Introductory talk about Elixir, showcasing the core features and aims of the language. Originally presented by Dimitris Zorbas at the 26th Athens Ruby Meetup, hosted by Skroutz.

1. Let’s Talk About
Dimitris Zorbas - Athens Ruby Meetup#26
github.com/zorbash @_zorbash

2. is a functional, concurrent language designed for
building scalable and maintainable applications.
Dimitris Zorbas - Athens Ruby Meetup#26
The power of Erlang meets the joy of Ruby!

3. Why Bother?
➔ Created by a rubyist
aimed to rubyists
➔ Learn a new language
every year
➔ Even Matz likes it!
Dimitris Zorbas - Athens Ruby Meetup#26

4. Really Why Bother?
Seems to solve the core issues of Ruby
(performance / scalability / maintainability),
adopting a functional programming model, with a
sweet Ruby-like syntax and cherries on top.
Dimitris Zorbas - Athens Ruby Meetup#26

5. Really Why Bother?
Dimitris Zorbas - Athens Ruby Meetup#26

6. Features
Immutability
Dimitris Zorbas - Athens Ruby Meetup#26
will_change = 42
answer = fn -> will_change end
will_change = 1337
answer.()
# => 42

7. Features
Pipelines
Dimitris Zorbas - Athens Ruby Meetup#26
[42, nil, 1337, nil, 4]
|> Enum.filter(&(&1))
|> Enum.map(&(&1 * 2))
|> Enum.sort
|> Enum.join(", ")
# => "84, 2674, 8"

8. Features
Pattern-Matching
Dimitris Zorbas - Athens Ruby Meetup#26
Pattern matching is one of the cornerstones of an equational style of
definition; more often than not it leads to a cleaner and more readily
understandable definition than a style based on conditional
equations. It also simplifies the process of reasoning formally about
functions.

9. Features
Pattern-Matching
Dimitris Zorbas - Athens Ruby Meetup#26
defmodule Speaker do
def talk(:bob), do: "Hi, uncle Bob!"
def talk(42), do: "Oh! the answer to life the universe and everything"
def talk(n) when is_number(n), do: "You're an ordinary number"
def talk(_), do: "I don't really know what to tell you"
end

10. Concurrency: Actor Model
Features
Dimitris Zorbas - Athens Ruby Meetup#26
Processes (actors) are the center of computation and have mailboxes.
They communicate by sending asynchronous messages to each other.

11. Concurrency: Actor Model
Features
Dimitris Zorbas - Athens Ruby Meetup#26
OOP to me means only messaging, local retention and protection and
hiding of state-process and extreme late-binding of all things.

12. Dimitris Zorbas - Athens Ruby Meetup#26
defmodule Speaker do
import IO, only: [puts: 1]
def new, do: spawn &start/0
def start do
receive do
{:answer, name} -> puts talk(name)
_ -> puts "I don't know how to handle that"
after
2000 -> puts "[#{inspect(self)}] Tell me something to do"
end
start
end
def talk(:bob), do: "Hi, uncle Bob!"
def talk(42), do: "Oh! the answer to life the universe and everything"
def talk(n) when is_number(n), do: "You're an ordinary number"
def talk(_), do: "I don't really know what to tell you"
end

13. Features
Async Tests
defmodule SpeakerTest do
use ExUnit.Case, async: true # Examples run concurrently
test "talking to bob" do
assert Speaker.talk(:bob) == "Hi, uncle Bob!"
End
test "talking to a stranger" do
assert Speaker.talk(:voldemort) == "I don't really know what to tell you"
end
end
Dimitris Zorbas - Athens Ruby Meetup#26

14. Erlang Interoperability
Features
Dimitris Zorbas - Athens Ruby Meetup#26
Erlang / LFE (Lisp-Flavored-Erlang) / Elixir all run on BEAM
OTP is directly available in Elixir

15. Live Fast, Die Young
Philosophy
Dimitris Zorbas - Athens Ruby Meetup#26

16. Live Fast, Die Young
Philosophy
Dimitris Zorbas - Athens Ruby Meetup#26
● Failures are embraced and managed. Let it crash!
● Failure is isolated in process level. No exceptions.
● Failing fast is revealing. The system stays up.
● Write Offensive Code

17. Live Fast, Die Young
Philosophy
Dimitris Zorbas - Athens Ruby Meetup#26
The world is concurrent. Things in the world don't share data.
Things communicate with messages. Things fail.

18. Resources
Dimitris Zorbas - Athens Ruby Meetup#26
● http://elixir-lang.org/getting-started/introduction.html
● http://elixirplayground.com/
● https://elixir-lang.slack.com/

19. you |> ask :questions |> Enum.any?