stylish-haskell integration no longer reports errors

[MichaelXavier]

Often in haskell development, the buffer I'm working on will be invalid for stylish haskell: missing MultiParamTypeClasses, syntax error, etc. If I recall, stylish-haskell used to drop the error it was getting into the minbuffer. Recently, is just says: "Error: stylish-haskell ended with errors, leaving buffer alone". In order to fix the error, I have to leave my editor and manually run stylish-haskell file.hs | head to get the error. Seems like the formatter should capture the stderr of the process and leave it somewhere.

[gracjan]

This change was motivated by #401 and done in #557.

As we do not know if buffer is or is not valid Haskell it is an expected condition that stylish-haskell fails. if you wish it reported then we need to find a better way of handling the error. The previous one was way to invasive.

Also what is the point of handling stylish-haskell error? Does not your normal GHC say that you need to enable this and that extension?

@MichaelXavier: do you have a more concrete proposal?

[lukehoersten]

I would recommend using something like flycheck-haskell to check for errors on the fly since it is purpose built for that. Stylish-haskell is only reporting why it couldn't format your code and isn't intended for on-the-fly debugging like flycheck is.

[MichaelXavier]

@lukehoersten I'm not really trying to use stylish-haskell for debugging. There are cases if I recall where the program will compile but stylish-haskell will refuse to parse it (I think to do with missing extensions like MultiParamTypeClasses). Sometimes you're concerned with formatting independently of errors in the code.

@gracjan Thanks for the heads up. That works for me! One thing I'd recommend though is maybe to recommend setting warning-minimum-log-level to debug rather than warning-minimum-level. That seems like it would satisfy more people because it won't pop up in your face but it won't suppress the actionable information from your warnings buffer either.