Either monad transformer; profiling libraries

 This library provides a minimalist Either monad transformer, EitherT.
 EitherT is a version of ErrorT that does not require a spurious Error
 instance for the Left case.
 .
 This package provides a library for the Haskell programming language, compiled
 for profiling. See http://www.haskell.org/ for more information on Haskell.