Clojure is a general purpose programming language designed for the fast-approaching future.
It's common that adding more layers of abstraction or indirection will make things slower. However, React and ClojureScript make web pages faster than doing it by hand -- essentially programming the bare web. The lesson is that if you choose your layers well, they can actually make your system faster.
Functional programmers often use the term "reason about code". It's not very well defined generally, but I use it myself to refer to our ability to use our real-world intuition in our own code.
Immutable data appear to contradict our observations of the real world. Things in the world are mutable, so shouldn't our data be mutable, too? It may be counterintuitive, but immutable data does a better job of modeling many of our expectations of the real world.
Composition is an important idea in programming, and Functional Programming brings it to the forefront. But what does it mean to say things are composable?
There are many classics of functional programming that can help you take your thinking to the next level. My recommendations are for making you think in a new way.
Global mutable state is one of the biggest drivers of complexity in software systems. We tackle a definition and how to reduce our reliance on it.
Functional programming, from one perspective, is just a collection of habits that affect our programming. I've identified the cues for those habits and a routine for replacing imperative code with functional code.
If you're a Rubyist and you've heard some buzz about Clojure, these videos and links will be just for you. Rubyists teaching Clojure, Clojurists introducing Clojure to Ruby programmers, and Rubyists pontificating on Clojure.
Professional Clojure programmers rely on certain features of their editors to help them program. When choosing an editor, it's important to pick one that has these two important features: REPL integration and structural editing.