It also allows you to invert the order of the calls so they are written in the order they occur. Instead of paint(sand(cut(measure(wood)))), you can write wood

It also allows you to invert the order of the calls so they are written in the order they occur. Instead of paint(sand(cut(measure(wood)))), you can write wood | measure | cut | sand | paint, which is easier to read, especially if it splits over multiple lines or has additional arguments: paint(sand(cut(measure(wood, 12), 40, :WZ), 220), :red) wood | measure(12) | cut(40, :WZ) | sand(220) | paint(:red) IIRC you can do that in Haskell as well, but I forget the name of the feature. Many OOP libraries have started to adopt a chained method call style similar to this, but it is nice to be able to do with any function.