A GNU Emacs experience throught NixOS

2025-02-26

I have always used

as a code editor. I've already tried using

, but only for testing purposes and not with the aim of changing text editors.

This time, I decided to use a

code editor in the terminal, the aim being to replace

indefinitely. This blog post is actually written with it.

It is none other than

. For the convenience of writing and reading this post, I'll simply write “Emacs” to designate the

project.

Why

Why did I leave

and decide to switch to

?

Leaving VSCode

Because it's a RAM-hungry graphics application. You shouldn't need that much memory to edit text and connect to an LSP server. We're talking about 1.2 GB compared with around 200 GB for the same project.

Also, I don't want all the additional features offered, such as file name and text parsing, to suggest that I download extensions. I simply need a simple, functional text-editing application. I don't enjoy using

anymore, so it's time to say goodbye.

Choosing Emacs

Of all the text editors out there, I chose

. It's actually much more than that. In the words of

.

It is a programmable platform where text editing is one of the main points of interaction.

Indeed, I see

more as an operating system than as a text editor. The possibilities for configuring and extending it are virtually infinite.

Also, I find it an excellent UNIX citizen. The default keystroke sequences correspond to those used in other applications in the terminal. ar example, the moves in a Linux manual read with the man command or those in the results of fzf.

Another reason was to be able to modify any behavior, to be able to have an application that corresponds precisely to what you want to have.

Learning

So I installed

version 29.4 and started learning how to use it properly.

Mastering Emacs, Mickey Pertersen

This book explained the important concepts of the application and gave me a solid foundation for getting started with

. Certain chapters, such as “The Theory of Movement” and “The Theory of Editing”, explained to me the best practices for efficient and rapid buffering.

I highly recommend this book for anyone wishing to start learning

.

Emacs Lisp Intro

I've also read the “Emacs Lisp Intro” written in

as a manual. Since most of the code is written in

Lisp, it's essential to understand the language, or at least know how to read it, in order to configure the editor.

For example, I needed to write some to display line numbers at the start of

mode, and to hide them at the end of minor mode execution.

Environment

As I said earlier,

is a platform with a whole host of features. This makes it all the more tempting to leave this environment, which offers numerous possibilities, such as organizing a diary, compiling a project, accessing a shell or terminal emulator, making a presentation, taking notes, managing

modes and packages, etc.

Staying in the same environment made me more productive and faster. For computer development,

can be configured like an IDE, precisely and fully controlled.

One last very important thing to know is that any piece of

is documented, meaning that whatever I do or try to do, I can find documentation.

is its own documentation.

Configuration

Via NixOS

Concerning the tool configuration, being on

, I decided to use the

module provided by the home-manager. To remain consistent with my current configuration, which is highly modularized, each

package has its own Nix module.

Here's what the file structure looks like.

modules/home/editors/emacs
├── default.nix
└── packages
    ├── auto-save
    │   └── default.nix
    ├── dashboard
    │   └── default.nix
    ├── dired
    │   └── default.nix
    ├── doom-modeline
    │   └── default.nix
    ├── ivy
    │   └── default.nix
    ├── lsp-mode
    │   ├── bash-language-server
    │   │   └── default.nix
    │   ├── default.nix
    │   ├── dockerfile
    │   │   └── default.nix
    │   ├── gopls
    │   │   └── default.nix
...

These modules contain the dependencies, i.e. the

packages and the

Lisp configuration.

Here's an example with the

package.

{
  config,
  lib,
  namespace,
  ...
}:
let
  inherit (lib) mkIf;
  inherit (lib.${namespace}) mkBoolOpt;

  cfg = config.${namespace}.editors.emacs.packages.org-superstar;
in
{
  options.${namespace}.editors.emacs.packages.org-superstar = {
    enable = mkBoolOpt false "Whether or not to enable the emacs org-superstar package.";
  };

  config = mkIf cfg.enable {
    programs.emacs = {
      extraPackages = (epkgs: [ epkgs.org-superstar ]);
      extraConfig = ''
        (use-package org-superstar
          :ensure t
          :after org
          :hook (org-mode . org-superstar-mode)
          :custom
            (org-superstar-remove-leading-stars t)
            (org-superstar-headline-bullets-list '("⁖" "✿" "▷" "✸")))
      '';
    };
  };
}

Notes taking on Emacs

has a major mode called

, which modifies

behavior to create an environment suited to writing data in org format. It integrates perfectly with

other features and keeps me in the application.

I used to take my notes with Obsidian. I refactored all my notes and converted them to

format.

Conclusion

From now on, I intend to use

as my main text editor, as well as for note-taking.