Re: font-lock-syntactic-keywords obsolet?

[Dmitry Gutov <dgutov@yandex.ru>]

On 06/19/2016 06:34 PM, Alan Mackenzie wrote:

>> What's a "logical line"?
>
> What you get when you resolve the escaped new lines, or the non-escaped
> new lines inside a C++ raw string.

But when the raw string is unclosed, it stretches until the end of the 
buffer, doesn't it? Hence, the effects of adding or removing a closer 
must affect the buffer until its end.

> There's no reason to do so, and it would cost a lot of time.  The
> syntax-propertize-function stuff just isn't a good way of impelementing
> CC Mode.
>
> A critical reason, which I've told you before, is that on any buffer
> change, the syntax-propertize-function mechanism blasts all s-t
> properties out of existence from the point the change is made onwards.
> This is wasteful of run-time, given that these properties are quite
> expensive to apply.

They can't be too expensive, considering other language modes, which do 
use syntax-propertize-function, exhibit fewer performance problems than 
CC Mode, even at the same file sizes.

And if the automatic removal of syntax-table properties would lose 
important information, you could save them to a separate structure.

Anyway, you're welcome to propose an alternative general abstraction for 
the same kind of thing than syntax-propertize does. 
font-lock-syntactic-keyword is definitely not that.

>> Maybe you'll need to hand-implement the logic corresponding to
>> syntax-propertize-rules, but that's just work.
>
> In this context, both "just" and "work" are curse words.  :-)

"just implementation work", then. As opposed to "design and implementation".