Re: cc-mode fontification feels random

[Dmitry Gutov]

Hi Alan,

On 06.06.2021 14:53, Alan Mackenzie wrote:

> > Would it work much worse if you took the approach of not applying the
> > highlighting when you frequently cannot be sure of what the type of the
> > term is?
>
> Cases of "not being sure" are common indeed.  The whole of CC Mode is
> based on heuristics.

I would differentiate between approaches like

  need to parse around the callsite/usage site [of identifier]

and

  need to parse the identifier's definition itself

and, as far as Emacs major modes go, only used the first approach, plus 
perhaps some predefined/customizable list of built-ins.

Because it's pretty much a given that in a big enough project a lot of 
functions/classes/etc will be defined in files that the user will never 
visit in the current session.

> > That would mean none of the types in brackets would be highlighted in
> > the original example, but perhaps that is still better than the current
> > result?
>
> That would mean adding complicated decision functions for "not being
> sure".  If the fontification of types where they are used (as opposed to
> being declared) were to become less common, people would notice and
> complain too.

Some might be relieved, too, seeing more stability of what is highlighed 
and what is not (and when).

> There's the idea I proposed in my post to Daniel C of today - when a
> type is newly recognised, then go through the buffer fontifying
> occurrences of it.  That would probably help a lot, possibly at the cost
> of slowing the mode down a bit.

What about the types that are defined in files you never visited?