28 lines
628 B
Racket
28 lines
628 B
Racket
|
#lang racket
|
||
|
|
(define-syntax-rule (And a b)
|
||
|
|
(if b a #f))
|
||
|
|
|
||
|
|
(module+ test
|
||
|
|
(require rackunit)
|
||
|
|
(define (die)
|
||
|
|
(error 'die "don't run this"))
|
||
|
|
|
||
|
|
(check-equal? (And (die) #f) #f)
|
||
|
|
(check-exn exn:fail? (lambda () (and (die) #f))))
|
||
|
|
|
||
|
|
(module+ test
|
||
|
|
(define-syntax-rule (check-fail expr)
|
||
|
|
(check-exn exn:fail? (lambda () expr)))
|
||
|
|
(check-fail (and (die) #f))
|
||
|
|
(check-fail (And #f (die))))
|
||
|
|
|
||
|
|
(define-syntax-rule (Or a b)
|
||
|
|
(or b a))
|
||
|
|
;(if (not a) b #t))
|
||
|
|
|
||
|
|
(module+ test
|
||
|
|
(check-equal? (Or #t #t) #t)
|
||
|
|
(check-equal? (Or #f #t) #t)
|
||
|
|
(check-equal? (Or #t #f) #t)
|
||
|
|
(check-equal? (Or (die) #t) #t)
|
||
|
|
(check-fail (or (die) #t)))
|