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

[Jeff Norden]

> Eli Zaretskii writes:
>
>> Sorry for not being more clear.  I meant deleting
>> font-lock-support-mode: it must be declared obsolete first (which
>> would require adding the command proposed by Stefan), then, after some
>> obsolescence time, we could delete font-lock-support-mode, and then we
>> can delete fast-lock and fuzzy-lock.
>
> Ah, okay.  So if I understand correctly we should not pull the trigger
> on deleting the libraries fast-lock and fuzzy-lock until we have first
> obsoleted and, at a later date, deleted font-lock-support-mode.
>
> Best regards,
> Stefan Kangas

I feel like I may be responsible for creating this little mess.  I'm not
sure if I can help clean it up, but I'll try.

Stefan K's original patch was to just delete the old fast-lock and
lazy-lock libraries.  This didn't delete the font-lock-support-mode
variable, but it would have implicitly changed its role.  Instead of
choosing a "support" mode, the only valid values would have been
'jit-lock-mode or 'nil, the latter for debugging.

For all practical purposes, this has actually been the case ever since the
old libraries where obsoleted.  Currently, setting f-l-s-m to anything
other than 'jit-lock or 'nil will only work if you explicitly load one of
the old libraries from the obsolete/ directory.

When I saw the patch, I decided to butt in, and suggested that this would
make the already confusing name "font-lock-support-mode" even more so.
(In hindsight, perhaps f-l-acceleration-mode would have been a better,
albeit even longer, choice.)  I stuck my nose in here because I've recently
been figuring out the details of how font-lock works, and this was one of
the stumbling blocks.

So, I tried to suggest a new variable name, with font-lock-support-mode as
an obsolete-variable-alias.  Stefan M suggested, I think, replacing f-l-s-m
with a minor mode for debugging font-lock.  Anything that makes it easier
for someone new to figure out how to debug their font-lock code when it
fails to work properly would be good.  In any case, it is obviously
important that setting font-lock-support-mode to 'nil should continue to be
supported as a (perhaps obsolete) way of disabling jit-lock without turning
off font-lock.

Thanks, and sorry if I've been the cause of some confusion.

Regards,
-Jeff

BTW: Does anyone know the origin and/or meaning of the use of '-lock' in
font-lock, etc?