Proposal: Add a Read instance for Data.Fixed.Fixed http://hackage.haskell.org/trac/ghc/ticket/4502 Patch and test in the ticket; the essence is: readsFixed :: (HasResolution a) => ReadS (Fixed a) readsFixed = readsSigned where readsSigned ('-' : xs) = [ (negate x, rest) | (x, rest) <- readsUnsigned xs ] readsSigned xs = readsUnsigned xs readsUnsigned xs = case span isDigit xs of ([], _) -> [] (is, xs') -> let i = fromInteger (read is) in case xs' of '.' : xs'' -> case span isDigit xs'' of ([], _) -> [] (js, xs''') -> let j = fromInteger (read js) l = genericLength js :: Integer in [(i + (j / (10 ^ l)), xs''')] _ -> [(i, xs')] Suggested deadline: 1 Dec 2010. Thanks Ian