Question

I was given this bit of Scheme code, and have been tasked with translating the code into Perl.

(define (makecounter)
 (let ((x 0)) (lambda () (begin (set! x (+ x 1)) x))))

I know this is supposed to be a closure function, but I’m can’t quite get what this is supposed to be doing. Any ideas?

Answer 1

Hint:

(define c1 (makecounter))
(define c2 (makecounter))
(c1)
=> 1
(c1)
=> 2
(c1)
=> 3
(c2)
=> 1
(c2)
=> 2
(c1)
=> 4