CODEWITHSUNDEEP
racket
data_pi
data_pi

Reputation: 821

Racket - Check-expect: expects 2 arguments, but found only 1

How do I get around this problem, I've been at it for a while. It keeps giving me this error: check-expect: expects 2 arguments, but found only 1

Its not counting the list as one argument by itself, I think that is the error, but how would I go about fixing this? I've tried doing (count-in cell (list cells)) but it then gives me an error saying define: expected a variable, but found a part

Definitions

(define-struct Cell (x y)

(define (count-in cell cells)
(cond [(member? cell cells) 1]
  [else 0]))

Check-expect, here is where the error comes in

(check-expect (count-in (make-Cell 100 123) 
(list 
(make-Cell 104 123) (make-Cell 45 67)) 
(cond [(member? (make-Cell 100 123)
(list 
(make-Cell 104 123) (make-Cell 45 67)))1] 
  [else 0])1)

Upvotes: 0

Views: 4954

Answers (1)

uselpa
uselpa

Reputation: 18917

This passes your test

(define-struct Cell (x y))

(define (count-in cell cells)
  (cond
    [(member? cell cells) 1]
    [else 0]))

(check-expect
 (count-in (make-Cell 100 123)
           (list (make-Cell 104 123)
                 (make-Cell 45 67)))
 (cond
   [(member? (make-Cell 100 123) (list (make-Cell 104 123) (make-Cell 45 67))) 1] 
   [else 0]))

You should really learn how to indent Scheme code, and use the DrRacket's indentation feature and parenthesis coloring.

Upvotes: 2

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