(Typescript) highlight obvious user defined type names (`interface`, etc)

[amirqasemi74]

See this example:

as you can see in boudingRect params the Rect type has not been highlighted. also interface name.
I think these one should be highlighted

[joshgoebel]

This is because we are not a full TypeScript parser (nor do we desire to be), we're more of a "fancy pattern matcher". As such it's impossible to know that Rect[] there is a type... For some languages we can examine the immediate context but in this case that is also insufficient. : is used in many places in JS and ) isn't helpful.

Note: The [] in this case is strange, but even if that were a strong signal that would only allow us to detect Blah[] types, not all types in general, and therefore it'd be even more confusing - vs now where we highlight the "standard" types always, and simply do not highlight user types.

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I'd love to see someone attempt a plugin/grammar pairing that hooked up an entirely different parser - with our HTML generation. https://github.com/codemirror/lang-javascript would be a good choice I think. If you're interested in a project like that, let us know.

[joshgoebel]

Rules could be added for the simpler cases such as interface [type]... this would be a perfect use for our new multi-class matcher support... but that doesn't help with params or types in other contexts.

[joshgoebel]

Rules could be added for the simpler cases such as interface [type]...

Tagging as "good first issue" as these simple cases shouldn't be too hard and there are examples from other modern grammars, like Wren.

[joshgoebel]

Also worth exploring if this could somehow just be handled by a general CamelCaseIsAClass rule...

[deepto98]

@joshgoebel I can pick this up, but will need some guidance as to which existing examples/files I can refer to and how I should approach this

[joshgoebel]

I dunno about samples. I think start might be just a CamelCaseIsAClass as mentioned above which we already have examples of in Ruby and JS I think?