Re: Font-lock in COMINT modes

[JD Smith]

On Fri, 08 Dec 2006 23:02:29 -0500, Stefan Monnier wrote:

>> I haven't understood how a purely nil font-lock-defaults implicitly
>> prevents string+comment fontification independent of the keywords-only
>> setting, but it does.
> 
> Because if it's nil font-lock-mode-internal is not activated at all. AFAIK
> nil and (nil t) are equivalent (i.e. don't highlight anything), except
> that (nil t) takes a lot more CPU to do nothing (it runs all the
> font-lock-foo-function hooks, enables jit-lock so as to do nothing
> just-in-time rather than eagerly, checks where nothing needs to be done,
> rounds up to a whole number of lines the region upon which inaction is
> requested, checks if there's a multiline entity and extends the region
> even more, so that nothing is done in a multiline awaer way, ...).

Classic ;).

My presumption is that '(nil) and nil must differ in some other
way (aside from the unintended side effect of changing the default
non-keyword fontification), since the original change from Sept.
explicitly bound f-l-defaults non-nil, which by inference suggests nil and
'(nil t) would exhibit this same difference, whatever it is.