eval.c:1968
static char*
arg_defined(self, node, buf, type)
    VALUE self;
    NODE *node;
    char *buf;
    char *type;
{
    int argc;
    int i;

    if (!node) return type;	/* no args */
    if (nd_type(node) == NODE_ARRAY) {
	argc=node->nd_alen;
        if (argc > 0) {
	    for (i=0;i<argc;i++) {
		if (!is_defined(self, node->nd_head, buf))
		    return 0;
		node = node->nd_next;
	    }
        }
    }
    else if (!is_defined(self, node, buf)) {
	return 0;
    }
    return type;
}
