bug#61655: [Tree sitter] [Feature Request] font-lock function calls, definitions, separately

[Randy Taylor]

On Thursday, February 23rd, 2023 at 21:31, Dmitry Gutov <dgutov@yandex.ru> 
wrote:
> 
> On 23/02/2023 20:15, Eli Zaretskii wrote:
> 
> > > Cc:61655@debbugs.gnu.org
> > > Date: Wed, 22 Feb 2023 23:38:04 +0200
> > > From: Dmitry Gutovdgutov@yandex.ru
> > > 
> > > On 22/02/2023 22:45, Yuan Fu wrote:
> > > 
> > > > Yeah that’s just an idea, and I don’t have problem adding faces. But we 
> > > > probably can’t keep adding more and more specific faces. At one point 
> > > > we’ll need to either add indirection, or ask users to just add their 
> > > > own fontification rules, if it is really specific. We’ll see.
> > > > An indirection seems like a separate new feature. Might be useful for
> > > > some, but probably unnecessary for this discussion.
> > > 
> > > > Function definition & call is totally reasonable. But adapting all the 
> > > > major modes to use them is might be too big a change for emacs-29.
> > > > The change itself should be very straightforward. If we agree on the set
> > > > of faces (for variables and properties as well, right?), I don't mind
> > > > posting a patch for review.
> > > 
> > > Whether it gets accepted or not.
> > > I'm okay with adding a few more faces to emacs-29, but please hurry,
> > > as we don't have too much time for more additions.
> 
> 
> Here's the patch which adds the faces and their uses in all ts modes.
> 
> Comments welcome from all the interested parties. The patch is mostly
> straightforward, but there are some changes added as well, where it was
> needed to differentiate between declarations and references.
> 
> The important question here, I think, is whether we want to split
> font-lock-property-faces in two, like I did here.
> 
> By analogy with the other faces, I think it's going to be useful to
> differentiate between property definitions and property references. Not
> many of the languages modes used font-lock-property-face for
> property/attribute definitions, but some did.

I'm not sure about the naming of font-lock-variable-ref-face. It's confusing 
for languages that support actual references like C++ and Rust.

Maybe the opposite direction is better: font-lock-variable-def-face (or 
something similar) for definitions (or whatnot), and 
font-lock-variable-name-face to refer to uses (same goes for property). Or 
font-lock-variable-use-face. I don't know, naming is hard :).

Personally, I don't really see the value in differentiating these for 
variables. I can understand it a little more for properties. But I guess it 
doesn't hurt to add if folks want it.