This document introduces functional programming concepts using the Elixir programming language. It summarizes that Elixir is a dynamic and functional language that runs on the Erlang VM and is designed for fault tolerance and distribution. It emphasizes immutable state, recursion over loops, and passing functions as first-class citizens. The document provides examples of communication between processes, static and dynamic typing in Elixir, and building fault-tolerant applications using supervisors. It encourages learning Elixir through patience and finding the right learning method.

1. Making Software. Better.
Simple solutions to big business problems.
a sip of elixir

2. About me
● Likes to solve problems that usually involves writing software
● Currently, helping customers of Equal Experts solve their software problems
● Twitter: @uttamkini
● Blog: https://medium.com/@uttamkini

3. What is functional programming anyway
● Declarative
● Immutable state
● Data is separate from functions (though functions can accept and operate on data)
● Functions are first class citizens (functions can be passed to and returned from other functions)
● Iteration is done using recursion (no for(i=0...) loops)

4. Functional programming is important !!
● Today, faster programs means utilizing multiple cores of a machine
● Because state is immutable, it becomes easier to write concurrent programs with functional programming
● Code is easy to read and reason about (once you get used to it)
● Easy to enforce correctness with type inference and checking

5. But, I don’t do functional programming !!

6. Are you sure ?
● Immutable objects have always been around in Java (remember the String class ?)
● Not using setters/changing an object once it is created is considered good practice
● Preferring composition over inheritance
● Lambdas in C# and now even in Java
● The stream api in Java 8 and Linq in C#
● Optionals in Java 8

7. But …..
● Since FP features are a bolt on to an OO language, writing functional code does not feel “natural”
● It is easy to go back to old habits of writing code with for loops and mutations
● It is nicer to learn a paradigm in a language that is designed for the paradigm

8. An elixir to get you started
● Is a dynamic and functional language
● Runs on the battle tested Erlang VM (Beam)
● Designed for distribution and fault tolerance
● Syntax inspired from Ruby
● Developer friendly tooling and ecosystem
● Can use Erlang libraries

9. Talk is cheap ….
Show me the
code !!

10. Communication in a stateless world

11. Static or Dynamic typing ?… a bit of both
● Dynamic by default
● The elixir compiler uses type inference where it can
● You can optionally add @spec directive for stronger type checks

12. Location transparency
● One Process can pass messages to another process in the same “OS process” or to a different process on
the same machine or a different machine in the cluster.
● The VM takes care of serializing/deserializing messages and calling the right process

13. Supervisors and Applications
● A supervisor is a process that monitors another process
● It restarts the process if it terminates (let it crash philosophy !)
● One process crashing does not bring the application down
● Applications are supervisors that can be configured to automatically start on process start up

14. Soar with the Phoenix
● Inspired by Ruby on Rails
● Focussed on developer productivity
● Can handle millions of connections at the same time
● Really performant (has micro second response times for regular workloads)
● Great support for web sockets that can used to build more interactive web apps

15. Closing thoughts
● Be patient when you learn something new, it takes time
● Learning a new language makes you a better programmer even in your current language
● You don’t have to learn everything all at once, everybody has a different pace of learning, so again be
patient
● If reading books doesn’t work, try videos or online courses (Every person has a different way of learning)
● If you enjoy what you are learning, the chances of dropping out go down

16. Thank You
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