LINUX.ORG.RU

История изменений

Исправление x4DA, (текущая версия) : 

#lang racket

(define-syntax (at-least-two stx)
  (syntax-case stx ()
    [(_ args ...) 
     #'(eq? 2 (for/fold ([c 0]) ([x (syntax->list #'(args ...))] 
                   #:break (eq? c 2))
              (if (eval (syntax->datum x))
                  (+ c 1) c)))]))

(printf "first: ~a\n"  (at-least-two 
                      (eq?  1 1) 
                      (eq?  3 2) 
                      (eq?  2 5)
                      (eq?  2 20)))

(printf "second: ~a\n" (at-least-two 
                            (eq? 1 1)
                            (eq? 3 2)
                            (eq? 5 5)
                            (eq? 2 20)))

Исправление x4DA, : 

#lang racket

(define-syntax (at-least-two stx)
  (syntax-case stx ()
    [(_ args ...) 
     #'(eq? 2 (for/fold ([c 0]) ([x (syntax->list #'(args ...))] 
                   #:break (eq? c 2))
              (if (eval (syntax->datum x))
                  (+ c 1) c)))]))

(printf "first: ~a\n"  (at-least-two (eq?  1 1) 
                      (eq?  3 2) 
                      (eq?  2 5)
                      (eq?  2 20)))

(printf "second: ~a\n" (at-least-two (eq? 1 1)
                            (eq? 3 2)
                            (eq? 5 5)
                            (eq? 2 20)))

Исходная версия x4DA, : 

#lang racket

(define-syntax (at-least-two stx)
  (syntax-case stx ()
    [(_ args ...) 
     #'(eq? 2 (for/fold ([c 0]) ([x (syntax->list #'(args ...))] 
                   #:break (eq? c 2))
              (if (eval (syntax->datum x))
                  (+ c 1) c)))]))

(printf "first: ~a\n"  (at-least-two 
                      (eq?  1 1) 
                      (eq?  3 2) 
                      (eq?  2 5)
                      (eq?  2 20)))

(printf "second: ~a\n" (at-least-two (eq? 1 1)
                            (eq? 3 2)
                            (eq? 5 5)
                            (eq? 2 20)))