@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...);
}