Re: gnus should accept UTF8 even if UTF-8 is standard

[Stephen J. Turnbull]

Eli Zaretskii writes:

 > >  > That implies that the return value would be a string, not the coding
 > >  > system itself.  I suggest we return the coding system (or nil), not
 > >  > just the name.
 > > 
 > > The coding system *is* just a name
 > 
 > Not in GNU Emacs; see the doc string of `define-coding-system' (in
 > Emacs 23) or `make-coding-system' (in Emacs 22).

If that's true, it's a shame; AFAICS there is no real utility to
exposing the coding system object to Lisp, since you never want to
muck with one in the middle of en/decoding, and the codecs themselves
aren't defined in Lisp anyway (they're defined either in C or CCL).
Not to mention that I don't see how you can dispense with
`get-coding-system' if you need to actually get a coding system
object.

But I thought that that is something that got fixed in Emacs 21 or 22.
So coding system objects and charset objects are no longer visible to
Lisp, but rather are manipulated by functions whose arguments include
the name of the object.  No?

 > >  > Some time back in this thread I suggested
 > >  > `coding-system-for-charset' (since the argument strings will
 > >  > be charsets).
 > > 
 > > Actually, if I recall the thread correctly, normally they won't.
 > > They'll be *MIME* charsets, which correspond to Emacs *coding
 > > systems*.
 > 
 > "utf8" is not a MIME charset, AFAIK, and it certainly doesn't
 > currently correspond to any coding system in Emacs.

"utf8" is not a MIME charset (and no form of UTF-8 is an Emacs
charset), but "utf-8" is an IANA-registered MIME charset.  AIUI, the
point of the function is to guess what people who don't know what
they're doing are trying to express (and to provide some interactive
convenience to people who do know what they're doing).