Need foreign string method for translate-into-foreign-memory?

[Liam Healy]

On Sat, Oct 12, 2013 at 6:52 AM, Luís Oliveira
<loliveira at common-lisp.net> wrote:
> On Wed, Oct 9, 2013 at 4:35 AM, Liam Healy <lnp at healy.washington.dc.us> wrote:
>> I've pushed the rewrite; please take a look and run tests to see
>> that it's good. I've temporarily created a new branch foreign-string.
>
> This refactorization is trickier than it might seem. You cannot pass
> the string to the octet-counter without performing the
> with-checked-simple-vector adjustments beforehand. Also, this version
> doesn't take into account the null terminator when computing the right
> bound of the buffer.
>
> I'd start over and try to extract the encoder funcall and the null
> terminator loop, make sure that works, and then try to figure out
> what's the next lowest hanging fruit.
>
> Cheers,
>
> --
> Luís Oliveira
> http://kerno.org/~luis/

OK. This has already exceeded my available skills, time, and interest,
so I will leave those two functions as-is and go back to the original
task, which was to create a translate-into-foreign-memory method for
foreign-string-type. How does this look?

(defmethod translate-into-foreign-memory
    ((string string) (type foreign-string-type) pointer)
  (check-type string string)
  (with-checked-simple-vector ((string (coerce string 'babel:unicode-string))
                               (start 0) (end nil))
    (declare (type simple-string string) (ignore start end))
    (let* ((encoding (fst-encoding type))
           (length
             (+ (funcall (octet-counter (lookup-mapping
*foreign-string-mappings* encoding))
                         string 0 nil 0)
                (null-terminator-len encoding))))
      (lisp-string-to-foreign string pointer length))))

Thanks,
Liam