My Emacs configuration https://git.cjennings.net/dotemacs/atom?h=main 2026-05-25T23:05:45+00:00 2026-05-25T23:05:45+00:00 Craig Jennings c@cjennings.net 2026-05-25T23:05:45+00:00 urn:sha1:9ed2af69be43d889f59ae1ca262af40405c481c5 mouse-trap--build-keymap ran on every major-mode hook and rebuilt the whole keymap (~8 prefixes by ~30 events) from scratch each time, so rapid mode-switching paid that cost over and over. I moved the build into mouse-trap--build-keymap-1 and cache its result in mouse-trap--keymap-cache, keyed on the profile name plus its allowed-categories list. The same profile reuses the cached keymap, and editing a profile's categories changes the key so it rebuilds. Sharing one keymap object across buffers is safe here: the map only binds disallowed events to ignore and is never mutated after it's built. Added mouse-trap--clear-keymap-cache to force a fresh build after editing profiles by hand.