knight tour in Lispme's scheme

fnkon.scm

;fnkon'
(define (filter f l) 
	(if (null? l) '()
	(let ((x (car l))
		(r (filter f (cdr l))))
	(if (f x) (cons x r) r))))

(define (map f l)
  (letrec ((result (cons '() '()))
	(helper (lambda (p l)
	  (cond ((null? l)  p)
	    (else (set-cdr! p
			(cons (f (car l)) '()))
		(helper (cdr p) (cdr l)))))))
	(helper result l)
	(cdr result)))

(define (make-coord x y)
	(list x y))
	
(define (get-x coord)
	(car coord))
	
(define (get-y coord)
	(cadr coord))
	
(define (on-board? coord)
(if (and (and (> (get-x coord) 0) 
	(<= (get-x coord) 8))
	(and (> (get-y coord) 0) 
	(<= (get-y coord) 8))) #t #f))

(define (neibrs coord)
	(let ((x (get-x coord))
		(y (get-y coord)))
		(list 
		(make-coord (- x 2) (- y 1))
		(make-coord (- x 1) (- y 2))
		(make-coord (+ x 1) (- y 2))
		(make-coord (+ x 2) (- y 1))
		(make-coord (+ x 2) (+ y 1))
		(make-coord (+ x 1) (+ y 2))
		(make-coord (- x 1) (+ y 2))
		(make-coord (- x 2) (+ y 1)))))
				
(define (eq-coords? c1 c2)
    (if (and (= (get-x c1) (get-x c2))
	(= (get-y c1) (get-y c2))) #t #f))
				
(define (coord-in-loc? coord loc)
	;loc - List Of Coordinates
	(cond 
	 ((null? loc) #f)
	 ((eq-coords? coord (car loc)) #t)
	 (else (coord-in-loc? coord (cdr loc)))))

(define (n-o-b coord)
;this makes list of neibrs ON board
	(let ((l-o-neib (neibrs coord)))
	(filter on-board? l-o-neib)))
	 
(define (k-m coord)
(define kml '())
 (letrec ((kml '((1 1) (2 3)))
(lcand (n-o-b coord))
(loop (lambda (lcand) (if (coord-in-loc? (car lcand) kml) (loop (cdr lcand)) (set! kml (append kml (list (car lcand))))))))
(display (car (reverse kml))) 
 (set! kml (append kml (k-m (car (reverse kml)))))))