Let's talk about Elixir

Introductory talk about Elixir, showcasing the core features and aims of the language.

Transcript

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

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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!
   

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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
   

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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
   

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

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

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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"
   

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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.
   

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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
   

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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.
    

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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.
    

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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
    

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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
    

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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
    

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

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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
    

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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.
    

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

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

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