Re: Last steps for pretesting (font-lock-extend-region-function)

[Stefan Monnier]

>> I'm not saying the hook is a kludge: I'm saying the code that uses it is
>> a kludge, compared to the code that uses font-lock-multiline.

> OK.  I feel that existing code in AWK Mode is natural.  (OK, I wrote it,
> so I'm not in a position to judge it dispassionately, but ...).  It notes
> the logical EOL before a change.  It notes the logical EOL after a
> change.  The later one is the end position for fontification.

Why doesn't the BOL before change matter?
Why does the EOL before change matter?

> By contrast, the f-l-multiline method (ab)uses the structure for setting
> face properties to set region boundaries for possible future changes.

Abuses the structure of what?

There two issues about multiline elements:
- properly notice them when they appear
- properly *re*fontify them when they change

The first is taken care of by font-lock-fontify-region-function.
The second talks about *re*fontification, so it's natural that it would
involves saving some info during fontification for the next time around.

Doing it in a-c-f is fundamentally not the right place since it doesn't know
whether and how the changed text was fontified: it works, of course, but
it's not particularly more natural.


        Stefan