Improve Haskell highlight queries

[farbodsz]

This PR makes improvements to the highlights.scm file in tree-sitter-haskell.

It's partly based off the one by @elianiva from https://github.com/nvim-treesitter/nvim-treesitter/pull/1210. (I'm aware that PR is still in the works, so wasn't sure whether to open the PR here or on the nvim-treesitter repo).

Here are the changes I've made compared to the one from the nvim-treesitter PR:

• Highlight minus sign in negated numbers, e.g. (-10)
• Resolve error when comma captured as punctuation delimiter (previously commented out)
• Add semicolon as punctuation delimiter
• Add case and of to @conditional capture group
• Move qualified out of @keyword and into @include capture group
• Add missing operators:
  • type_operator
  • Dots from export and record wildcards, i.e. Record{..}, exp (..)
  • Equals and pipe = and |
  • Function arrows => and ->
  • Bind arrow <-
  • Lambda operator \
  • Treat infix functions as operators (and also highlight the backtick)
  • @ symbol (except for in the as-pattern, where it is highlighted as @namespace)
• Highlight namespaces with @namespace instead of @constructor, e.g. in T.Text
• Simplify queries for types

There's also a comparison of each of the aforementioned highlights, so you can see the results visually.

Example 1

tree-sitter-haskell	nvim-treesitter PR	This PR

Example 2

tree-sitter-haskell	nvim-treesitter PR	This PR

[tek]

wait, this is rendered by nvim? any clue if there was some recent change that made this possible? I've been having issues like this one https://github.com/tree-sitter/tree-sitter-haskell/issues/35

anyways, looks good!

[farbodsz]

Thanks for merging! Yes, it is rendered by nvim.

While I haven't been able to reproduce the exact issue you mentioned, I have noticed Playground not updating at all (for all languages). Not sure if those issues are related but I might look into it further in the near future.

[theHamsta]

@elianiva shouldn't qualified be also @include for us?

[elianiva]

@elianiva shouldn't qualified be also @include for us?

I think it should, but isn't it already the case though?