[Snow-users-list] snowman-app port problems in Guile
ludo at gnu.org
Tue Apr 15 03:17:16 EDT 2008
Marc Feeley <feeley at iro.umontreal.ca> writes:
> The escapes are generated by the snowfort server. The server, a
> Scheme program, serializes the list of packages using "write" and the
> snowman client will deserialize it using "read". In this case the
> server is running on Gambit and the client is running on Guile.
> Gambit's syntax for strings is compatible with C and the \ooo octal
> notation is how non-ASCII LATIN-1 characters are written. Although
> this syntax is not universal among Scheme implementations, it is a
> fairly common extension to the standard Scheme syntax (supported by
> Bigloo, Chez, Gambit, Kawa, MzScheme, Scsh and probably others).
> Unfortunately Guile does not implement this extension. Note that the
> snowfort server could be run using some other Scheme system, but that
> does not solve the problem because the issue is the incompatibility of
> the server's write and the client's read. That's what standards are
> meant to solve.
Thanks for the explanation.
> So what to do? There is no standard way in Scheme to write non-ASCII
> characters (in fact one could say that no character can be portably
> written since Scheme does not define the character set!). Specific
> serializer/deserializer algorithms other than write/read could be
> implemented but that would be a real pain and it would make I/O really
> slow on interpreted systems.
> The pragmatic solution is to avoid non-ASCII characters in Scheme
> code, and Snow packages in particular.
That's one solution, but as someone with an accent in his name, I don't
like it so much. ;-)
I can think of two solutions:
1. provide a `read' replacement for implementations that are known to
not support this syntax (but as you say, this may result in much
slower I/O, especially on Guile);
2. implement said syntax in Guile.
The latter is doable (and makes sense if everyone else does it), but the
former would allow Snow to run with current versions of Guile.
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