Hi Andreas,
(Sorry for the laaaate reply, I'm just slowly catching up.)
Andreas Rottmann <a.rottm...@gmx.at> skribis:
> Andreas Rottmann <a.rottm...@gmx.at> writes:
>
>> l...@gnu.org (Ludovic Courtès) writes:
>>
>>> Hi Andreas,
>>>
>>> Thanks for taking care of this, and thanks for the great doc too!
>>>
>>> "Andreas Rottmann" <a.rottm...@gmx.at> writes:
>>>
>>>> commit 2252321bb77fe83d98d5bcc9db1c76b914e9dd6a
>>>> Author: Andreas Rottmann <a.rottm...@gmx.at>
>>>> Date: Sat May 7 23:40:14 2011 +0200
>>>>
>>>> Make the R6RS simple I/O library use conditions
>>>>
>>>> * module/rnrs/io/ports.scm (display): Implement as an
>>>> exception-converting wrapper around Guile's core display.
>>>> * module/rnrs/io/simple.scm: Don't export Guile's corresponding core
>>>> procedures, but use `(rnrs io ports)' instead. This way, we get the
>>>> conditions required by R6RS raised.
>>>>
>>>> * doc/ref/r6rs.texi (rnrs io simple): Mention that these procedures are
>>>> supposed to raise R6RS conditions.
>>>
>>> Could you add one or more test cases?
>>>
>> I've started to hack on this, aiming for at least providing tests of a
>> "control sample" of exception-related behaviors in `(rnrs io simple)'
>> and parts of `(rnrs io ports)'. However, as this is already
>> significantly more than one test, it may take a bit. I could however
>> push my existing work at any point, if that's needed for any reason.
>>
> I've now pushed a first patch (b6a66c2), in the process fixing two bugs.
> These were not directly related to the simple I/O change you referenced,
> but located in its base library `(rnrs io ports)'.
+(define (with-i/o-port-error port make-primary-condition thunk)
+ (with-throw-handler 'system-error
+ thunk
+ (lambda args
+ (let ((errno (system-error-errno args)))
+ (if (memv errno (list EIO EFBIG ENOSPC EPIPE))
+ (raise (condition (make-primary-condition)
+ (make-i/o-port-error port)))
+ (apply throw args))))))
+
+(define-syntax with-textual-output-conditions
+ (syntax-rules ()
+ ((_ port body0 body ...)
+ (with-i/o-port-error port make-i/o-write-error
+ (lambda () (with-i/o-encoding-error body0 body ...))))))
[...]
(define (put-char port char)
- (with-i/o-encoding-error (write-char char port)))
+ (with-textual-output-conditions port (write-char char port)))
(define (put-datum port datum)
- (with-i/o-encoding-error (write datum port)))
+ (with-textual-output-conditions port (write datum port)))
I'm a bit concerned about the performance implications of the above
change: ‘put-char’, ‘put-datum’, etc. now expand to something like
(with-i/o-port-error p xxx
(lambda ()
(with-throw-handler 'decoding-error
(lambda ()
(write-char c p))
(lambda (key subr message errno port)
(raise (make-i/o-decoding-error port))))))
So there are at least 4 additional function calls (2
‘with-throw-handler’ calls, and 2 anonymous closure calls.)
Did you do any measurements? Would be nice to add micro-benchmarks
under benchmark-suite/.
One optimization would be to instead do something such that ‘put-char’
would expand to something like:
(define (put-char p c)
(with-throw-handler #t
(lambda ()
(write-char c p))
(lambda args
(case (car args)
((decoding-error)
(raise (make-i/o-decoding-error p)))
((system-error)
(if (memv (system-error-errno args)
`(,EIO ,EFBIG ,ENOSPC ,EPIPE))
...))
(else
;; Not for us.
(apply throw args))))))
What do you think?
Thanks,
Ludo’.
