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(define-module (closure)
#:export (iterative-add
set-store
peek-store
advance-char))
(define (iterative-add)
"Given NUM, returns NUM plus the previous
supplied NUM."
(let ((prev-num 0))
(lambda num
(let ((result
(+ (car num) prev-num)))
(set! prev-num (car num))
result))))
(define set-store #f)
(define peek-char #f)
(define advance-char #f)
(let ((store '()))
(set! set-store
(lambda (lst)
(set! store lst)))
(set! peek-char
(lambda ()
(car store)))
(set! advance-char
(lambda ()
(let ((ret (car store)))
(set! store (cdr store))
ret))))
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