Monad Transformer - Definition

Definition

A monad transformer consists of:

  1. A type constructor t of kind (* -> *) -> * -> *
  2. Monad operations return and bind (or an equivalent formulation) for all t m where m is a monad, satisfying the monad laws
  3. An additional operation, lift :: m a -> t m a, satisfying the following laws: (the notation `bind` below indicates infix application):
    1. lift . return = return
    2. lift (m `bind` k) = (lift m) `bind` (lift . k)

Read more about this topic:  Monad Transformer

Famous quotes containing the word definition:

    “Perhaps the best definition of progress would be the continuing efforts of men and women to narrow the gap between the convenience of the powers that be and the unwritten charter.”
    —Nadine Gordimer (b. 1923)

    “... we all know the wag’s definition of a philanthropist: a man whose charity increases directly as the square of the distance.”
    —George Eliot [Mary Ann (or Marian)

    “One definition of man is “an intelligence served by organs.””
    —Ralph Waldo Emerson (1803–1882)