#'format knows nothing about files; it only knows about streams, which is what its first argument designates. A point I try to stress with new CL programmers i

#'format knows nothing about files; it only knows about streams, which is what its first argument designates. A point I try to stress with new CL programmers is that if you write new I/O functions to expect a stream designator they're much more flexible than if they expect a pathname.