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haskellquickcheck

Haskell QuickCheck2 using ByteString?

The RWH books says that to get ByteString support, I need to add:

instance Arbitrary B.ByteString where
    arbitrary   = fmap B.pack arbitrary
    coarbitrary = coarbitrary . B.unpack

But my GHC 7.2 with QuickCheck 2.4.1.1 tells me:

`coarbitrary' is not a (visible) method of class `Arbitrary'

Any pointers?

Solution

  • coarbitrary has moved to it's own typeclass CoAbritary in QC 2.0, so simply just remove the equation for coarbitrary.

    Also see the latest documentation.