(define KW_GetWidgetChildren
  (foreign-primitive ((KW_Widget* widget))
    "unsigned int count;\n"
    "C_word av[4] = { C_SCHEME_UNDEFINED, C_k, C_SCHEME_FALSE, C_SCHEME_FALSE} ;"
    "C_word ab[C_SIZEOF_POINTER], *a = ab;"
    "KW_Widget * const * children = KW_GetWidgetChildren(widget, &count);\n"
    "av[2] = C_fix(count);"
    "av[3] = C_a_i_address_to_pointer(&a, 0, (C_word)children);"
    "C_values(4, av);"))

(define (get-children)
  (define extract-child
    (foreign-lambda* ((KW_Widget* children) (int i))
        "C_return(children[i]);"))
  (receive (count child-ptr)
      (let lp ((i 0)
               (children '()))
        (if (= i count)
            children
            (lp (add1 i) (cons (extract-child child-ptr i) children))))))