Book Image

Learning Elixir

By : Kenny Ballou, Kenneth Ballou
Book Image

Learning Elixir

By: Kenny Ballou, Kenneth Ballou

Overview of this book

Elixir, based on Erlang’s virtual machine and ecosystem, makes it easier to achieve scalability, concurrency, fault tolerance, and high availability goals that are pursued by developers using any programming language or programming paradigm. Elixir is a modern programming language that utilizes the benefits offered by Erlang VM without really incorporating the complex syntaxes of Erlang. Learning to program using Elixir will teach many things that are very beneficial to programming as a craft, even if at the end of the day, the programmer isn't using Elixir. This book will teach you concepts and principles important to any complex, scalable, and resilient application. Mostly, applications are historically difficult to reason about, but using the concepts in this book, they will become easy and enjoyable. It will teach you the functional programing ropes, to enable them to create better and more scalable applications, and you will explore how Elixir can help you achieve new programming heights. You will also glean a firm understanding of basics of OTP and the available generic, provided functionality for creating resilient complex systems. Furthermore, you will learn the basics of metaprogramming: modifying and extending Elixir to suite your needs.
Table of Contents (16 chapters)
Learning Elixir
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Exception handling


You may be familiar with the concept of exceptions from other languages. Thus, you may be tempted to think of them similarly when coming to Elixir. However, like many things we have covered so far, and many things we will cover, we need to forget most what we have learned when learning most concepts of functional programming and Elixir.

Elixir offers some basic facilities for raising and catching exceptions.

First and foremost, exceptions in Elixir are not control flow or branching structures. Exceptions are meant strictly for exceptional behaviour, that is, things that should absolutely not happen is happening. Some examples of exceptions are database servers going down, name servers failing, or attempting to open a fixed location configuration file. However, failing to open a file whose name is given by a user is not an exception; this is entirely something we can, as programmers, anticipate failing.

This boils down to the assumptions made about a system when it is programmed...