so-long and special major modes

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

Emacs distinguishes two kinds of major modes: those that are for a
kind of data, and those that correspond to special applications.  In
the former, q will self-insert.  In the latter, q probably means
"quit".  The way to distinguish is to test the mode-class property of
the major mode symbol.

Dired, Rmail and Info are examples of special major modes.

so-long-major-mode may be ok to use in an ordinary major mode, but it
is no good in a special mode.  In that situation, it is necessary to
use so-long-minor-mode.
 
-- 
Dr Richard Stallman
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)