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