Investigate improvement of Haskell syntax highlighting

[nekowinston]

From the Discord.

Test the syntax hl with https://github.com/JustusAdam/language-haskell / https://marketplace.visualstudio.com/items?itemName=justusadam.language-haskell
More random Haskell code: https://rosettacode.org/wiki/Category:Haskell

[nekowinston]

Honestly couldn't find many places where there would be obvious improvements, but I'm also not far into my Haskell journey yet. Closing this, as I won't continue work on this.

[DavSanchez]

Hey! Sorry for posting on a closed issue, but I was just searching for any effort in Haskell improvements with these awesome themes and stumbled upon this one.

I'm not sure if the Catppuccin themes could be configured to solve this issue away, but one area of improvement could be the colouring of data constructors. Take as example the last line shown in this function (the SuggestedMatch word), both in Cappuccin Mocha:

and Lambda Dark+ (from the Lambda Black extension):

This Lambda Black themes were made with Haskell specifically in mind (among others in the FP space like Nix), so not sure if following the approaches from that extension could compromise existing design decisions for Catppuccin.

[nekowinston]

Pinging @backwardspy so that they can see your comment. I've stopped maintaining this theme (but funnily enough picked up Haskell as one of my go-to programming languages since).

The missing highlight for the SuggestedMatch Type is probably just a result of missing Semantic (LSP-aware) highlights, as HLS is making heavy use of these.

[carlwr]

Fixed by #559.

SuggestedMatch in #360 (comment) colors correctly with that PR.