Can't compile unicode symbols

[4lex1v]

When i type something with haskell-mode, it replaces std symbols with prettier unicode alternatives, e.g:

function :: Ord c => c -> (c, c)
with
function :: Ord c ⇒ c → (c, c)

But when i hit haskell-process-cabal-build i throws me these errors:

Not in scope: type constructor or class ‘⇒’
Not in scope: type constructor or class ‘→’

I've added an extension to .cabal file : extensions: UnicodeSyntax, but it didn't help. I like unicode symbols, but can't compile files.

[gracjan]

Hi @4lex1v,

Try the following: Add this line at the top of Haskell source file:

{-# LANGUAGE UnicodeSyntax #-}

and report back. Also can you upload your source file somewhere, for example http://lpaste.net/ is a good place for Haskell code.

[geraldus]

extensions: UnicodeSyntax

should it be default extensions:?

[4lex1v]

@geraldus Thank you, correct, it should be default-extensions and it should be placed under the library section.