Re: Criticism of jit-lock--antiblink-post-command

[Stefan Monnier]

>> The intention is that when it's not useful it's harmless.
>> IOW if there's a good reason to turn it off, it's probably a bug.
> I don't think I agree.  A post-command-hook that is not useful just
> takes CPU cycles, and likewise a timer which does nothing when its
> function is invoked.

AFAIK we don't try very hard to avoid such waste.
E.g. every time we run redisplay, it will check at every position if
there is a `display` or `invisible` property, even in those buffers
where no code ever has nor ever will add one of those properties.
[ This is just a random example, we have loads more, of course.  ]

> And in any case, a feature that changes behavior should have a knob to
> disable it.

We like such knobs in Emacs, indeed.  My argument was not against having
such a knob (which is already present in the suggested patch, AFAIK) but
in favor of keeping the feature enabled by default and encouraging
people to report problems when the encounter them rather than just turn
off the feature.


        Stefan