Let's create stateful systems, by Elixir

Transcript

1. Let's create stateful
   systems, by Elixir
   

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2. .
   ｡oO(
   さっちゃんですよヾ(
   〃l _ l)
   ﾉﾞ☆)
   

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3. I'll show you a number.
   

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5. Two
   

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6. Ⅱ
   

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7. ⼆
   

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8. 2 is a number of collison & collaboration.
   

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9. I & you
   hot & ice
   stand up & lie down
   inside & outside
   

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10. stateless & stateful
    

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11. Function is stateless. f : x -> y
    e.g. Web server
    

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12. Dialogue is stateful.
    Alice : X.
    Bob : Y.
    Alice : X.
    Bob : Z.
    Most of the system is stateful.
    

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13. Elixir
    

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14. Elixir is a functional programming language.
    Functional programming is stateless.
    All data of Elixir is immutable.
    [x, 3, x] = Enum.map([1,2,1], &(&1 + 1))
    assert 2 == x
    // Many lines that don't reassign to `x`.
    assert 2 == x
    

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15. Elixir has processes.
    29 =
    Task.async(fn -> 29 end)
    |> Task.await
    

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16. Process has state.
    agent = Agent.start_link(fn -> 29 end)
    29 = Agent.get(agent, &(&1))
    Agent.update(agent, &(&1 + 13))
    42 = Agent.get(agent, &(&1))
    

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17. State should be updated in a transaction.
    State shold interact & isolate each other.
    Accessing to state should be scaled in-out.
    Server with state should be updated gracefully.
    Elixir has all of these!
    

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18. State should be updated in a transaction. (No shared
    state)
    State shold interact & isolate each other. (Application,
    Supervisor)
    Accessing to state should be scaled in-out. (GenStage,
    Task, Register, Erlang cluster)
    Server with state should be updated gracefully. (Hot
    code swap)
    

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19. We can create stateful system easy, by constructing
    stateless parts.
    

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20. How we can start Elixir?
    Let's create some applications.
    * Web application with Phoenix.
    * Slack bot.
    

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21. Phoenix is a Web application framework that familiar
    with WebSocket.
    https://hexdocs.pm/phoenix/overview.html
    

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22. React is available (✿
    >ヮ ╹
    )-♡
    Let's create a realtime interaction ∩
    (＞ ◡
    ＜*)∩
    ♡
    https://speakerdeck.com/ne_sachirou/phoenix-livereact
    

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23. Create a Slack bot.
    https://github.com/BlakeWilliams/Elixir-Slack
    (Easy, so no topic.)
    

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24. Installing Elixir.
    asdf https://asdf-vm.com/
    asdf plugin-add erlang
    asdf install erlang 22.0.7
    asdf plugin-add elixir
    asdf install elixir 1.9.1
    

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25. Text editor?
    VSCode with mjmcloug.vscode-elixir
    works.
    

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26. Format & lint.
    InnerCotton https://github.com/ne-sachirou/inner_cotton is a set
    of standard development tools.
    mix cotton.init
    mix cotton.lint --fix
    

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27. Docker image (You need Docker :-)
    Fix major ver.s both Erlang & Elixir.
    docker run -it --rm nesachirou/elixir:1.9_erl22
    

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28. Textbook & document.
    Official guide : https://elixir-lang.org/
    Official document : https://hexdocs.pm/elixir/Kernel.html
    Online textbook : https://elixirschool.com/ja/
    Textbook : https://tatsu-zine.com/books/programming-elixir-ja
    

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29. https://speakerdeck.com/ne_sachirou/elixirwan-quan-nili-jie-sita
    

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30. Advanced resources
    

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31. Erlang in Anger
    https://ymotongpoo.github.io/erlang-in-anger/text-ja.pdf
    You want to read this… before production.
    

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32. https://speakerdeck.com/ne_sachirou/sutetohurudeda-gui-mo-
    akusesufalsearusoft-realtimenagemusabawoeasynitukuru
    

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33. https://speakerdeck.com/ne_sachirou/elixir-on-containers
    

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34. https://speakerdeck.com/ne_sachirou/phoenix-at-scale
    

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35. https://speakerdeck.com/ne_sachirou/ddd-data-driven-development
    

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