Re: Q: Extending nntp (for nndb)

[Lars Magne Ingebrigtsen <larsi@ifi.uio.no>]

Kai Grossjohann <grossjoh@ls6.informatik.uni-dortmund.de> writes:

>   Lars> By "data", the manual means "data in the nntpd buffer".  I
>   Lars> forgot to mention the function return value.
> 
> I see.  By  reading a bit more, I found that there is in fact one
> function where the return value is mentioned: a list of article
> numbers.  Can I assume that this is the same for other functions?

Nope.  Most of the functions do not return any useful function values,
but the ones that do return useful things all return in different
formats.  For instance, `*-retrieve-headers' return `nov' or
`headers'.  This should be documented better.

> So if I were to add to the nntp.el file a new function, said function
> could just use the variable nntp-address to get the name of the nntp
> server?

Yes.  If you look over the code, most of the functions start with 
`(nntp-possibly-change-server group server)', which deal with all that
gruft.  After calling that function, all variables should be ok.

>   Lars> Yes, probably.  nndb and nntp are sufficiently different that
>   Lars> there probably should be a new nndb.el file.
> 
> Really?  Please note that nndb offers a superset of the nntp protocol.
> Therefore, the nntp subset would have to be maintained twice if the
> two were completely independent nndb.el and nntp.el files.  Well, I
> don't like this idea, but you're the guru, so I'll comply.

Well, I didn't mean that you should rewrite all functions.  Here's
a typical nndir function.  (nndir is a wrapper around nnmh in much the
same way nnbd would be a wrapper around nntp.)

(defun nndir-request-newgroups (date &optional server)
  (nndir-execute-nnmh-command
   `(nnmh-request-newgroups ,date ,server)))

`nndir-execute-nnmh-command' binds the relevant nntp variables and
evals that form.

The main reason that I'd rather not see functions like
`nntp-request-accept-article' is that nntp servers are read-only, and
the presence of such a function would make Gnus believe that Gnus
could delete articles from the nntp backend.  Which isn't really true.

-- 
  "Yes.  The journey through the human heart 
     would have to wait until some other time."