Re: [PATCH] Remove obsolete fast-lock and lazy-lock libraries

[Eli Zaretskii]

> From: Jeff Norden <jnorden@tntech.edu>
> Date: Sat, 08 Aug 2020 23:04:42 -0500
> Cc: stefankangas@gmail.com, monnier@iro.umontreal.ca
> 
> A variable name like font-lock-use-jit might be more clear, maybe with
> font-lock-support-mode as an obsolete alias, which would now only have a
> nil-or-non-nil effect.  Perhaps this would be good to do along with 
> removing {fast,lazy}-lock.  If someone has an ancient .emacs that contains
>   (setq font-lock-support-mode 'fast-lock-mode)
> would the best thing be to just use jit-lock-mode instead?  If I'm reading
> the patch correctly, it would make setting the support-mode to fast-lock
> equivalent to setting it to nil.

I see no particular reason to rename the variable, just because it
currently has only one user (inside the core).  It's not like adding
other users is unimaginable, and renaming is always a certain shock,
however small.

> It might make sense to also drop the defcustom status of the support-mode
> variable (or its replacement), since jit-lock is the only non-nil option.

Likewise here: we have many options that have just 2 values, and they
are still defcustom's.

In general, such cleanups are IMO only justified if they bring some
real advantages, or if the variables are no longer used at all.  This
is not such a case.

Thanks.