(define KW_GetWidgetChildren (foreign-safe-lambda* scheme-object ((KW_Widget* widget))
                               "C_word lst = C_SCHEME_END_OF_LIST;\n"
                               "C_word *p = C_alloc(C_SIZEOF_POINTER);\n"
                               "unsigned int count;\n"
                               "KW_Widget * const * children = KW_GetWidgetChildren(widget, &count);\n"
                               "if (!count) {\n"
                               "  C_return(lst);\n"
                               "}\n"
                               "for (int i = 0; i < count; i++) {\n"
                               "  C_word *a = C_alloc(C_SIZEOF_PAIR);\n"
                               "  KW_Widget *child = children[i];\n"
                               "  C_a_i_address_to_pointer(&p, 0, (C_word) child);\n"
                               "  lst = C_a_pair(&a, *p, lst);\n"
                               "}\n"
                               "C_return(lst);"))

(define (widget-children widget)
  (and-let* ((widget* (widget-pointer widget)))
    (let ((children* (KW_GetWidgetChildren widget*)))
      (map (cut hash-table-ref widget-table <>) children*))))