A short introduction to Elixir presented by Chi-chi Ekweozor at Manchester UK's MadLab on 20 February. Learn how to use the ubiquitous pipeline operator |> to consume functions as data, pattern matching, modules, lists and other language constructs.

1. Learn Elixir
Manchester Lambda Lounge, Monday 20 Feb 2017, 7pm
Presented by Chi-chi Ekweozor
@thisischichi

2. “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.”

3. • 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’

4. Learn Elixir
• Install Elixir
• What is pattern matching?
• Meet Lists, and Modules
• Meet the Pipe Operator |>
• Resources for learning

5. Install Elixir

6. To install Elixir on your computer, follow the
instructions at:
http://elixir-lang.org/install.html

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

8. Elixir Basics

9. Learn Elixir
• Install Elixir
• What is pattern matching?
• Meet Lists, and Modules
• Meet the Pipe Operator |>
• Resources for learning

10. Pattern matching?

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

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

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

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

15. There’s more to this than might be
immediately apparent:
iex> list = [ 1, 2, 3 ]
iex> [ a, 1, b ] = list

16. Learn Elixir
• Install Elixir
• What is pattern matching?
• Meet Lists, and Modules
• Meet the Pipe Operator |>
• Resources for learning

17. Now meet Modules

22. clause

25. Learn Elixir
• Install Elixir
• What is pattern matching?
• Meet Lists, and Modules
• Meet the Pipe Operator |>
• Resources for learning

26. The Pipe Operator |>

27. 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)

28. The alternative was to write:
filing = prepare_filing(sales_tax(Orders.for_customers(DB.find_customers),
2016))

29. Elixir has a better way of writing it…

30. The Pipe or Pipeline Operator |>
takes the result of the previous
expression and feeds it to the next
one as the first argument

31. In Elixir, the awkward to read function becomes:

32. filing = DB.find_customers
|> Orders.for_customers
|> sales_tax(2016)
|> prepare_filing

33. Putting it all together, a |> exercise:

35. Learn Elixir
• Install Elixir
• What is pattern matching?
• Meet Lists, and Modules
• Meet the Pipe Operator |>
• Resources for learning

36. Learning Resources

37. Books:
Programming Elixir 1.3 by Dave Thomas
Elixir in Action by Saša Jurić
Websites:
elixir-lang.org
elixirforum.com
elixirschool.com