error-message-index VS debug-adapter-protocol

Significant effort is going into resolving this issue right now and things should be much improved in 9.6. We already have https://errors.haskell.org/ which catalogues many errors with descriptions and examples. The asspciated error codes will be added to all errors once 9.6 is release for easy reference.

We're also delighted to announce integration with errors.haskell.org, which already has a couple of GHCup codes documented, e.g. https://errors.haskell.org/messages/GHCup-00010/

To support the Haskell Foundation’s Haskell Error Index initiative, all Stack error messages generated by Stack itself begin with an unique code in the form [S-nnnn], where nnnn is a four-digit number.

I don't think the resolved issues are actually ones about error messages. They largely seem to be meta issues about the project. As far as I know nothing that project has done has made it into a released GHC yet, but GHC 9.6 will have unique error codes for each error pointing to an entry on https://errors.haskell.org/. Both the codes and the website are achievements of that project, specifically under its error-messages-index incarnation. If you'd like to contribute you may like to read https://github.com/haskellfoundation/error-message-index/blob/main/CONTRIBUTING.md or post a message introducing yourself on https://github.com/haskell/error-messages/issues/new.

> There's a strange dance of IDEs coming and going, with their idiosyncracies and partial plugins.

The Language Server Protocol [1] is the best thing to happen to text editors. Any editor that speaks it gets IDE features. Now if only they'd adopt the Debug Adapter Protocol [2]...

[1] https://microsoft.github.io/language-server-protocol/

[2] https://microsoft.github.io/debug-adapter-protocol/

Wonder if they've got support for Debug Adapter Protocol? https://microsoft.github.io/debug-adapter-protocol/

> Debuggers need to do more things

It's true that coming up with an interface for an abstract debugger is harder, but it's not impossible. Microsoft create Debug Adapter Protocol (https://microsoft.github.io/debug-adapter-protocol/), which is conceptually similar for LSP. It's not perfect, but covers most basic operations pretty well, while leaving to the debugger to deal with the implementation details.

Most languages also include support for the Debug Adapter Protocol, and Haskell is no exception, so if you are so inclined, you can hook up your favorite editor/IDE and go to town.

They're working on the Debug Adapter Protocol but it doesn't have critical mass/adoption yet. And yeah, I end up having a fair share of dbg!(foo). It's not so bad since dbg!() also returns its value, so you don't have to mess with your code too much.

TL;DR: What would it take to implement a Debug Adapter Protocol (DAP)-based step debugger?

RDP is the Windows Remote Desktop Protocol that was in use for decades before VSCode; VSCode's own remoting doesn't use it.

I'd say that, in addition to LSP, the other big thing that came out of VSCode is DAP: https://microsoft.github.io/debug-adapter-protocol.

The most important part is the JDT Languag Server, it will give you the Java tooling for writing code. I think it has DAP support as well, so with a DAP client like nvim-dap you should be able to debug as well.