How do you adopt functional design patterns?

1 Learn the basics

Before you dive into functional design patterns, you need to have a solid grasp of the core concepts and principles of functional programming, such as referential transparency, side effects, recursion, currying, lambda expressions, and monads. You can learn these concepts from books, courses, or tutorials that cover functional programming in your preferred language, such as Haskell, Scala, Clojure, or JavaScript.

2 Identify the problem

Once you have a good understanding of functional programming, you can start applying functional design patterns to solve specific problems in your code. The first step is to identify the problem you want to solve, such as how to handle errors, how to manage state, how to compose functions, or how to implement concurrency. You can use a problem-solving framework, such as the SICP method, to analyze the problem and break it down into smaller subproblems.

3 Choose the pattern

After you have defined the problem, you can look for a functional design pattern that matches your needs and goals. You can use a catalog of functional design patterns, such as the one by Scott Wlaschin, to browse through different categories and examples of patterns, such as functors, applicatives, monoids, decorators, or strategies. You can also use a comparison table, such as the one by Mario Fusco, to see how different patterns relate to each other and how they differ from object-oriented design patterns.

4 Implement the pattern

Once you have selected the functional design pattern that suits your problem, you can implement it in your code. You can use a template, such as the one by Gabriel Volpe, to follow the structure and syntax of the pattern in your language. You can also use a library, such as Cats or Scalaz for Scala, or Ramda or Lodash for JavaScript, to leverage existing implementations of functional design patterns and avoid reinventing the wheel.

5 Test and refactor

The final step is to test and refactor your code to ensure that it works correctly and follows the best practices of functional programming. You can use a testing framework, such as QuickCheck or ScalaCheck, to generate random inputs and check the properties and behavior of your functions. You can also use a refactoring tool, such as IntelliJ IDEA or VS Code, to apply common refactorings, such as extracting or inlining functions, renaming variables, or simplifying expressions.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?