Parsec is designed from scratch as an industrial-strength parser
library.  It is simple, safe, well documented, has extensive
libraries and good error messages, and is also fast.  It is defined
as a monad transformer that can be stacked on arbitrary monads, and
it is also parametric in the input stream type.

This requires ghc, haskell-transformers, haskell-mtl, haskell-deepseq,
and haskell-text.

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