Re: Creating an Emacs Home Configuration Service

[jbranso@dismail.de]

October 17, 2022 2:38 AM, "Zain Jabbar" <zaijab2000@gmail.com> wrote:

> Aloha Guix Development Team,
> 
> Running =guix home search emacs= returns nothing. I also could not find an email using =C-u M-x
> debbugs-gnu= about an Emacs configuration service.
> 
> This is my first email to this mailing address. Please give me pointers on formatting and further
> improvements.

I think you sent an html email.  Generally you want to send plain text emails.  :)
 
> I have attempted to make an =emacs-home-service-type= so that it is possible to configure Emacs
> using Guix home. This code is extremely preliminary hence I don't even think it is worth sending as
> a patch. Also I have never worked on a multi person Git project before and do not know how to solve
> the keyring error I get when using guix pull. I will outline what my code does and what features I
> would like to add.
> 
> #+BEGIN_SRC scheme
> (define* (emacs-configuration-service name #:key (init '()) (early-init '()) (emacs-packages '()))
> (service-type (name (symbol-append 'emacs- name '-configuration))
> (extensions
> (list (service-extension
> home-profile-service-type
> (lambda (config) emacs-packages))
> (service-extension
> home-files-service-type
> (lambda (config)
> (list
> `(,(string-append
> ".config/emacs/services/" (symbol->string name) ".el")
> ,(scheme-file (string-append (symbol->string name) ".el")
> init #:splice? #t))
> `(,(string-append
> ".config/emacs/early-services/" (symbol->string name) ".el")
> ,(scheme-file (string-append "early-" (symbol->string name) ".el")
> early-init #:splice? #t)))))))
> (default-value #f)
> (description "Configures Emacs init.el")))
> 
> (define-public emacs-init-service-type
> (service-type (name 'home-emacs)
> (extensions
> (list (service-extension
> home-profile-service-type
> (lambda (config) (list emacs-next)))
> (service-extension
> home-files-service-type
> (lambda (config)
> (list
> `(".config/emacs/early-init.el"
> ,(scheme-file
> "early-init.el"
> '((mapc
> 'load (file-expand-wildcards
> "~/.config/emacs/early-services/*.el")))
> #:splice? #t))
> `(".config/emacs/init.el"
> ,(scheme-file
> "init.el"
> '((mapc
> 'load (file-expand-wildcards
> "~/.config/emacs/services/*.el")))
> #:splice? #t)))))))
> (default-value #f)
> (description "Configures Emacs init.el")))
> #+END_SRC
> 
> I define a general configuration service generator which takes in four things:
> 1. The =name= of the service
> 2. The configuration to be ran in =init.el=
> 3. The configuration to be ran in =early-init.el=
> 4. The packages in Guix to be added to the =home-profile=.
> 
> After giving the =name=, =packages=, and =config.el= files we get a new service type that we can
> add to our home declaration. This service will then add a file in
> =~/.config/emacs/services/emacs-{NAME}-configuration.el=. I then have another service that places
> an =init.el= which loads everything in the service directory.
> 
> If we want to install and configure =evil-mode= using this =home-service= we may define the
> following somewhere.
> 
> #+BEGIN_SRC scheme
> (define-public emacs-evil-service-type
> (emacs-configuration-service
> 'evil #:emacs-packages (list emacs-evil)
> #:init '((evil-mode 1))))
> #+END_SRC
> 
> Within our =home-environment= we may add the service using:
> 
> #+BEGIN_SRC scheme
> (home-environment
> ;; ...Things in the home-environment...
> (services
> (list
> ;; ...Other Services...
> (service emacs-evil-service-type))))
> #+END_SRC
> 
> There are some missing features I want to add.
> 
> 1. Have the =home-emacs-*-service-type= service-types add to the =init.el= directly rather than
> within a folder to be loaded. I couldn't add two files with the same name to the store. So I have
> emacs-evil.el in the store to be placed separately later rather than appending to the existing
> init.el file.
> 
> 2. Have Emacs update whenever the =home-environment= is updated. Meaning, if I did not add
> =(service emacs-evil-service-type)= in my =home-environment= then obviously =M-x evil-mode= should
> not work. But after adding the service then I want =M-x evil-mode= to work without having to
> restart Emacs. I do not understand the Emacs loading system on Guix well enough to know why it does
> not work. Skipping all of the =home-service= stuff, running =guix install emacs-evil-mode= then
> =(guix-emacs-autoload-packages)= does not let emacs know that =evil-mode= is installed. I would
> need to close Emacs and start Emacs again for Emacs to know about =evil-mode= being installed.
> 
> 3. Use configurations somehow. I have completely neglected this feature in my system. I do not know
> what would be useful there.

I believe that you are referring to using scheme records to configure the emacs service.  :)

I would recommend using (define-configuration ...) procedure.

(There is a define-record-type* as well, but I think the consensus is that 
define-configuration* is a little easier to use.  Does better error handling
and can help you generate documentation from the code).

You can find examples of that here:

https://git.savannah.gnu.org/cgit/guix.git/tree/gnu/services/mail.scm

> 
> --
> Thank you,
> Zain Jabbar