font-lock-maximum-size

font-lock-maximum-size

[Chong Yidong]

  font-lock-maximum-size is a variable defined in `font-lock.el'.
  Its value is 256000

  Documentation:
  Maximum size of a buffer for buffer fontification.
  Only buffers less than this can be fontified when Font Lock mode is
  turned on.

Looks like this variable doesn't work, and hasn't worked for a long
time.  It nothing when JIT lock mode is in use, and since fast-lock and
lazy-lock are obsolete, it's pretty useless.  (Anyway, source files
larger than 250K are not uncommon.)

If there are no objections, I am going to mark it as deprecated, and
remove it from the manual.

Re: font-lock-maximum-size

[Alan Mackenzie]

Hi, Yidong.

On Mon, Oct 17, 2011 at 05:19:21AM -0400, Chong Yidong wrote:
>   font-lock-maximum-size is a variable defined in `font-lock.el'.
>   Its value is 256000

>   Documentation:
>   Maximum size of a buffer for buffer fontification.
>   Only buffers less than this can be fontified when Font Lock mode is
>   turned on.

> Looks like this variable doesn't work, and hasn't worked for a long
> time.  It nothing when JIT lock mode is in use, and since fast-lock and
> lazy-lock are obsolete, it's pretty useless.  (Anyway, source files
> larger than 250K are not uncommon.)

Doesn't it work when no font-lock-support-mode is in operation?

> If there are no objections, I am going to mark it as deprecated, and
> remove it from the manual.

I don't object - even if it were still operational, modern PCs are so
fast now that f-l-max-size would have to be so big to be sensible that it
would exceed the size of nearly all source code buffers.

However, please don't ever downplay the usefulness of (eq
f-l-support-mode nil).  This is very useful for debugging f-l-keywords,
etc., and also works well when jit-lock doesn't - I've had quite a few
problems with font lock over the years, many of them being caused by a
jit-lock chunk starting in the middle of a (largish) syntactical
construct.

-- 
Alan Mackenzie (Nuremberg, Germany).

Re: font-lock-maximum-size

[Stefan Monnier]

> Looks like this variable doesn't work, and hasn't worked for a long
> time.  It nothing when JIT lock mode is in use, and since fast-lock and
> lazy-lock are obsolete, it's pretty useless.  (Anyway, source files
> larger than 250K are not uncommon.)

It does work, but only when setting font-lock-support-mode to nil
(which makes sense if you consider that the purpose was to avoid
performance problems with the eager fontification of large buffers).

> If there are no objections, I am going to mark it as deprecated, and
> remove it from the manual.

Fine by me, tho I agree with Alan that font-lock-support-mode is not
obsolete (it's indispensable to debug font-lock problems).


        Stefan

Re: font-lock-maximum-size

[Chong Yidong]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> If there are no objections, I am going to mark it as deprecated, and
>> remove it from the manual.
>
> Fine by me, tho I agree with Alan that font-lock-support-mode is not
> obsolete (it's indispensable to debug font-lock problems).

Done.