Posts from April 08, 2026

I wondered yesterday:

...those question headers are displaying differently, with the background colour no longer spanning the width of the window. I'd like to understand why.

Turns out it was pretty straightforward:

diff --git a/quiz.el b/quiz.el
index 2dbe45d..c1ba255 100644
--- a/quiz.el
+++ b/quiz.el
@@ -40,7 +40,8 @@
 (defface quiz-question-number-face
   '((t :height 1.3
        :background "black"
-       :foreground "white"))
+       :foreground "white"
+       :extend t))
   "Face for the question number."
   :group 'quiz)

and so v1.7 has happened.

It looks like, perhaps, at some point in the past, :extend was t by default, but it no longer is? Either way, explicitly setting it to t has done the trick.

Today's Emacs Lisp package tidy-up is of a package I first wrote a couple of employers ago. While working on code I often found myself viewing FASTA files in an Emacs buffer and so I thought it would be fun to use this as a reason to knock up a simple mode for highlighting them.

fasta.el was the result.

While I doubt it was or is of much use to others, it helped me better understand simple font-locking in Emacs Lisp, and also made some buffers look a little less boring when I was messing with test data.

As for this update: it's the usual stuff of cleaning up deprecated uses of setf, mostly.

If bioinformatics-related Emacs Lisp code written by a non-bioinformatician is your thing, you might also find 2bit.el of interest too. Much like fasta.el it too probably doesn't have a practical use, but it sure was fun to write and taught me a few things along the way; it also sort of goes hand-in-hand with fasta.el too.