32 lines
846 B
Scheme
32 lines
846 B
Scheme
; Convert a char* to a Scheme string
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; Extracted from this paper:
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; http://scheme2011.ucombinator.org/papers/Keep2011.pdf
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(define (char*->string fptr maxsize)
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(let f ([i 0])
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(let ([c (ftype-ref char () fptr i)])
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(if (or (char=? c #\nul) (and (> maxsize 0) (>= i maxsize)))
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(make-string i)
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(let ([str (f (fx+ i 1))])
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(string-set! str i c) str)))))
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(define (string->char* src dest destmax)
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(let ([strlen (string-length src)])
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(let f ([i 0])
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(cond
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((or (>= i strlen) (>= i destmax)) dest)
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(#t
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(ftype-set! char () dest i (string-ref src i))
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(f (fx+ i 1)))))))
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(define (alloc size fx)
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(let ([v (foreign-alloc size)])
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(fx v)
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(foreign-free v)))
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(define (check-err ret msg)
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(cond
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((< ret 0)
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(perror msg)
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(raise msg))
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(#t ret)))
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