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