Functional Programming with Phunkie: Funky Parser Combinators

Phunkie is a library with functional structures for PHP. In this tutorial, Phunkie creator Marcello Duarte, head of training at Inviqa, explains how to create Parser combinators using the functional library. This post first appeared on the Inviqa blog, and was republished here with their permission.

Learning functional programming

Functional programming really matters. Pure functions (or functions with no side effect) are the perfect units of behaviour because we can rely on them to build larger and more complex systems. The greatness of functional programming relies on this power of composability.

That’s something I first came to believe back in the days of my licentiate degree on Computing for Management, during a semester in AI with Lisp. My course curriculum was mostly focused on C/C++, therefore I had to stay focused on where the skills demand was.

Thankfully, I’ve been able to reignite my love of studying functional programming here at Inviqa where we’re delivering more and more projects based on Scala, the general purpose programming language.

I’ve read "the red book" about three times (the Chiusano & Bjarnason one, not the Vaughn Vernon’s one). I took all the Martin Odersky’s Coursera courses, and I spent hours of my weekends watching videos and reading papers.

And I set myself a challenge: to do with functional programming what I did when I was learning TDD and created PHPSpec (a BDD testing and design tool for PHP developers) to help me learn; I decided to write my own functional programming dialect in PHP. And so Phunkie was born!

Now over to you. Learning functional programming means immersing yourself in a new paradigm, which can be challenging. It requires a totally different mindset for approaching problems.

So, by the time you can use functional programming to solve real-world problems, you’ll have spent hours grasping the new thinking or getting clued-up on the theory.

In this tutorial, my aim is to help fast-track your journey by going over my implementation of Hutton & Meijer’s Monadic Parser Combinators. Hopefully you will be able to see both the thinking and the usefulness of functional programming.

And, by using Phunkie, you can eliminate the need to learn Haskell to understand the topic. All you should need is some familiarity with PHP.

So let’s get started!

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by Marcello Duarte via SitePoint