[slime-devel] Re: sbcl regression with slime

[Daniel Pittman]

On 20 Nov 2004, Christophe Rhodes wrote:
> Helmut Eller <e9626484 at stud3.tuwien.ac.at> writes:
>
>> I added support for multibyte coding systems.  The new magic variable
>> is slime-net-coding-system. Currently there are 3 possible values for
>> the coding system: iso-8859-1-unix, utf-8-unix, and emacs-mule-unix.
>> At startup, Emacs tells the Lisp implementation which coding system to
>> use and same encoding is used for the rest of the session.  Not all
>> Lisps implementations support all coding systems.  The situations is
>> as follows:
>>
>> CMUCL, OpenMCL: support only iso-8859-1-unix.
>> SBCL, CLISP: can be used with iso-8859-1-unix or utf-8-unix.
>> Allegro: supports all three.
>
> Thank you.  What Lisp support do you need to support other external
> formats?  A lisp-side understanding of the emacs multibyte system?
>
> If so, where is emacs-mule-unix documented?

`emacs-mule' is an internal coding system -- *not* something that you
really want to use for communications between (X)Emacs and another
process.

One key reason for this is that this encoding has been known to change
from version to version of Emacs itself -- as the needs of the internal
data storage system change, at least under XEmacs.  I believe that GNU
Emacs has done the same, notably with the addition of some Unicode
support around the 21.3 release.

Supporting utf-8 is good, and is available (for many characters) through
the mule-ucs package, or internal support, under recent Emacs and XEmacs
versions.

This package provides a CCL based tool for translating utf-8 into the
internal Mule encoding and vice-versa, insulating you from the details
of the internal coding.

Supporting the various 8-bit ISO encodings (other than 8859-1) is
probably also nice, but not that necessary with utf-8 support.

If you really want something that isn't Unicode, but that does support a
variety of coding systems at once, one of the real ISO-2022 encodings is
what you want -- something standard that allows selecting the active
character set, without the random variation of the internal Mule
encoding.

Regards,
        Daniel

-- 
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