nixpkgs/pkgs/applications/editors/emacs/site-start.el
Moritz Ulrich 7cfdb2b1b5
emacs: Search subdirectories of site-lisp in NIX_PROFILES
This adds subdirectories of `share/emacs/site-lisp/` in every path in
`NIX_PROFILES` to `load-path` to allow loading of more complex
libraries like `mu4e`.

Fixes #33412
2018-01-05 10:50:18 +01:00

57 lines
2.5 KiB
EmacsLisp

(defun nix--profile-paths ()
"Returns a list of all paths in the NIX_PROFILES environment
variable, ordered from more-specific (the user profile) to the
least specific (the system profile)"
(reverse (split-string (or (getenv "NIX_PROFILES") ""))))
;;; Extend `load-path' to search for elisp files in subdirectories of
;;; all folders in `NIX_PROFILES'. Also search for one level of
;;; subdirectories in these directories to handle multi-file libraries
;;; like `mu4e'.'
(require 'seq)
(let* ((subdirectory-sites (lambda (site-lisp)
(when (file-exists-p site-lisp)
(seq-filter (lambda (f) (file-directory-p (file-truename f)))
;; Returns all files in `site-lisp', excluding `.' and `..'
(directory-files site-lisp 'full "^\\([^.]\\|\\.[^.]\\|\\.\\..\\)")))))
(paths (apply #'append
(mapcar (lambda (profile-dir)
(let ((site-lisp (concat profile-dir "/share/emacs/site-lisp/")))
(cons site-lisp (funcall subdirectory-sites site-lisp))))
(nix--profile-paths)))))
(setq load-path (append paths load-path)))
;;; Make `woman' find the man pages
(eval-after-load 'woman
'(setq woman-manpath
(append (mapcar (lambda (x) (concat x "/share/man/"))
(nix--profile-paths))
woman-manpath)))
;;; Make tramp work for remote NixOS machines
(eval-after-load 'tramp
;; TODO: We should also add the other `NIX_PROFILES' to this path.
;; However, these are user-specific, so we would need to discover
;; them dynamically after connecting via `tramp'
'(add-to-list 'tramp-remote-path "/run/current-system/sw/bin"))
;;; C source directory
;;;
;;; Computes the location of the C source directory from the path of
;;; the current file:
;;; from: /nix/store/<hash>-emacs-<version>/share/emacs/site-lisp/site-start.el
;;; to: /nix/store/<hash>-emacs-<version>/share/emacs/<version>/src/
(let ((emacs
(file-name-directory ; .../emacs/
(directory-file-name ; .../emacs/site-lisp
(file-name-directory load-file-name)))) ; .../emacs/site-lisp/
(version
(file-name-as-directory
(concat
(number-to-string emacs-major-version)
"."
(number-to-string emacs-minor-version))))
(src (file-name-as-directory "src")))
(setq find-function-C-source-directory (concat emacs version src)))