Monad

In Functional Programming, a monad is a structure that represents computations defined as sequences of steps. A type with a monad structure defines what it means to chain operations, or nest functions of that type together. This allows the programmer to build PipeLine-s that process data in steps, in which each action is decorated with additional processing rules provided by the monad. http://en.wikipedia.org/wiki/Monad_(functional_programming)

http://foldoc.org/monad

Wiki Wiki Web:MonadicProgramming

Wiki Wiki Web:OnMonads

in Python http://www.dustingetz.com/2012/10/07/monads-in-python-identity-maybe-error.html