exa: add module

Exa is a 'ls' alternative with more sane colorscheme than lsd on white
backgrounds.

.github/CODEOWNERS

@@ -57,6 +57,8 @@
 
 /modules/programs/emacs.nix                           @rycee
 
+/modules/programs/exa.nix                             @kalhauge
+
 /modules/programs/firefox.nix                         @rycee
 
 /modules/programs/gh.nix                              @Gerschtli

modules/lib/maintainers.nix

@@ -31,6 +31,12 @@
     github = "olmokramer";
     githubId = 3612514;
   };
+  kalhauge = {
+    name = "Christian Gram Kalhauge";
+    email = "kalhauge@users.noreply.github.com";
+    github = "kalhauge";
+    githubId = 1182166;
+  };
   kubukoz = {
     name = "Jakub Kozłowski";
     email = "kubukoz@users.noreply.github.com";

modules/misc/news.nix

@@ -1863,6 +1863,7 @@ in
           lists to polybar-style 'foo-0, foo-1, ...' lists.
         '';
       }
+
       {
         time = "2021-02-25T22:36:43+00:00";
         condition = config.programs.git.enable && any (msmtp: msmtp.enable)
@@ -1873,6 +1874,7 @@ in
           'accounts.email.accounts.<name>.msmtp.enable' is true.
         '';
       }
+
       {
         time = "2021-03-03T22:16:05+00:00";
         message = ''
@@ -1880,6 +1882,7 @@ in
           https://no-color.org/.
         '';
       }
+
       {
         time = "2021-03-29T21:05:50+00:00";
         message = ''
@@ -1887,6 +1890,13 @@ in
           applied after 'programs.dircolors.settings'.
         '';
       }
+
+      {
+        time = "2021-04-11T20:44:54+00:00";
+        message = ''
+          A new module is available: 'programs.exa'.
+        '';
+      }
     ];
   };
 }

modules/modules.nix

@@ -63,6 +63,7 @@ let
     (loadModule ./programs/direnv.nix { })
     (loadModule ./programs/eclipse.nix { })
     (loadModule ./programs/emacs.nix { })
+    (loadModule ./programs/exa.nix { })
     (loadModule ./programs/feh.nix { })
     (loadModule ./programs/firefox.nix { })
     (loadModule ./programs/fish.nix { })

modules/programs/exa.nix

@@ -0,0 +1,36 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.programs.exa;
+
+  aliases = {
+    ls = "${pkgs.exa}/bin/exa";
+    ll = "${pkgs.exa}/bin/exa -l";
+    la = "${pkgs.exa}/bin/exa -a";
+    lt = "${pkgs.exa}/bin/exa --tree";
+    lla = "${pkgs.exa}/bin/exa -la";
+  };
+
+in {
+  meta.maintainers = [ maintainers.kalhauge ];
+
+  options.programs.exa = {
+    enable =
+      mkEnableOption "exa, a modern replacement for <command>ls</command>";
+    enableAliases = mkEnableOption "recommended exa aliases";
+  };
+
+  config = mkIf cfg.enable {
+    home.packages = [ pkgs.exa ];
+
+    programs.bash.shellAliases = mkIf cfg.enableAliases aliases;
+
+    programs.zsh.shellAliases = mkIf cfg.enableAliases aliases;
+
+    programs.fish.shellAliases = mkIf cfg.enableAliases aliases;
+
+  };
+}