摘要： 设计原则：约定的界面（conventional interfaces）。范例：“流结构”化的 sum-odd-squares 和 even-fibs 1 (define (filter predicate sequence) 2 (cond ((null? sequence) '()) 3 ((predicate (car sequence)) 4 (cons (car sequence) 5 (filter predicate (cdr sequence)))) 6 (else (filter... 阅读全文