代码: 全选
;;假定已经有一个判断一个数是否是质数的函数prime?。
(define (filter-accumulate combiner null-value term a next b filter)
(define (iter a null-value)
(cond ((> a b) null-value)
((filter a) (iter (next a) (combiner (term a) null-value)))
(else (iter (next a) null-value ))))
(iter a null-value))
(filter-accumulate + 0 (lambda (x) x) 3 (lambda (x) (+ x 1)) 100 prime?)