Book excerpt: Functional-Light JavaScript is a balanced, pragmatic exploration of Functional Programming in JavaScript.Functional Programming (FP) is an incredibly powerful paradigm for structuring code that yields more robust, verifiable, and readable programs. If you've ever tried to learn FP but struggled with terms like "monad", mathematical concepts like category theory, or symbols like (lambda), you're not alone.Functional-Light programming distills the most vital aspects of FP-function purity, value immutability, composition, and more!-down to approachable JavaScript patterns. Rather than the all-or-nothing dogmatism often encountered in FP, this book teaches you how to improve your programs line by line.