🚀 go-pugleaf

Jeff Dalton (jeff@aiai.edinburgh.ac.uk) writes:

  ...  For instance, why should I write code for vectors with as many
  as, say, 1000 elements when I can write instead for "vectors as big
  as this Lisp can handle"?  Why should I have to pick a number?

Well, this probably only works for that particular example, but you
can always build implementation constants into your own type
definitions:

  (DEFTYPE VECTOR-INDEX ()
    '(INTEGER 0 #.(1- ARRAY-TOTAL-SIZE-LIMIT)))

  (DEFUN TRAVERSE-VECTOR (V)
    (DECLARE (TYPE VECTOR V))
    (DOTIMES (I (1- (LENGTH V)))
      (DECLARE (TYPE VECTOR-INDEX I))
      ...
      (ELT V I)
      ...))

I do this all the time.  Then again, by type inference, the compiler
SHOULD be able to figure out the range of I anyway.

John Burger
john@mitre.org