slackbuilds/haskell/haskell-data-default-instances-base/README

This Haskell module defines Default instances for the types Int,
Int8, Int16, Int32, Int64, Word, Word8, Word16, Word32, Word64,
Integer, Float, Double, Ratio, Complex, '(->)', IO, Maybe, '()',
'[]', Ordering, Any, All, Last, First, Sum, Product, Endo, Dual,
and tuples.

After uninstalling, run this command to unregister the package from
the ghc package database:   ghc-pkg recache