My today’s view on code

This morning I have finished watching a course on Frontend Masters. It’s called “Hardcore Functional Programming in JavaScript.” Functional programming (FP) is interesting to me. It’s partly because I hear people speaking very passionately about it. It’s like an exotic thing that I don’t completely understand, but I’m curious to find out what it is.

A few months ago I have watched a Haskell course. Haskell seems to be the reference language when it comes to FP. Lisp is another reference FP language. And I have read the SICP introductory course that uses Scheme — a dialect of Lisp. Then I have read another book on Common Lisp. I still have a Lisp blog in my Feedly.

I found Haskell hard. Lisp felt more approachable. I liked the simplicity of Scheme. In SICP I have recognized things that I use in JS: dynamic typing, closures, lexical scope, and first-class functions. I guess because of these common features there are many FP libraries written in JS.

My curiosity grew even more when I heard Uncle Bob promoting Clojure. He explains that FP languages are becoming more relevant now because computers have more and more CPU cores. And because of that the ability to build programs that run on multiple cores is more important. He says that FP languages seem to fit better parallel work because they favor immutability.

I didn’t apply neither Haskell nor Lisp. But, after this last video course I think I understand better functors and monads. I also realize that the more I understand them, the less they are attractive. I think it’s because they introduce too many new concepts. Category Theory seems to be an important part of the FP and this intimidates me. It is too much conceptual overhead.

Understanding a domain and modeling its concepts in a programming language is already hard, and introducing another conceptual layer makes it even harder.

I like it when program components reflects domain concepts. I like it when I look into a piece of code and I see the domain.

For example, a domain can be website. It’s composed of pages. Pages are composed of forms, links, and other UI widgets. When the code reflects these concepts — page, form, link, widget — it’s easier to understand. And when it’s easier to understand, it’s easier to adapt and grow along with the business that it supports.

I guess there is value in immutability and type systems, and I do find some of the FP idioms to be practical. But it’s more valuable to be able to look at a codebase and see what it does and how it relates to the business that it was built for.