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Notes on vim

It seems that my extended vim experiment has come to an end. I did not mind modal editing and I appreciated the rich language of “text objects” that vim editing is based on. On the other hand, I really disliked most of the editing modes available. Syntax highlighting in vim is fast and, for the most part, reasonable. However, none of the indent scripts impressed me. It is easy enough to write a basic indentation script, but any script like that can be easily fooled. I find occasional bad indentation almost worse than no indentation at all. Fundamentally, vim does not really have support for building parse trees, so accurate indentation is probably not feasible.

Enter yi

I briefly tried to use yi, an emacs-like editor charmingly written in Haskell. To define a syntax mode in yi, you provide a lexer and a parser. This lets yi construct an accurate parse tree (as accurate as the parser you provide), which enables excellent syntax highlighting and indentation. The idea behind yi is exciting, but the current implementation is a bit hard to work with. Most significantly, the incremental parsing framework is not well documented. I wrote a syntax mode for HTML, but I seem to have missed some subtle details required to get acceptable performance from the incremental parser. Documents with more than a few tags quickly peg a CPU and develop enormous space leaks. As far as I can see, my parser and AST look quite a bit like the LaTeX mode included with yi, which performs well on reasonably large documents. Oh well.

Return to emacs

So I am back to emacs. The upshot of the whole vim experiment was that I was motivated to rewrite my emacs configuration to clean it up and improve startup times. It now starts up about as fast as vim: less than half a second. I also fixed a few things in various modes I used that really annoyed me before, but that I was never motivated to deal with properly.

Startup time

My old emacs configuration could best be described as “cobbled together”. I had snippets taken from the emacs wiki and all sorts of packages just dumped in ~/.emacs.d. I imagine not a few were loaded or required in unfortunate places. Now that all of my machines are running emacs 24, I switched to using package.el to manage my emacs packages. I just have a list of packages I use and a check on startup that installs any that are not currently installed. This seems to do all of the correct autoloading and has no observable impact on startup time. The only package I require now at the start of my init.el is package.el to manage my required packages. The few other functions I directly reference from elisp code are autoloaded on demand.

As a side note, I am using MELPA instead of marmalade, largely because the former loaded faster and was more responsive when I was looking through the package lists.

Keybindings

The biggest annoyance with my emacs configuration before my vim experiment was that, occasionally, I would fat finger C-xC-s (save buffer) and hit some key combination that I never could figure out. Unfortunately, that key combination consistently and helpfully locked up my emacs frame. I always had trouble reviving it after that and usually just killed it and restarted emacs. It was infuriating. I finally tracked it down: I was hitting C-xC-z, which is suspend-frame. First, I have never wanted to do that. Second, the behavior of suspend-frame is somewhat unusual with a tiling window manager like xmonad. Normally, suspend-frame minimizes the frame. xmonad does not really have a concept of “minimize”, but the frame stops accepting input (since it expects that it is minimized). Under xmonad, the frame is still visible and it just appears to have locked up. Needless to say, this was a bit tough to google. It also would not have been a problem under a normal window manager, since the effect of the key binding would have been obvious. The solution was simple: disable the offending keybinding:

(global-unset-key "\C-x\C-z")

auctex changes

auctex is an excellent LaTeX editing environment. There has always been just one feature that annoyed me: section and subsection headings are displayed in a proportional (and large) font face by default. Minor, but annoying. I used to use M-x customize to change all of the fonts manually, but that was obnoxious. The correct incantation is:

(setq font-latex-fontify-script nil)
(setq font-latex-fontify-sectioning 'color)
(add-hook 'LaTeX-mode-hook
          #'(lambda ()
              (custom-set-faces '(font-latex-slide-title-face ((t (:inherit font-lock-type-face)))))
              (font-latex-update-sectioning-faces)))

I think I found that somewhere on stackexchange.

Misc changes

I finally read up on the difference between setq and setq-default, so I modified my configuration to use the correct calls where necessary. For the record, setq-default sets a global default for buffer-local variables that can be overridden locally in each buffer. setq sets global variables.