How to add new split method?

How to add new split method?

[Kai.Grossjohann]

Suppose I had a function which could split some of the incoming
messages but not all of them.  Thus, the behavior I want is:

If nnmail-kai-split-smartly returns a group, split the incoming
message to that group, else process nnmail-split-methods normally.

I'm also willing to use nnmail-split-fancy, of course, if that helps.

The documentation for nnmail-split-fancy tells me that it is possible
to call functions, but it is not clear whether the function is allowed
to return a don't-know value whereupon the processing of
nnmail-split-fancy continues.

Maybe I can just make the function return NIL as a don't-know value?
The documentation doesn't say, and I don't grok the source.

kai
-- 
Life is hard and then you die.

Re: How to add new split method?

[Michael Welsh Duggan]

Kai.Grossjohann@CS.Uni-Dortmund.DE writes:

> Suppose I had a function which could split some of the incoming
> messages but not all of them.  Thus, the behavior I want is:
> 
> If nnmail-kai-split-smartly returns a group, split the incoming
> message to that group, else process nnmail-split-methods normally.
> 
> I'm also willing to use nnmail-split-fancy, of course, if that helps.
> 
> The documentation for nnmail-split-fancy tells me that it is possible
> to call functions, but it is not clear whether the function is allowed
> to return a don't-know value whereupon the processing of
> nnmail-split-fancy continues.
> 
> Maybe I can just make the function return NIL as a don't-know value?
> The documentation doesn't say, and I don't grok the source.

Well, according to the documentation of nnmail-split-fancy, the
function should return a split.  I guess in the ordinary case, that
would be a string representing the group you wanted to place it into.
But as you correctly guessed, nil is a valid split, which always
fails.  This does not appear to be in the documentation, but appears
in nnmail-split-it:

     ;; nil split
     ((null split)
      nil)

So, as an example, you can have a split like the following:

'(|
  (: my-splitting-function)
  ;; If the above fails...
  (: my-other-splitting-function)
  ;; That fails too?
  (from "foobar" "mail.foobar")
  ;; If it gets here, it must be junk
  junk)

where `my-splitting-function' and `my-other-splitting-function' return
nil if they can't determine a split.

Kudos to Lars, BTW, for creating the wonderful `nnmail-split-fancy'
foo.  It has everything I could want in a splitting engine, and then
some!

-- 
Michael Duggan
(md5i@cs.cmu.edu)
.

Re: How to add new split method?

[Kai.Grossjohann]

Right.  I have now made my function return nil if it hasn't found a
group.  See my posting of a few minutes ago to see what I have done.
kai
-- 
Life is hard and then you die.

Re: How to add new split method?

[Lars Magne Ingebrigtsen]

Michael Welsh Duggan <md5i@cs.cmu.edu> writes:

> Kudos to Lars, BTW, for creating the wonderful `nnmail-split-fancy'
> foo.  It has everything I could want in a splitting engine, and then
> some!

I think so too, which is why I admire Per Abrahamsen so much for
thinking it up and then writing it all by himself.  :-)

-- 
(domestic pets only, the antidote for overdose, milk.)
  larsi@gnus.org * Lars Magne Ingebrigtsen