Enable eval plugin to run in its own terminal and enable terminal to be piped to a log file

[theGhostJW]

Is your enhancement request related to a problem? Please describe.

I just discovered that in VSCode the eval plugin logs to the Haskell Output window in addition adding the result to the code editor.

Code to Eval

-- >>> helloWorldNonInteractive
-- "DONE"
helloWorldNonInteractive :: IO Text
helloWorldNonInteractive = putStrLn "Hello, World!" >> pure "DONE"

VSCode Haskell Output

2024-08-24T23:53:08.298464Z | Info | Live bytes: 95.98MB Heap size: 718.27MB
2024-08-24T23:54:08.351720Z | Info | Live bytes: 95.98MB Heap size: 718.27MB
toIfaceIdDetails [DataConWrapper]
toIfaceIdDetails [DataConWrapper]
toIfaceIdDetails [DataConWrapper]
Hello, World!
2024-08-24T23:55:08.383369Z | Info | Live bytes: 95.98MB Heap size: 718.27MB

It is also apparent that the output that is interleaved with the HLS logs are not copied to file when that option is selected in VSCode settings.

haskell.log

2024-08-24T23:54:08.351135Z | Info | Live bytes: 95.98MB Heap size: 718.27MB
2024-08-24T23:55:08.382573Z | Info | Live bytes: 95.98MB Heap size: 718.27MB
2024-08-24T23:56:08.436285Z | Info | Live bytes: 95.98MB Heap size: 718.27MB
2024-08-24T23:57:08.481933Z | Info | Live bytes: 95.98MB Heap size: 718.27MB

Describe the solution you'd like

It would be awesome if there could be an option with the eval plugin to output to a separate output window, free of the noise of HLS logs and optionally log the same to a file. Better still if an interactive terminal could be used instead of a an output window. Interactive code seems to bork the current version hls eval (which is understandable given there is no way to interact with a program invoked via eval).

-- >>> helloWorld
-- "DONE"
helloWorld :: IO Text
helloWorld = do
  putStrLn "What is your name?"
  name <- T.getLine
  putStrLn $ "Hello, " <> toS name <> "!"
  pure "DONE"

this will cause a Connection got disposed error

Describe alternatives you've considered

A somewhat similar ux can be achieved with cabal repl or ghcid or more recently ghciwatch but it would be great to be able to do it all with eval

[theGhostJW]

somewhat related to #1977 and #2913

[dschrempf]

I also think the eval plugin needs to be improved in this regard. However, I don't see how we can output to "another terminal". HLS is a command line application and, if --lsp mode is activated, HLS communicates directly with an LSP client (usually an editor, for example, VSCode).

The editor does not understand that HLS writes to a separate file handle. We can use features of the language server protocol to communicate with the editor, I am not sure which one though.

In the first run, I think we should either wrap stdout and stderr into proper log messages sent to the log stream.

Then, we can think of an additional feature using the LSP, sending the side-effect output back to the client.

[dschrempf]

This issue may be fixed by 4726, which prepends stdout and stderr to the result of the evaluation.

The second part of this issue is a duplicate of #2913, as far as I can see.