From f855cf3f1edc99b6037cb08d7cc68be3b13fffb8 Mon Sep 17 00:00:00 2001
From: derped <derped@ophanim.de>
Date: Thu, 25 Nov 2021 22:15:19 +0100
Subject: [PATCH] emacs: add undo-tree minor mode.

---
 pkgsets/emacs/undo-tree.nix | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 pkgsets/emacs/undo-tree.nix

diff --git a/pkgsets/emacs/undo-tree.nix b/pkgsets/emacs/undo-tree.nix
new file mode 100644
index 0000000..8fd68d2
--- /dev/null
+++ b/pkgsets/emacs/undo-tree.nix
@@ -0,0 +1,16 @@
+{ config, lib, ... }:
+
+with lib;
+
+mkIf (elem "emacs::undo-tree" config.machine.pkgs) {
+  programs.emacs.init.usePackage.undo-tree = {
+    enable = true;
+    hook = [ "(after-init . global-undo-tree-mode)" ];
+    config = ''
+      (setq undo-tree-visualizer-diff 't)
+      (setq undo-tree-auto-save-history 't)
+      (setq undo-tree-enable-undo-in-region 't)
+      (setq undo-tree-history-directory-alist '(("." . "~/.emacs_undo")))
+    '';
+  };
+}