Support for EmptyCase

[chris-martin]

With -XEmptyCase, this is a valid expression:

\case{}

Stylish-haskell 0.7.1.0 fails on it.

Language.Haskell.Stylish.Parse.parseModule: could not parse foo.hs: ParseFailed (SrcLoc ".hs" 195 23) "Parse error: }"

[osa1]

:+1: came here to report this. I suspect this is because haskell-src-exts doesn't support this extension?

[osa1]

{-# LANGUAGE EmptyCase #-} doesn't work but if I add EmptyCase to .stylish-haskell it parses fine.

[neongreen]

With haskell-src-exts-1.19.1 everything works just fine (you need LambdaCase as well, though):

{-# LANGUAGE EmptyCase, LambdaCase #-}

x = \case{}

I can confirm that the standard build (with hse-1.18) can't parse it, so my advice would be to install stylish-haskell from Hackage or to override the haskell-src-exts choice in stack.yaml when building stylish-haskell with Stack.