compilation fails with ghc >= 7.10 since notElem uses Foldable now

[jwaldmann]

[2 of 2] Compiling Language.SMTLIB  ( Language/SMTLIB.hs, dist/build/Language/SMTLIB.o )

Language/SMTLIB.hs:819:22: error:
    • Ambiguous type variable ‘t0’ arising from a use of ‘notElem’
      prevents the constraint ‘(Foldable t0)’ from being solved.

for this snippet of code:

clean = filter (flip notElem " \t\r\n") . unlines . map (takeWhile (/= ';')) . lines

Because of:

notElem :: Eq a => a -> [a] -> Bool   -- for ghc up to 7.8.4
notElem :: (Eq a, Foldable t) => a -> t a -> Bool -- since ghc 7.10.3 (at least)

The fix is trivial ( 2f072c7 )

clean = filter (flip notElem (" \t\r\n" :: String)) . unlines . map (takeWhile (/= ';')) . lines