#+title: Oni Machine Interface
#+subtitle: My Literate Machine Configuration
#+options: num:nil

This is my latest attempt at a literate configuration.

#+begin_note
This is in the very early stages of an attempt to do this. And usually I get frustrated and give up quite early on. I'll try and get small bits and pieces in here one at a time.
#+end_note

Here is the command that converts this file into my home configuration. This calls [[file:../guix.org][Guix]] shell with /just/ the =emacs-next= package installed and runs [[file:../emacs.org][Emacs]] to tangle this file. When tangling is done it runs guix home to configure my environment.

#+begin_note
For the moment this doesn't do ~guix home reconfigure~ but ~guix home build~ instead. I'm still getting this up to the point where I can actually use it.
#+end_note

#+begin_src sh :results silent
  guix shell --pure emacs-next -- emacs \
       -quick -batch \
       -load ob-tangle \
       -visit rincewind.org \
       -funcall org-babel-tangle
  guix home build rincewind.scm
#+end_src

* Environment

This is a random assortment of environment variables that I like to have defined for various reasons.

The =LESS= environment variable specifies the default command-line arguments to pass in to =less= whenever it is run. I've gotten quite used to these:

#+ATTR_HTML: :class short-dl
- =F= :: Causes =less= to exit right away when there is less than one screen of text to display.
- =X= :: Prevents the screen from being cleared away when =less= exits (it does more, but this is why I use it)
- =R= :: Displays ANSI color escape sequences to be rendered as normal, instead of as readable characters. In other words it lets =less= display colored text instead of displaying escape sequences.
- =S= :: Truncates long lines instead of wrapping them. Makes it easier for me to read.
- =i= :: This causes any searches using =/= to become case-insensitive so that the search term “done” will match “done”, “Done”, “DONE”, and any other combination of upper- and lowercase letters.

#+begin_src scheme :noweb-ref environment-variables
  ("LESS" . "FXRSi")
#+end_src

I use the =MY_GUIX_CONFIGURED= just as an indication that [[file:../guix.org][Guix]] home actually configured my user profile. It's not actually necessary for anything.

#+begin_src scheme :noweb-ref environment-variables
  ("MY_GUIX_CONFIGURED" . "1")
#+end_src

This opts out of sending any telemetry to Microsoft whenever I play around with any .Net things.

#+begin_src scheme :noweb-ref environment-variables
  ("DOTNET_CLI_TELEMETRY_OPTOUT" . "1")
#+end_src

Turn on dark-mode for Calibre. I prefer dark mode everywhere.

#+begin_src scheme :noweb-ref environment-variables
  ("CALIBRE_USE_DARK_PALETTE" . "1")
#+end_src

Because I use [[file:../guix.org][Guix]] on top of another distribution, this variable needs to be set in order for locales to work properly for both package installed through Guix and ones installed by the host distribution.

#+begin_src scheme :noweb-ref environment-variables
  ("GUIX_LOCPATH" . "$HOME/.guix-home/profile/lib/locale")
#+end_src

Again because I use Guix on top of another distribution this variable ensures that the things I have stored away in my usual data directory get included, not just the ones Guix defines.

#+begin_src scheme :noweb-ref environment-variables
  ("XDG_DATA_DIRS"
   . "${XDG_DATA_DIRS}${XDG_DATA_DIRS:+:}/usr/local/share:/usr/share")
#+end_src

I was working with =git= recently, splitting some utilities out into their own repository from a bigger repository using =filter-branch=. Apparently =filter-branch= has been deprecated because it's easy to make mistakes and there's better alternatives now. But =filter-branch= is what I know and my needs are simple, so I disable that warning.

#+begin_src scheme :noweb-ref environment-variables
  ("FILTER_BRANCH_SQUELCH_WARNING" . "1")
#+end_src

Putting it all together to define the service for my home configuration.

#+begin_src scheme :noweb yes :noweb-ref services
  (define oni-environment-service
    (simple-service
     'home-environment-service
     home-environment-variables-service-type
     '(
       <<environment-variables>>)))
#+end_src

* Home

This brings it all together. The =<<services>>= is where all the services defined throughout this document are placed, and the last few lines return my home environment.

#+begin_src scheme :tangle rincewind.scm :noweb tangle
  (use-modules
   (gnu services)
   (gnu home services))

  <<services>>

  (home-environment
   (services
    (list
     oni-environment-service)))
#+end_src

* Changelog

- [2022-11-16 Wed] :: Added a code block that tries to tangle this file and then build the result. And made the output an actual home environment.