slackbuilds/haskell/haskell-mono-traversable/README

Type classes for mapping, folding, and traversing monomorphic and
polymorphic containers. Haskell is good at operating over polymorphic
containers such as a list [a]. A monomorphic container is one such
as Text which has a type Text that does not expose a type variable
for the underlying characters.

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