Haskell Syntax highlight break when write a type signature with "=>" sign

[foxmean]

Summary

Around 95% up when I write a type signature with "=>" sign, the syntax highlight is break. Everything is recover when I quite and reopen the helix as show below.

Reproduction Steps

I tried this:

1. Open the helix editor and write some Haskell script
2. Everything worked just fine except when I wrote a type signature that included "=>" sign (mostly). I usually not happen when I haven't included "=>".
3. When I save and restart helix, everything fixed. But it is annoying.

I expected this to happen:
The syntax highlighter maybe break due to incomplete writing since it haven't happened if I wrote the function definition before type signature as show below

Instead, this happened:
When I wrote a type signature before the function definition

Helix log

A copy of ~/.cache/helix/helix.log here (with RUST_BACKTRAACE=1 hx -vv when reproducing bug. I have no idea how to summary these lines but I have selected only line that I reproduced the bug here.

Platform

MacOS Sonoma 14.6.1; on MacBook Air M1, 2020

Terminal Emulator

iTerm2, Build 3.5.0 (without terminal multiplex); and Alacritty Version 0.13.2 (1) with Zellij 0.40.1. Both terminal was installed via homebrew cask. Zellij was installed via nixpkgs (nix-darwin)

Installation Method

nixpkgs through nix-darwin flake

Helix Version

helix 24.7 (079f544)

[kirawi]

We disable highlighting on a buffer if highlighting takes longer than half a second to compute. It sounds to me like => has some buggy behavior here. We could see if a newer commit for the grammar has resolved this issue.

[foxmean]

Sorry for the last archived video. I can reproduce some of the bug related to just "->" too like.

BTW, I think the bug is from HLS itself due to I can reproduce it in Zed editor.
I use GHC 9.10.1 with HLS 2.9.0.1 from GHCup

[foxmean]

We disable highlighting on a buffer if highlighting takes longer than half a second to compute. It sounds to me like => has some buggy behavior here. We could see if a newer commit for the grammar has resolved this issue.

Where is the place that I should follow for this issue or take a look if someone fix it already in development build or anything I can do for help fixing it?

[foxmean]

I've try to change timeout in [language-server.haskell-language-server] as in the documentation specified to something like 6_000_000 but the bug still wasn't fixed.

[RoloEdits]

You can try to update the tree sitter grammar for Haskell to see if there a parser error was fixed.

https://github.com/tree-sitter/tree-sitter-haskell

Current rev if from Sep 24, 2023.

https://github.com/helix-editor/helix/blob/cbbeca6c5227e65bebdbe9abbadbd2202ffc1005/languages.toml#L1348-L1361C79

[foxmean]

One thing I found wired is that I cannot reproduce it in Neovim (NVIM v0.10.2, Build type: Release, LuaJIT 2.1.1731601260). But consistently reproducible with Helix .

[david-d-h]

+1 still happening for me, doesn't happen if the type definition is the only thing in the file
haven't tested in other editors

[foxmean]

I am currently have no skill to tackle this problem which I think it is about Haskell's tree-sitter grammar rewriting, since this bug is also reproducible with other editor(s) like Zed. However, I've found another workaround (if you don't want to just quit & reopen the file) for Helix: you can use :config-reload command and the syntax highlighting will be back.

[CalebLarsen]

@foxmean Will you try building from source and let me know if you are still experiencing this issue?
#12972 was a huge change to how we work with tree-sitter.

[foxmean]

@foxmean Will you try building from source and let me know if you are still experiencing this issue? #12972 was a huge change to how we work with tree-sitter.

Yeah, it works! (I've tested bcb6c20a. I think it is the same as this one bcb6c20) Thank you so much for you and helix team. Waiting for next official release. Should I close this issue?

[CalebLarsen]

I think we're good to close the issue, thank you!