Re: Will Fitzgerald <fitzgerald@neodesic.com>
Darius Bacon 11 Jan 1999 19:26 UTC
> Michael Sperber <xxxxxx@Informatik.Uni-Tuebingen.De> writes:
> >>>>>> "Will" == Will Fitzgerald <xxxxxx@neodesic.com> writes:
> >
> >Will> May I suggest the following addition to the SRFI-1 list library,
> >Will> Common Lisp's LDIFF:
> >
> >Will> I think a reasonable definition is:
> >Will> [...]
> >[...]
> >Could you suggest possible uses for this procedure?
Here's a fairly trivial use taken from a real program:
(define parse-signature
(lambda (spec)
(let* ((mid (memq '- spec))
(in (list-difference spec mid))
(out (cdr mid)))
(make-signature in out))))
And here's another:
(define (butlast L)
(list-difference L (last-pair L)))
But groveling through my source directories reveals fewer instances of
list-difference than I expected.
-Darius