The source file encoding should be a property of the port (as is the
case-folding property). It could be set with a "#!" directive (at the
top of the file).

-- Marc

Am So., 12. Mai 2019 um 14:06 Uhr schrieb Shiro Kawai <xxxxxx@gmail.com>:
>
> 'read' can occur strictly before interpreting any of S-expressions, and reading in incorrect encoding can
> cause an I/O error so you may not have a chance to interpret those forms.
> Technically the encoding info should be a metadata of a file, not in the content of the file, so the "coding" comment
> is certainly a kluge.  What I thought is that it might be useful to codify the current practice.
>
> BTW, the "magic encoding comment" is supported in a few languages:
>
> Python: https://www.python.org/dev/peps/pep-0263/
> Ruby: https://idiosyncratic-ruby.com/26-file-encoding-magic.html
>
>
>
>
>
> On Sun, May 12, 2019 at 1:50 AM Lassi Kortela <xxxxxx@lassi.io> wrote:
>>
>> > have problems that do not occur with comment parsing (e.g. when using
>> > non-ASCII-superset multi-byte encodings such as UTF-16 or Shift-JIS)?
>>
>> I had that wrong -- from skimming Wikipedia, Shift JIS, EUC-* and Big5
>> are almost strictly ASCII-compatible in the 0..127 range (trail bytes
>> that can overlap ASCII characters are almost the only exception).
>>
>> Would it be problematic to read the first S-expression from a Shift JIS
>> / EUC-* / Big5 coded source file assuming that it's (extended) ASCII?
>> Then if that form is something like:
>>
>>      (declare-file
>>        (coding "Shift_JIS")
>>        ...possibly other declarations here...)
>>
>> The file would be read again as Shift_JIS?

--
Prof. Dr. Marc Nieper-Wißkirchen

Universität Augsburg
Institut für Mathematik
Universitätsstraße 14
86159 Augsburg

Tel: 0821/598-2146
Fax: 0821/598-2090

E-Mail: xxxxxx@math.uni-augsburg.de
Web: www.math.uni-augsburg.de/alg/mitarbeiter/mnieper/