Haskell-indentation breaks on Unicode

[Roel van Dijk]

Consider the following program:

{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE UnicodeSyntax #-}

module Test where

foo ∷ ∀ α. Ord α ⇒ α → α → α
foo x y | x ≥ y     = x
        | otherwise = y
    where
      (≥) ∷ ∀ β. Ord β ⇒ β → β → Bool
      (≥) = (>=)

If I position the point on the first line after the function foo and press tab I get a "Parse error" message. The problem seems to be in the parsing of the (≥) operator. The following snippet does not have the parsing problem:

bar ∷ ∀ α. Ord α ⇒ α → α → α
bar x y | x $>= y    = x
        | otherwise = y
    where
      ($>=) ∷ ∀ β. Ord β ⇒ β → β → Bool
      ($>=) = (>=)

[Baughn]

The latest patch appears to have fixed this problem to some degree; although the indentation is way off, at least there are no more parse errors.

[Baughn]

These indentation issues are not particular to unicode symbols, however, and have been there a while.