Про Elixir. Станислав Мехоношин

Видео: https://www.youtube.com/watch?v=_dFFUO_Du0Y

Transcript

1. Про.Elixir
   Серия докладов: “Чем заняться вместо работы?”
   

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2. Stas Mekhonoshin
   Toptal.com
   github.com/Mehonoshin
   blog.cspub.net
   

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3. Откуда хайп?
   

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4. Jose Valim
   

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6. Руби-программисты
   

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7. Что это такое?
   

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8. First class functions
   Modules
   BEAM
   Pattern Matching
   Actors
   OTP
   Erlang && Elixir
   

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9. Functions && Modules
   defmodule ExBees.Map.SegmentsSupervisor do
   use Supervisor
   def start_link(name) do
   Supervisor.start_link(__MODULE__, :ok, name: name)
   End
   def init(:ok) do
   children = [
   supervisor(ExBees.Map.Segment, [ExBees.Map.Segment])
   ]
   supervise(children, strategy: :one_for_one)
   end
   end
   

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10. BEAM
    Lightweight processes
    Soft-realtime
    Full CPU utilization
    

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11. Pattern Matching
    iex> {a, b, c} = {:hello, "world", 42}
    {:hello, "world", 42}
    iex> a
    :hello
    iex> b
    "world"
    

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12. Pattern Matching 2
    iex> case {1, 2, 3} do
    ...> {4, 5, 6} ->
    ...> "This clause won't match"
    ...> {1, x, 3} ->
    ...> "This clause will match and bind x to 2 in this clause"
    ...> _ ->
    ...> "This clause would match any value"
    ...> end
    "This clause will match and bind x to 2 in this clause"
    

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13. Actors
    current_process = self()
    # Spawn an Elixir process (not an operating system one!)
    spawn_link(fn ->
    send current_process, {:msg, "hello world"}
    end)
    # Block until the message is received
    receive do
    {:msg, contents} -> IO.puts contents
    end
    

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14. Actors 2
    No shared memory
    GC per process
    

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15. OTP
    

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16. Блог на OTP
    

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17. Distributed
    Multi-Core
    Connections
    Fault-tolerant
    ДЛЯ ВАШЕГО БЛОГА
    Usecases
    

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18. VS
    

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19. Синтаксис
    -module(hello_module).
    -export([some_fun/0, some_fun/1]).
    % A "Hello world" function
    some_fun() ->
    io:format('~s~n', ['Hello world!']).
    % This one works only with lists
    some_fun(List) when is_list(List) ->
    io:format('~s~n', List).
    % Non-exported functions are private
    priv() ->
    secret_info.
    defmodule HelloModule do
    # A "Hello world" function
    def some_fun do
    IO.puts "Hello world!"
    end
    # This one works only with lists
    def some_fun(list) when is_list(list) do
    IO.inspect list
    end
    # A private function
    defp priv do
    :secret_info
    end
    end
    

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20. 0 : 1
    

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21. Экосистема
    Rebar Mix tool
    Hex.pm
    GenStage
    Phoenix Framework
    Plug
    

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22. 0 : 2
    

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23. Метапрограммирование
    defmodule MyValidator do
    use Validator
    validate_length :name, 1..100
    validate_matches :email, ~r/@/
    end
    MyValidator.validate(user)
    

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24. 0 : 3
    

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25. Мутабельность переменных
    ~ erl
    Eshell V8.2 (abort with ^G)
    1> A = 1.
    1
    2> A = 2.
    ** exception error: no match of
    right hand side value 2
    3> io:format("~p", [A]).
    1ok
    ~ iex
    Interactive Elixir (1.4.1) - press
    Ctrl+C to exit (type h() ENTER for
    help)
    iex(1)> a = 1
    1
    iex(2)> a = 2
    2
    iex(3)> IO.puts a
    2
    :ok
    

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26. 1 : 3
    

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27. Признание геями хипстерами
    НЕТ ДА
    

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28. ELIXIR WINS
    

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29. Коммьюнити
    Модное
    Стильное
    Очень активное
    Новые инструменты
    Простор для opensource
    

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30. "Разбудите меня лет через
    сто, и спросите, что
    сейчас делается на
    Гитхабе. И я отвечу —
    переписывают блоги с Ruby
    на Elixir."
    Михаил Салтыков-
    Щедрин 1826-1889
    

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31. The End
    

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