The SitePoint PHP blog has posted a tutorial by Marcello Duarte showing you how to use functional programming in PHP with the help of the Phunkie library.
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.
[...] 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.
He starts off by defining two terms that will be used through out the code: parsers and combinators. He shares a code example of a combinator and then moves on to examples of primitive parsers and parser combinators. Each section includes the code you'll need to use (making use of Phunkie) to make the functional magic happen.