Greetings Scheme poets!
So, I wrote a `copy-file' procedure (using just the information found in
the R7RS PDF) that copies a file *byte-by-byte*:
(define (copy-file source destination)
"Copy SOURCE file as DESTINATION file."
(let ((source (open-binary-input-file source))
(destination (open-binary-output-file destination)))
(do ((byte (read-u8 source) (read-u8 source)))
((eof-object? byte))
(write-u8 byte destination))
(close-port source)
(close-port destination)))
The procedure worked on the first try in both Guile and s7. Happy, I
decided to make the procedure copy *megabyte-by-megabyte* to make it
faster:
(define (copy-file source destination)
"Copy SOURCE file as DESTINATION file."
(let ((buffer-size (* 1024 1024))
(source (open-binary-input-file source))
(destination (open-binary-output-file destination)))
(do ((buffer (bytevector) (read-bytevector buffer-size source)))
((eof-object? buffer))
(write-bytevector buffer destination))
(close-port source)
(close-port destination)))
The procedure, again, worked on the first try in Guile, and it indeed
copied files much faster. However, in s7, the procedure seems to never
return! I waited for a couple of minutes, copying a 5-megabyte file.
Have I stumbled upon a bug in s7 (or `r7rs.scm' that defines the R7RS
byte-vector procedures), or have I written the procedure incorrectly?
Rudy
--
"'Contrariwise,' continued Tweedledee, 'if it was so, it might be; and
if it were so, it would be; but as it isn't, it ain't. That's logic.'"
-- Lewis Carroll, Through the Looking Glass, 1871/1872
Rudolf Adamkovič <[email protected]> [he/him]
Studenohorská 25
84103 Bratislava
Slovakia
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