Haskell import declaration

Question

I started to read about monad transformers and what puzzles me is Control.Monad.CatchIO's import declaration which I see in many code examples:

import "MonadCatchIO-transformers" Control.Monad.CatchIO (finally)

What does this quoted token mean? I took a look at the Haskell 98 Report's section on import declarations, but this didn't help me understand.

Answer 1

Its a package-qualified import, which is a GHC extension. The string is a package name.

See Package-qualified imports, from the ghc docs, for details.