eldoc support? about lsp-haskell

[walseb]

I messed around with this a lot during the summer break. The problem is that the LSP.el requires a particular command from the LSP spec to be enabled on the LSP implementation (lsp-haskell in this case) for eldoc to work. This command isn't enabled in lsp-haskell (no idea if HIE supports it though). Lsp-ui can show the types without a problem because it requires a different command which is enabled on lsp-haskell. Same goes for the other lsp functions that can see types, like check docs. The way I solved this was by overwriting the lsp-ui function which is stealing the type info lsp-ui generates and then giving it to eldoc instead https://github.com/walseb/QualityEmacsConfig#hack-in-eldoc-support . But this problem could probably be fixed by just telling LSP.el that the eldoc request command is enabled, since it should be supported by HIE

[mohkale]

wow, did not expect a solution/response that quickly. Thank you 😄 😄 😄 now let me just do some hardcore analysis blatant copy and paste of what you've shared.

[walseb]

No problem! There is one problem with it though atleast on my pc, changing lines sometimes results in eldoc not printing the type info. This could probably be fixed with a timer or something. It happens because lsp-ui sometimes doesn't fetch the type info in time for them to be printed by eldoc. Oh and sometimes there are also boxes on the right side of the screen. Those are remains of lsp-ui that I couldn't figure out how to remove

[mohkale]

okay. pretty sure the command you mean is signature-help because it sounds like what it should and because its refrenced in the docstring for lsp--signature->eldoc-message. I also believe this might be an issue on haskell-ide-engine raised to adress it... though its been pushed back quite a bit 😭😭😭.

[michaelpj]

It sounds like the issue here is support for the signatureHelp requests in the language server, i.e. haskell-language-server. If the server supports it then lsp-mode should do the right thing. Could you open an issue in haskell-language-server, please (assuming it hasn't been fixed already)?