This reply is a little late, but there is a series on the (non-free-but-worth-it-for-one month) "Frontend Masters" site. It is called Hardcore Functional Progra

This reply is a little late, but there is a series on the (non-free-but-worth-it-for-one month) "Frontend Masters" site. It is called Hardcore Functional Programming (or similar) and goes into Monads, Functors in normal JavaScript.