Initial emacs module

home/modules/emacs.nix

@@ -0,0 +1,75 @@
+# https://nixos.org/manual/nixos/stable/index.html#sec-writing-modules
+
+# This is a function with arguments
+{ config, lib, pkgs, ... }:
+
+# We add stuff from lib to our namespace (mkOption...)
+with lib;
+
+let
+  # This is the current state of the option that this module defines
+  # We use it to determine if the config should be changed below
+  cfg = config.modules.emacs;
+in {
+  imports = [];
+
+  # Options is a vector of options this module defines
+  # This module defines only the "emacs" option and suboptions "enable" and "doom"
+  options.modules.emacs = {
+    enable = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Enable the GNU Emacs editor";
+    };
+
+    useDoom = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Use the Doom Emacs framework";
+    };
+  };
+
+  # Config is the merged set of all module configurations
+  # Here we define what happens to the config if the module is active (but only if the module is active)
+  # Since this module is for HomeManager, config is not the system config
+  config = mkIf cfg.enable {
+    # What home packages should be enabled
+    home.packages = [
+      binutils
+      zstd
+      (ripgrep.override { withPCRE2 = true; })
+      fd
+      # libgccjit
+      sqlite
+      python310Packages.pygments
+      inkscape
+      graphviz
+      gnuplot
+      pandoc
+      nixfmt
+      shellcheck
+      maim
+    ];
+
+    programs.emacs = {
+      package = pkgs.emacsPgtkNativeComp;
+      enable = true;
+    };
+
+    home.sessionPath = [
+      "/home/${home.username}/.emacs.d/bin"
+    ];
+
+    # TODO:
+    # fonts.fonts = [ pkgs.emacs-all-the-icons-fonts ];
+
+    # If doom is enabled we want to clone the framework
+    system.userActivationScripts = mkIf cfg.useDoom {
+      installDoomEmacs = ''
+        if [ ! -d "${home.homeDirectory}/.emacs.d" ]; then
+           git clone --depth=1 --single-branch "https://github.com/doomemacs/doomemacs" "${home.homeDirectory}/.emacs.d"
+        fi
+      '';
+    };
+  };
+}