[Haskell-cafe] Implementation of scaled integers

Hi all, is there a library for Haskell that implements scaled integers, i.e. integers with a fixed scale factor so that the scale factor does not need to be stored, but is part of the type? In particular it would be useful (i.e. for signal processing) to have numbers based on Int scaled such that they fall into the range [-1.0 .. 1.0). Or other scale factors which are powers of 2. Addition and subtraction would then map to the ordinary operations for Int, while Multiplication and Division would have to apply the scale factor to correct the result of normal Int operations (which would be a shift operation). If it doesn't exist yet, have you got ideas how to implement that for maximum efficiency? Cheers Stefan