Re: axiom mode

[martin rudalics <rudalics@gmx.at>]

 > I meant, desired behaviour should be:
 >
 > M-x axiom switches to the buffer *axiom*, if it exists and if it is an "axiom
 >           buffer".  (I guess that should be a buffer in axiom-mode, with a
 >           running axiom process.)
 >
 >           If there is no such buffer, it creates a new buffer and a new axiom
 >           process.

... and puts it in `axiom-mode'.  FWIW that's what your code does at the
moment.

 >           (add-hook 'axiom-mode-hook (lambda () (rename-uniquely))) should
 >           rename the buffer.  I do not know what else one could use
 >           shell-mode-hook (and therefore axiom-mode-hook) for.

Why do you want to rename the buffer?

 > Should I make all variables local?

The only variable I can think of at the moment is `axiom-process'.

 > I guess, variables introduced with defvar
 > are intended to be customizable by the user

... `defcustom' serves that purpose ...

 > and are global to all buffers in
 > axiom mode?

A priori a symbol defined as a variable doesn't relate to buffers hence
it "is global".

 > Other variables, global to each individual buffer are introduced
 > by make-local-variable?

You should defvar them first and make them buffer-local either by using
`make-variable-buffer-local' or, better, `make-local-variable'.  A
typical idiom in this context is

(set (make-local-variable 'foo) value)

which makes foo buffer-local and assigns it value.

If you really need multiple axiom processes - so far you didn't tell me
_why_ you need them - you would make `axiom-process' local in the buffer
where you create the process and set it to the process object returned
by comint.  Otherwise, I see no need to change anything here.