($map));
}

/// Creates a list of function property names from all enumerable properties,
/// own and inherited, of `$map`.
///
///
/// @access public
/// @group Map
/// @param {Map} $map The map to inspect.
/// @returns {List} Returns the new list of property names.
/// @example scss
/// $map: ('a': '_after', 'b': 'lighten', 'c': 'blah');
///
/// $foo: _functions($map);
/// // => ('a', 'b')

@function _functions($args...) {
  @return call(get-function("__functions"), $args...);
}

/// @alias _functions

@function _methods($args...) {
  @return call(get-function("__functions"), $args...);
}