The document is an overview of a presentation about learning Elixir, a functional programming language with a syntax similar to Ruby, scheduled for February 20, 2017. Key topics include installation, pattern matching, working with lists and modules, and using the pipe operator for cleaner code. Additional resources for learning Elixir are also provided, including recommended books and websites.

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