-- Useful when there is a signature with multiple names, e.g.
--   foo, bar :: Types..
-- but only one of the names is exported and we have to change the
-- type signature to only include the exported names.
filterLSigNames :: (name -> Bool) -> LSig name -> Maybe (LSig name)
filterLSigNames p (L loc sig) = L loc <$> (filterSigNames p sig)
filterLSigNames :: (name -> Bool) -> LSig name -> Maybe (LSig name)
filterLSigNames p (L loc sig) = L loc <$> (filterSigNames p sig)
filterLSigNames p (L loc sig) = L loc <$> (filterSigNames p sig)