Re: connected?

dvanhorn wrote:
> (define between?

Let me try again:

;; Returns true if any of the pieces are between x and y.
;; (row * col) * (row * col) * list of (row * col) -> bool

(define between?
  (let ((f (lambda (x y)
             (if (= x y) (circular-list x)
                 (list-tabulate (sub1 (abs (- x y)))
                                (lambda (z) ((if (< x y) + -) x z 1)))))))
    (match-lambda*
      [((x-row x-col) (y-row y-col) pieces)
       (any (lambda (x) (in? x pieces))
            (zip (f x-row y-row)
                 (f x-col y-col)))])))

Nicer?

(NB There is a bug in MzScheme's implementation of SRFI; zip on infinite lists
does not work.)

David