Re: Tool for writing thin wrappers for changing existing elisp configurations

[Andreas Röhler]

Am 07.04.2014 20:40, schrieb Andrey Tykhonov:
> Hi List,
>
> is there any way to change configuration files by means of elisp functions?
> Which of them may help?
>
> For example, there are such lines in the ~/.gnus.el (but please note that
> that question is not about Gnus):
>
> #+begin_src elisp
> (setq nnmail-split-fancy
>        '(|
>          (: nnmail-split-fancy-with-parent )
>          (any "help-gnu-emacs@gnu\\.org" "help-gnu-emacs")
>          (any "emacs-devel@gnu\\.org" "emacs-devel")
>          "mail.misc"))
> #+end_src
>
> I would like to write a thin wrapper, interactive elisp function, which
> will be able to append new entry to the `nnmail-split-fancy'.
>
> When I will call that function (M-x add-nnmail-split-fancy-entry) then I'll
> be prompted for email address and imap folder (let 'any' will be
> hard-coded). Thus such command execution:
>
> M-x add-nnmail-split-fancy-entry RET emacs-orgmode@gnu.org RET
> emacs-orgmode RET
>
> will change configuration of the mentioned lines to the following:
>
> #+begin_src elisp
> (setq nnmail-split-fancy
>        '(|
>          (: nnmail-split-fancy-with-parent )
>          (any "help-gnu-emacs@gnu\\.org" "help-gnu-emacs")
>          (any "emacs-devel@gnu\\.org" "emacs-devel")
>          (any "emacs-orgmode@gnu\\.org" "emacs-orgmode")
>          "mail.misc"))
> #+end_src
>
> Yes, of course, I can just open ~/.gnus.el and add such entry. And of
> course I can change via M-x customize-variable RET nnmail-split-fancy RET.
>
> But this question is not about *how* to change existing elisp configuration
> but about a tool. I wonder: is there any elisp tool (package, functions
> etc) which allows to write such a thin wrapper (elisp program); wrapper
> which allows to change source of existing elisp program (configuration)?
>
> How would you implement such a wrapper? Any suggestions? Would you suggest
> to investigate how does work `customize-variable'? What else?
>
>
>
> Andrey

You could have a batch file calling Emacs to change existing file(s) as you can 
change this files calling other programs.
Also loading a certain init file might be an option, keeping several init-files.

Emacs init files are in Emacs lisp as others. Don't see anything special so far 
when changing it.

HTH,

Andreas