Functors, Applicatives, and Monads

Hello! Today, we will explore functional programming with the concepts of functors, applicatives, and monads. We will discuss what they are and why they matter one step at a time. Note that all the examples will be in Haskell, but you’re not required to know Haskell to read this post. I’ve also added a section at the end following a pretty disappointing interaction with someone associated with the Haskell foundation. Functors This is a closed box: Of course, as with every closed box, you can’t really know what’s inside unless you open it, right? So let’s open it, and… surprise! The box contains the answer to the Ultimate Question of Life, The Universe, and Everything: Now, let’s translate the box analogy into programming. A box can be any data structure surrounded by a context. Said differently, a wrapper or container type that adds additional information or behavior to the underlying data. In this example, we will say that blue boxes represent the possibility of an optional valu ... Read full article.