Unix pipes are Applicative: http://www.haskell.org/ghc/docs/6.12.1/html/libraries/base/Control-Applicative.html http://www.haskell.org/ghc/docs/6.12.1/html/libr

Unix pipes are Applicative: http://www.haskell.org/ghc/docs/6.12.1/html/libraries/base/Control-Applicative.html http://www.haskell.org/ghc/docs/6.12.1/html/libraries/base/C... Applicative and Unix pipes cannot change their computation topology. >monads were invented for the sole purpose of giving haskell a programmable model for IO, that's it. Monads were known long before Haskell. They just used in Haskell for IO and for much more things.