aboutsummaryrefslogtreecommitdiff
path: root/infra/libkookie/nixpkgs/doc/builders/packages/emacs.section.md
diff options
context:
space:
mode:
Diffstat (limited to 'infra/libkookie/nixpkgs/doc/builders/packages/emacs.section.md')
-rw-r--r--infra/libkookie/nixpkgs/doc/builders/packages/emacs.section.md119
1 files changed, 119 insertions, 0 deletions
diff --git a/infra/libkookie/nixpkgs/doc/builders/packages/emacs.section.md b/infra/libkookie/nixpkgs/doc/builders/packages/emacs.section.md
new file mode 100644
index 000000000000..e9b89d086d68
--- /dev/null
+++ b/infra/libkookie/nixpkgs/doc/builders/packages/emacs.section.md
@@ -0,0 +1,119 @@
+# Emacs {#sec-emacs}
+
+## Configuring Emacs {#sec-emacs-config}
+
+The Emacs package comes with some extra helpers to make it easier to configure. `emacsWithPackages` allows you to manage packages from ELPA. This means that you will not have to install that packages from within Emacs. For instance, if you wanted to use `company` `counsel`, `flycheck`, `ivy`, `magit`, `projectile`, and `use-package` you could use this as a `~/.config/nixpkgs/config.nix` override:
+
+```nix
+{
+ packageOverrides = pkgs: with pkgs; {
+ myEmacs = emacsWithPackages (epkgs: (with epkgs.melpaStablePackages; [
+ company
+ counsel
+ flycheck
+ ivy
+ magit
+ projectile
+ use-package
+ ]));
+ }
+}
+```
+
+You can install it like any other packages via `nix-env -iA myEmacs`. However, this will only install those packages. It will not `configure` them for us. To do this, we need to provide a configuration file. Luckily, it is possible to do this from within Nix! By modifying the above example, we can make Emacs load a custom config file. The key is to create a package that provide a `default.el` file in `/share/emacs/site-start/`. Emacs knows to load this file automatically when it starts.
+
+```nix
+{
+ packageOverrides = pkgs: with pkgs; rec {
+ myEmacsConfig = writeText "default.el" ''
+ ;; initialize package
+
+ (require 'package)
+ (package-initialize 'noactivate)
+ (eval-when-compile
+ (require 'use-package))
+
+ ;; load some packages
+
+ (use-package company
+ :bind ("<C-tab>" . company-complete)
+ :diminish company-mode
+ :commands (company-mode global-company-mode)
+ :defer 1
+ :config
+ (global-company-mode))
+
+ (use-package counsel
+ :commands (counsel-descbinds)
+ :bind (([remap execute-extended-command] . counsel-M-x)
+ ("C-x C-f" . counsel-find-file)
+ ("C-c g" . counsel-git)
+ ("C-c j" . counsel-git-grep)
+ ("C-c k" . counsel-ag)
+ ("C-x l" . counsel-locate)
+ ("M-y" . counsel-yank-pop)))
+
+ (use-package flycheck
+ :defer 2
+ :config (global-flycheck-mode))
+
+ (use-package ivy
+ :defer 1
+ :bind (("C-c C-r" . ivy-resume)
+ ("C-x C-b" . ivy-switch-buffer)
+ :map ivy-minibuffer-map
+ ("C-j" . ivy-call))
+ :diminish ivy-mode
+ :commands ivy-mode
+ :config
+ (ivy-mode 1))
+
+ (use-package magit
+ :defer
+ :if (executable-find "git")
+ :bind (("C-x g" . magit-status)
+ ("C-x G" . magit-dispatch-popup))
+ :init
+ (setq magit-completing-read-function 'ivy-completing-read))
+
+ (use-package projectile
+ :commands projectile-mode
+ :bind-keymap ("C-c p" . projectile-command-map)
+ :defer 5
+ :config
+ (projectile-global-mode))
+ '';
+
+ myEmacs = emacsWithPackages (epkgs: (with epkgs.melpaStablePackages; [
+ (runCommand "default.el" {} ''
+ mkdir -p $out/share/emacs/site-lisp
+ cp ${myEmacsConfig} $out/share/emacs/site-lisp/default.el
+ '')
+ company
+ counsel
+ flycheck
+ ivy
+ magit
+ projectile
+ use-package
+ ]));
+ };
+}
+```
+
+This provides a fairly full Emacs start file. It will load in addition to the user's presonal config. You can always disable it by passing `-q` to the Emacs command.
+
+Sometimes `emacsWithPackages` is not enough, as this package set has some priorities imposed on packages (with the lowest priority assigned to Melpa Unstable, and the highest for packages manually defined in `pkgs/top-level/emacs-packages.nix`). But you can't control this priorities when some package is installed as a dependency. You can override it on per-package-basis, providing all the required dependencies manually - but it's tedious and there is always a possibility that an unwanted dependency will sneak in through some other package. To completely override such a package you can use `overrideScope'`.
+
+```nix
+overrides = self: super: rec {
+ haskell-mode = self.melpaPackages.haskell-mode;
+ ...
+};
+((emacsPackagesGen emacs).overrideScope' overrides).emacsWithPackages
+ (p: with p; [
+ # here both these package will use haskell-mode of our own choice
+ ghc-mod
+ dante
+ ])
+```