20 lines
368 B
Scheme
20 lines
368 B
Scheme
(define (odd)
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(let ((c (read-char)))
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(if (char-alphabetic? c)
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(let ((r (odd)))
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(write-char c)
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r)
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(lambda () (write-char c) (char=? c #\.)))))
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(define (even)
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(let ((c (read-char)))
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(write-char c)
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(if (char-alphabetic? c)
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(even)
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(char=? c #\.))))
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(let loop ((i #f))
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(if (if i ((odd)) (even))
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(exit)
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(loop (not i))))
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