Install develock-el by entering the following commands in the terminal:
sudo apt update sudo apt install develock-el
Description:
additional font-lock keywords for the developers on Emacs
Develock is a minor mode which provides the ability to make font- lock highlight leading and trailing whitespace, long lines and oddities in the file buffer for Lisp modes, ChangeLog mode, Texinfo mode, C modes, OCaml modes, Coq mode, LaTeX mode, Java mode, Jde-mode, CPerl mode, Perl mode, HTML modes and some Mail modes.
Homepage: http://www.jpl.org/elips/
Version: 0.47-2
Section: universe/editors