Haskell QuickCheck2 using ByteString?

Question

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?

score 10 · Accepted Answer · answered Nov 13 '11 at 18:52

10

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.

answered Nov 13 '11 at 18:52

Tarrasch

6

Thanks. I'm afraid the latest API documentation hasn't helped me much. It is all mumbo-jumbo without some higher level context. A lot of other documentation is also out of date. Very curious for what is supposedly a very popular test package. – Nov 13 '11 at 19:32

1 Answers1