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Moving around point (using the cursor keys) in Xah’s unicode.txt in fundamental-mode is noticeably slower than in an ordinary text file. Are the many non-ASCII characters the issue? Anything else?

About: GNU Emacs 25.2.1 (x86_64-w64-mingw32) of 2017-04-24 started with option -Q

feklee
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  • I can see all characters and I do not have slow downs, neither in `text-mode` nor `fundamental-mode`. I'm using 24.5 GTK with Linux. How are you moving point, by keyboard input? – jue Jun 13 '17 at 12:50
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    https://github.com/purcell/emacs.d/issues/273 see if this is relevant. – wvxvw Jun 13 '17 at 12:57
  • I see no problem on OSX either using Emacs 25.2.1. – lawlist Jun 13 '17 at 16:09

1 Answers1

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Reading the GitHub discussion thread linked in @wvxvw’s comment, I discovered the variable inhibit-compacting-font-caches. Setting it to non-nil solves the issue:

(setq inhibit-compacting-font-caches t)

Now navigating point is fast. According to the variable’s documentation, inhibiting compacting font caches comes at the expense of more memory usage, which is fine for me.

See also bug 27350 filed by @Drew.

feklee
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