35 lines
826 B
Scheme
35 lines
826 B
Scheme
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(define (marker-finder step not-found found port marker remaining)
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(let [(r (get-char port))]
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(cond
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((eof-object? r) (not-found))
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((char=? r (car remaining))
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(step
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r
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(cond
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((null? (cdr remaining)) (found))
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(#t (marker-finder step not-found found port marker (cdr remaining))))))
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(#t (step r (marker-finder step not-found found port marker marker)))
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)))
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(define (read-until port marker)
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(list->string
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(marker-finder
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(lambda (e r) (cons e r))
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(lambda () '())
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(lambda () '())
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port
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(string->list marker)
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(string->list marker)
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)))
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(define (seek-until port marker)
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(marker-finder
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(lambda (e r) r)
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(lambda () #f)
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(lambda () #t)
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port
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(string->list marker)
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(string->list marker)
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))
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