Book Image

Mastering Functional Programming

Book Image

Mastering Functional Programming

Overview of this book

Functional programming is a paradigm specifically designed to deal with the complexity of software development in large projects. It helps developers to keep track of the interdependencies in the code base and changes in its state in runtime. Mastering Functional Programming provides detailed coverage of how to apply the right abstractions to reduce code complexity, so that it is easy to read and understand. Complete with explanations of essential concepts, practical examples, and self-assessment questions, the book begins by covering the basics such as what lambdas are and how to write declarative code with the help of functions. It then moves on to concepts such as pure functions and type classes, the problems they aim to solve, and how to use them in real-world scenarios. You’ll also explore some of the more advanced patterns in the world of functional programming such as monad transformers and Tagless Final. In the concluding chapters, you’ll be introduced to the actor model, which you can implement in modern functional languages, and delve into parallel programming. By the end of the book, you will be able to apply the concepts of functional programming and object-oriented programming (OOP)in order to build robust applications.
Table of Contents (17 chapters)

A parallel solution with Akka

Before approaching the problem of parallelizing our crawler, let's discuss our strategy of how we are going to approach it.

Strategy

We are going to model our problem of creating the actors' system with a tree of actors. This is because the task itself naturally forms a tree.

We have already discussed how all the links and pages on the internet comprise a graph. However, we have also discussed, in our example, two things that are not desirable when processing and traversing this graph—cycles and repetitions of work. So, if we have visited a certain node, we are not going to visit it anymore.

This means that our graph becomes a tree on processing time. This means you cannot...