Re: Best way to detect font-lock mode is on?

[Stefan Monnier <monnier@iro.umontreal.ca>]

> Yes, that is how I plan to do it if font-lock is not enabled. I'm
> currently experimenting with syntax-ppss and parse-partial-sexp to see
> if the cached version can be used reliably or if the uncaching variant
> is required and if this has too high a penalty. I have found that with
> syntax-ppss, I do get false positives fairly frequently if I don't first
> call syntax-pps-flush-cache, which would seem to defeat its benefits
> over parse-partial-sexp.

font-lock uses syntax-ppss, so if syntax-ppss is wrong, font-lock should
be wrong as well.

> As the buffer is being edited, potentially changing the syntax at
> random places, it is difficult to determine when the cache will need
> to be flushed (though I have a couple of ideas that may strike an
> acceptable balance).

syntax-ppss is supposed to automatically flush the (relevant part of)
the cache after any buffer modification.  The only exceptions are when
the buffer is modified in a context where inhibit-modification-hooks is
set (e.g. font-lock-syntactic-keywords).

>>> As you can see, I'm using font-lock-defaults to test whether font-lock
>>> is enabled. Is this the best way to go or is there a more
>>> reliable/better test to use?
>> Any reason not to use `font-lock-mode'?
> Only that some people don't like to use font-lock. I wanted the mode's
> functionality to be independent of font-lock and not force people to use
> it.

No, I mean to use the variable `font-lock-mode' rather than
`font-lock-defaults'.


        Stefan