In Haskell, it makes no sense, agreed. In C++, it makes sense: http://www.sgi.com/tech/stl/functors.html http://www.sgi.com/tech/stl/functors.html. Functors ar

In Haskell, it makes no sense, agreed. In C++, it makes sense: http://www.sgi.com/tech/stl/functors.html http://www.sgi.com/tech/stl/functors.html. Functors are function objects, which is to say they're a class/struct with one method, operator(). If this makes you sigh, know that you're not alone.