Learn ElixirManchester Lambda Lounge, Monday 20 Feb 2017, 7pm

Presented by Chi-chi Ekweozor @thisischichi

“Elixir is a dynamic, functional language with Ruby-like syntax that runs on the Erlang virtual machine. It can be described as the language

for the modern, real time, hyper-connected world with first class support for concurrency,

fault tolerance and high availability, all courtesy of its Erlang pedigree.”

• Elixir is a functional language. There are two things to remember:

Immutable data: any function that transforms data will return a new copy of it

We can combine functions, and run them in parallel if we please, using lightweight Elixir ‘processes’

Learn Elixir

• Install Elixir

• What is pattern matching?

• Meet Lists, and Modules

• Meet the Pipe Operator |>

• Resources for learning

Install Elixir

To install Elixir on your computer, follow the instructions at:

http://elixir-lang.org/install.html

iex - Interactive Elixir

To test your Elixir installation was successful, start an Elixir session. At your regular shell prompt, type iex.

Elixir Basics

Learn Elixir

• Install Elixir

• What is pattern matching?

• Meet Lists, and Modules

• Meet the Pipe Operator |>

• Resources for learning

Pattern matching?

Type this into your terminal: iex> a = 1 iex> a + 3

Now, type this into your terminal: iex> a = 1 iex> 1 = a iex> 2 = a

Lists, and pattern matching: iex> list = [ 1, 2, 3 ] iex> [ a, b, c ] = list

iex> a, iex> b, etc etc

More lists: iex> list = [ 1, 2, 3 ] iex> [ a, 2, b ] = list

iex> a, iex> b, etc etc

There’s more to this than might be immediately apparent:

iex> list = [ 1, 2, 3 ] iex> [ a, 1, b ] = list

Learn Elixir

• Install Elixir

• What is pattern matching?

• Meet Lists, and Modules

• Meet the Pipe Operator |>

• Resources for learning

Now meet Modules

clause

Learn Elixir

• Install Elixir

• What is pattern matching?

• Meet Lists, and Modules

• Meet the Pipe Operator |>

• Resources for learning

The Pipe Operator |>

We’ve all seen code like this:

people = DB.find_customers

orders = Orders.for_customers(people)

tax = sales_tax(orders, 2016)

filing = prepare_filing(tax)

The alternative was to write:

filing = prepare_filing(sales_tax(Orders.for_customers(DB.find_customers), 2016))

Elixir has a better way of writing it…

The Pipe or Pipeline Operator |> takes the result of the previous

expression and feeds it to the next one as the first argument

In Elixir, the awkward to read function becomes:

filing = DB.find_customers

|> Orders.for_customers

|> sales_tax(2016)

|> prepare_filing

Putting it all together, a |> exercise:

Learn Elixir

• Install Elixir

• What is pattern matching?

• Meet Lists, and Modules

• Meet the Pipe Operator |>

• Resources for learning

Learning Resources

Books:

Programming Elixir 1.3 by Dave Thomas

Elixir in Action by Saša Jurić

Websites:

elixir-lang.org

elixirforum.com

elixirschool.com