Re: lazy-lock vs. jit-lock

[Stefan Monnier]

>> If those parts are displayed and yet they're not fontified it's a bug which
>> you should report via M-x report-emacs-bug.

> This is the case.  I'll do a bug report ... but this involves my own mode
> and a not exactly mainstream language, so I wonder how far it will get me.

External code is OK.  Of course the more self-contained the recipe, the
better.  Also a good description of the faulty behavior (what you have to do
to cause it, how it manifests itself, ...) is sometimes enough to understand
the problem (without reproducing it ourselves).

> The fact that jit-lock interacts with Emacs C code is not encouraging,
> I fear I will be asked to gdb Emacs which I won't.

We may ask you to debug it, but you don't have to do it.

>> Lazy-lock has some known bugs (I remember some missing on-screen
>> fontification using outline-minor-mode, for example), >is less efficient<

> Can you expand on the last point?  What makes lazy-lock less efficient?

lazy-lock tries to guess which part of the buffer is displayed, based on
various pieces of information.  But those guesses take work and are
necessarily conservative.  jit-lock on the other hand gets this info from
the horse's mouth without any effort.


        Stefan