functors

Scott Wlaschin demystifies functional programming terms like monads, monoids, functors and catamorphisms by showing how they fit into a small toolkit. He applies them to problems such as missing data, list handling, and functional dependency injection.

An episode of FunFunFunction explaining monads in JavaScript as functors that also implement flatMap. It builds on the preceding functor episode and works through code examples.

Tsoding live-codes a JSON parser from scratch in Haskell in about 111 lines, using only the standard library. It is an edited Twitch stream that explains the intuition behind parser combinators, functors, applicatives and monads.