db/private/mysql/connection.rkt does not export the function, otherwise you could.
On Jun 11, 2013, at 4:26 PM, David Vanderson wrote: > Thank you Stephen and Tony for your examples. I found the following private > function in db/private/mysql/connection.rkt: > > (define (hex-string->bytes s) > (define (hex-digit->int c) > (let ([c (char->integer c)]) > (cond [(<= (char->integer #\0) c (char->integer #\9)) > (- c (char->integer #\0))] > [(<= (char->integer #\a) c (char->integer #\f)) > (+ 10 (- c (char->integer #\a)))] > [(<= (char->integer #\A) c (char->integer #\F)) > (+ 10 (- c (char->integer #\A)))]))) > (unless (and (string? s) (even? (string-length s)) > (regexp-match? #rx"[0-9a-zA-Z]*" s)) > (raise-type-error 'hex-string->bytes > "string containing an even number of hexadecimal digits" > s)) > (let* ([c (quotient (string-length s) 2)] > [b (make-bytes c)]) > (for ([i (in-range c)]) > (let ([high (hex-digit->int (string-ref s (+ i i)))] > [low (hex-digit->int (string-ref s (+ i i 1)))]) > (bytes-set! b i (+ (arithmetic-shift high 4) low)))) > b)) > > > Can this function be exported? I'm willing to make a patch with docs and > tests - is file/sha1 the right place? > > Thanks, > Dave > > _________________________ > Racket Developers list: > http://lists.racket-lang.org/dev _________________________ Racket Developers list: http://lists.racket-lang.org/dev