libghc-managed-dev binary package in Ubuntu Lunar amd64

 In Haskell you very often acquire values using the with...
 idiom using functions of type (a -> IO r) -> IO r. This idiom forms a
 Monad, which is a special case of the ContT monad (from transformers) or
 the Codensity monad (from kan-extensions). The main purpose behind this
 package is to provide a restricted form of these monads specialized to this
 unusually common case.
 .
 The reason this package defines a specialized version of these types
 is to:
 .
  * be more beginner-friendly,
  * simplify inferred types and error messages, and:
  * provide some additional type class instances that would otherwise
    be orphan instances
 .
 This package provides a library for the Haskell programming language.
 See http://www.haskell.org/ for more information on Haskell.

Source package