IHaskell support

I’m trying to use the ghcide LSP server for Haskell with this extension, with these Language Server User Preferences:

{                                     
  "language_servers": {                    
    "ghcide-language-server": {            
      "version": 1,                        
      "argv": ["/opt/bin/ghcide", "--lsp", "--verbose"],
      "languages": ["Haskell"]             
    }                                      
  }
}

After the message LSP: Untitled1.ipynb ready for connection, an error is thrown from this line:

https://github.com/krassowski/jupyterlab-lsp/blob/f305ab4e1d8ff6b62daffe1460636175406a00df/packages/jupyterlab-lsp/src/adapters/jupyterlab/jl_adapter.ts#L212

this is of type NotebookAdapter, and this.mime_type is undefined, and the error says:

react_devtools_backend.js:2273 TypeError: Cannot read property 'split' of undefined
   at NotebookAdapter.get language [as language] (jl_adapter.js:126)

[jamesdbrock]

Thanks @krassowski and @bollwyvl , This is a really nice JupyterLab extension, I hope we can get it working for IHaskell.

[jamesdbrock]

As you guessed @bollwyvl , .hs files seem to work but Haskell notebooks not so much.