initial implementation of goto types and separating annotations

[Acepie]

An initial implementation for making annotations distinct from the thing being annotated. Currently in most places where the user hovers over an annotation it either doesn't work or hovers the larger object being annotated (function head, constant, custom type). This change is the first part of separating that out and allowing for operations on the located annotation. Currently that means hovering will display the type itself, completions will always be type completions (this seems to be exactly the same as current in all cases), and goto definition now will go to where the type is declared. There are a couple known gaps here but overall its still an improvement so want to start with this and get feedback

Known things to improve:

• Type aliases seem to be stored in the ast directly as the type being aliased meaning that hover/goto will use the underlying type
• Hovering over a type won't show documentation
• Because of how locations/labels for CustomType constructor args are implemented hovering over the arg label will be treated as hovering over the annotation
  • This is probably fixable but honestly I kinda like it so wanna get thoughts

[lpil]

Because of how locations/labels for CustomType constructor args are implemented hovering over the arg label will be treated as hovering over the annotation

Does that mean if I have this code (][ is cursor)

pub type Thing {
  Thing(value: ][ String)
}

then it shows documentation for type String?

[Acepie]

Yeah because of how the parser sets the location the entire arg is String. We could add some additional information to the AST if we wanna split it but I think the way it seemed to me rn "value" is treated as a label in the AST

[Acepie]

Huh actually, I wanted to test this out after I typed that and I guess somewhere along the line that statement became no longer true and I'm not sure why. Wondering if maybe I had a bug in an earlier version or if there is something I am not remembering rn

[Acepie]

Ok yeah the actual behavior is that the label has no hover (which matches the previous behavior). I think i had a bug at some middle phase that meant i was checking the wrong location and fixed it when I switched to do the TypeAst method of finding the location

[lpil]

Smashing it as always! Thank you!

Left some v small questions

[Acepie]

Ok figured out how to get the documentation on hover for custom types. Ultimately ended up adding documentation to TypeConstructors and then passing it through and looking up the type on hover

[Acepie]

I pulled the windows path fix into #2941

[lpil]

Fab! Really like this, will be a huge improvement to the language server.

There's a few tests I would like to have added here (autocompletions for the various places that annotations can happen) and I'd like to go back to how the definition location method worked before. See the note inline.

Thank you so much!!

[lpil]

Beautiful! Thank you so much!!!