Here's a good talk from Rich Hickey about the underpinnings, mechanisms, and rationale behind reducers: http://www.infoq.com/presentations/Clojure-Reducers http

Here's a good talk from Rich Hickey about the underpinnings, mechanisms, and rationale behind reducers: http://www.infoq.com/presentations/Clojure-Reducers http://www.infoq.com/presentations/Clojure-Reducers. I highly recommend it. As he says, it's based off of some concepts from Enumerator/Iteratee, which AIUI originated or was explored initially in the Haskell space: http://www.haskell.org/haskellwiki/Enumerator_and_iteratee http://www.haskell.org/haskellwiki/Enumerator_and_iteratee. I found Hickey's presentation a lot easier to understand.