J. David Eisenberg 
Web Development with ReasonML [PDF ebook] 
Type-Safe, Functional Programming for JavaScript Developers

Reason ML is a new, type-safe, functional language that compiles to efficient, readable Java Script. Reason ML interoperates with existing Java Script libraries and works especially well with React, one of the most popular front-end frameworks. Learn how to take advantage of the power of a functional language while keeping the flexibility of the whole Java Script ecosystem. Move beyond theory and get things done faster and more reliably with Reason ML today.Reason ML is a new syntax for OCaml, a battle-tested programming language used in industry for over 20 years. Designed to be familiar to Java Script programmers, Reason ML code compiles to highly readable Java Script. With Reason ML, you get OCaml’s powerful functional programming features: a strong static type system with an excellent type inference engine, pattern matching, and features for functional programming with immutable variables. Reason ML also allows flexibility with opt-in side effects, mutation, and object-oriented programming. Reason ML hits the sweet spot between the pure theoretical world and the laissez-faire approach of Java Script.Start using Reason ML’s powerful type system as you learn the essentials of the language: variables and arithmetic operations. Gain expressive power as you write functions with named parameters and currying. Define your own data types, and integrate all these capabilities into a simple web page. Take advantage of Reason ML’s functional data structures with map and reduce functions. Discover new ways to write algorithms with Reason ML’s recursion support. Interoperate with existing Java Script libraries with bindings, and write reactive web applications using Reason ML in tandem with React. Reinforce concepts with examples that range from short, tightly focused functions to complete programs, and practice your new skills with exercises in each chapter.With Reason ML, harness the awesome power of a functional language while retaining the best features of Java Script to produce concise, fast, type-safe programs.What You Need:You’ll need to have node.js (version 10.0 or above) and npm (version 5.6 or above). Once you install the bs-platform package and fire up a text editor, you’re ready to go. (There are plugins for many popular editors that will make editing easier.)