Re: "Use font-lock-support-mode rather than calling lazy-lock-mode"

[ishikawa]

Richard Stallman wrote:
>     But from the lusers's point of view, it would be nice to
>     have a guideline of how to move over to newer and more powerful
>     libraries/packages such as jit-lock from lazy-lock.
>     (Info doesn't seem to have been updated...
>
> Would you please be more specific?
> Please show the text that "doesn't seem to have been updated",
> and say the title of the section.  Then we can fix it.

OK?

I was not specific, and was not accurate enough.

After checking the info files for both emacs 21.4 and 22.0.90, I realize
that I should have said, "Info" itself was not very friendly to novice users
like me concerning "Font Lock" while the messages associated with related
lisp symbols from font-lock packages were.

This is especially so in the case of font-lock-support-mode variable.

I propose that we incorporate the message text for lisp variable 
`font-lock-support-mode' into Emacs Info file, specifically, into
the section "19.7 Font Lock mode".

The help message printed by C-H v font-lock-uspport-mode is quoted below.

---QUOTE---
Documentation:
*Support mode for Font Lock mode.
Support modes speed up Font Lock mode by being choosy about when fontification
occurs.  The default support mode, Just-in-time Lock mode (symbol
`jit-lock-mode'), is recommended.

Other, older support modes are Fast Lock mode (symbol `fast-lock-mode') and
Lazy Lock mode (symbol `lazy-lock-mode').  See those modes for more info.
However, they are no longer recommended, as Just-in-time Lock mode is better.

If nil, means support for Font Lock mode is never performed.
If a symbol, use that support mode.
If a list, each element should be of the form (MAJOR-MODE . SUPPORT-MODE),
where MAJOR-MODE is a symbol or t (meaning the default).  For example:
 ((c-mode . fast-lock-mode) (c++-mode . fast-lock-mode) (t . lazy-lock-mode))
means that Fast Lock mode is used to support Font Lock mode for buffers in C or
C++ modes, and Lazy Lock mode is used to support Font Lock mode otherwise.

The value of this variable is used when Font Lock mode is turned on.

You can customize this variable.

--- END QUOTE ----

I bet many old people like me still prefers to read the manual in printed form 
and so having this information in the Info file (which could be printed into a 
nice looking primted manual) is a good thing, IMHO.

Also, I have learned by looking this help message that jit-lock-mode is the
default value and thus I don't have to muck around to replace the setting
of font-lock-support-mode. I think I haven't needed to tinker with the value of 
font-lock-support-mode except for my experience with a certain version of VM
a few years ago. (I forgot the details now.)

NOW, WAIT A SECOND.

I think the original warning message that got me started for this search
might have been better re-phrased to something like,
"Use jit-lock-mode rather than `lazy-lock-mode'."

Isn't this the case after all? Or am I missing the intent of the warning 
message?

Happy Hacking,
Chiaki Ishikawa