Merge pull request #9 from csabahruska/patch-1

add: Recursion Schemes, Part IV: Time is of the Essence

Author: passy

README.md

@@ -40,6 +40,7 @@ Recursion schemes are simple, composable combinators, that automate the process
 - [Rotating Squares](https://jtobin.io/rotating-squares) - Using a hylomorphism to rotate a quadtree by Jared Tobin.
 - [Promorphisms, Pre and Post](https://jtobin.io/promorphisms-pre-post) - Pratical examples of pre- and postpromorphisms by Jared Tobin.
 - [Time Traveling Recursion Schemes](https://jtobin.io/time-traveling-recursion) - Exploring histo and futu by example by Jared Tobin.
+- [Recursion Schemes, Part IV: Time is of the Essence](http://blog.sumtypeofway.com/recursion-schemes-part-iv-time-is-of-the-essence/) - Practical article about histomorphism and the futumorphism.
 - [Cheat Sheet](https://github.com/sellout/recursion-scheme-talk/blob/master/cheat%20sheet.pdf) - Map of various recursion schemes and their duals.
 - [Correcting the Visitor pattern](http://logji.blogspot.co.uk/2012/02/correcting-visitor-pattern.html) - Showing that the Visitor pattern implements an f-algebra for use with a catamorphism (in Java).