my-site-start

This is a simple Elisp library to help you keep your init.el clean and modular. In brief,

• Adding new libraries is simple -- just create or symlink a new directory in your site-start.d tree. No need to explicitly update your load-path etc.

• Detailed yet uncomplicated control over what gets loaded at start-up, what gets loaded only when needed, and what gets loaded only when Emacs is started in interactive mode -- a simple and straightforward naming scheme decides what to load when.

You can start using it right away, and migrate your existing configuration to a more modular layout by and by.

Introduction

The purpose of my-site-start is to simplify maintenance of user libraries. Instead of indefinitely tweaking your .emacs, just create a site-start.d directory and add symlinks to the libraries you want to load into Emacs.

Of course, my-site-start itself needs to be configured in the old-fashioned style;

(autoload 'my-site-start "path/to/my-site-start" nil t)
(my-site-start "~/.emacs.d/site-start.d/")

This will load all files matching my-site-start-file-name-regex in .emacs.d/site-start.d/, including any symlinks and subdirectories.

The default policy is to recursively add all directories in the site-start.d tree to the load-path, and from within these, to load all files matching [0-9][0-9]*.elc?, those with a numeric prefix below 100 immediately, and others deferred.

Directories are traversed depth-first and added to load-path in the order they were found. (This is not currently configurable.)

For example, assume the following directory structure:

~/
  .emacs                <- legacy; modern default is .emacs.d/init.el
  .emacs.d/
    fnord/              <- not in site-start.d, so ignored
      10foo.el          <- just to illustrate that only site-start.d ...
      bar.el            <- ... is traversed by default
    site-start.d/
      01globals.el
      50autoloads.el
      1000interactive.el
      darcsum/          <- symlink to ~/hack/darcsum/local-trunk
        50darcsum.el
        darcsum.el
        changelog
      bibtex.el         <- patched version to override system bibtex.el
      my-local-prefs/   <- symlink to ~/hack/my-local-prefs/production
        00globals.el
        50autoloads.el
        900cperl.el
        950rst.el

The following directories will be added to the front of load-path:

 ~/.emacs.d/site-start.d
 ~/.emacs.d/site-start.d/darcsum
 ~/.emacs.d/site-start.d/my-local-prefs

(The last one is not really useful to have on load-path, because all the files in that directory will be loaded by my-site-start with an explicit path, but this is of course by and large harmless.)

The following files will be loaded immediately, in this order:

 ~/.emacs.d/site-start.d/my-local-prefs/00globals.el
 ~/.emacs.d/site-start.d/01globals.el
 ~/.emacs.d/site-start.d/50autoloads.el
 ~/.emacs.d/site-start.d/my-local-prefs/50autoloads.el
 ~/.emacs.d/site-start.d/darcsum/50darcsum.el

(By no coincidence, this naming convention copies the one used by Debian in /etc/emacs/site-start.d -- if you have a local, private copy of a package with Debian startup files, you can use it directly, without modification.)

The following files will be loaded deferred, in this order:

 ~/.emacs.d/site-start.d/my-local-prefs/900cperl.el
 ~/.emacs.d/site-start.d/my-local-prefs/950rst.el
 ~/.emacs.d/site-start.d/1000interactive.el

Deferred loading happens only when Emacs is running in interactive mode, when all other initialization has completed. It is thus a useful facility for loading some user-interface functionality only when you need it (and avoid the overhead when running Emacs in batch mode, i.e. when compiling packages etc) and also offers a convenient place for Lisp snippets you only want to load when everything else is done.

This is probably how you want to run my-site-start -- just set it up and forget it, except when you want to add a new package, and instead forget the tedium of polluting your Emacs startup file with yet another trivial load-path tweak and keybindings you only use interactively.

However, see the documentation strings in the code for more flexible and/or more restricted usage scenarios.

There is a helper script add-to-site-start which you might want to symlink to your $HOME/bin for conveniently adding new directories to site-start.d as symlinks.

What Now?

Fundamentally, my-site-start is just a simple but versatile platform for turning a monolithic Emacs configuration into a modular one. The process is straightforward and can probably be completed in a few hours, but if you don't want to go all-in, just start using my-site-start and amortize on the modularization work whenever you need to tweak your Emacs configuration anyway.

For example, assuming you have a section dedicated to TeX in your .emacs.d/init.el, you might start by moving the entire section to a new file my-tex.el in site-start.d -- it will be added to your load-path, so now you could do something simple like

;;; 500my-tex.el -- load TeX stuff when visiting a .tex file

(eval-after-load "auctex" '(load-library "my-tex"))

;;; 500my-tex.el ends here

and instantly remove all the interactive TeX helpers out of your way when you are not using Emacs for TeX work.

Proceed with other sections of your Emacs startup file when you feel the need or have the time -- fairly soon, you might find yourself with an Emacs startup file which only contains the my-site-start bootstrap code.

See Also

This repository used to live at http://porkmail.org/elisp but the old location is no longer kept up to date, and will disappear soon.

For the competition, see http://www.emacswiki.org/emacs/DotEmacsModular

License

GPL v2.