Why not enable font lock by default?

[David Kastrup]

Ville Skyttä <scop at xemacs.org> writes:

> On Friday 06 July 2007, Jason Spiro wrote:
>> 2007/7/3, Mike Kupfer <mike.kupfer at sun.com>:
>> > The one concern that I have about enabling font lock by default is that
>> > it can be slow, i.e., when editing large files on relatively slow
>> > hardware.
>>
>> If somebody feels it is too slow for them, they can disable it using
>> the drop-down menus or using M-x customize.  But the vast majority of
>> people would benefit from it.  :-)
>
> My late .02€ to the discussion: MHO is that plain vanilla font-lock
> is too slow to be enabled by default.  But I wouldn't object at all
> to lazy-lock enabling font-lock and itself automatically when
> installed, provided that there's a sane way to do it without
> trumping the user's choices such as preference of lazy-shot over
> lazy-lock, or preference to have no font-lock and no lazy-lock and
> friends no matter if they're installed or not.

As a reference point: font-lock-mode is the default in Emacs 22.1.  A
combination of lazy-lock, a general font-lock pattern cleanup during a
long test phase, and fixes and additions to the font-lock core were
necessary before this default was deemed acceptible.  This brought
forward the state of font-lock from 21.1 to 22.1.  The XEmacs
font-lock engine, IIRC, roughly corresponds to the state in Emacs
20.7.

I would think it likely that the usability objections against enabling
font-lock in Emacs 21.1 and post-21.1 would hold similarly for the
current XEmacs code base.

I think that the font-lock area is one area where an Emacs synch (that
you are still dealing with GPLv2+ at the moment might make this a
somewhat "natural" point for synching) would really make sense.
AUCTeX already has inferior syntax highlighting on XEmacs.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum