Slide 1
Slide 1 text
Let's create stateful
systems, by Elixir
Slide 2
Slide 2 text
.
｡oO(
さっちゃんですよヾ(
〃l _ l)
ﾉﾞ☆)
Slide 3
Slide 3 text
I'll show you a number.
Slide 4
Slide 4 text
2
Slide 5
Slide 5 text
Two
Slide 6
Slide 6 text
Ⅱ
Slide 7
Slide 7 text
⼆
Slide 8
Slide 8 text
2 is a number of collison & collaboration.
Slide 9
Slide 9 text
I & you
hot & ice
stand up & lie down
inside & outside
Slide 10
Slide 10 text
stateless & stateful
Slide 11
Slide 11 text
Function is stateless. f : x -> y
e.g. Web server
Slide 12
Slide 12 text
Dialogue is stateful.
Alice : X.
Bob : Y.
Alice : X.
Bob : Z.
Most of the system is stateful.
Slide 13
Slide 13 text
Elixir
Slide 14
Slide 14 text
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
Slide 15
Slide 15 text
Elixir has processes.
29 =
Task.async(fn -> 29 end)
|> Task.await
Slide 16
Slide 16 text
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))
Slide 17
Slide 17 text
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!
Slide 18
Slide 18 text
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)
Slide 19
Slide 19 text
We can create stateful system easy, by constructing
stateless parts.
Slide 20
Slide 20 text
How we can start Elixir?
Let's create some applications.
* Web application with Phoenix.
* Slack bot.
Slide 21
Slide 21 text
Phoenix is a Web application framework that familiar
with WebSocket.
https://hexdocs.pm/phoenix/overview.html
Slide 22
Slide 22 text
React is available (✿
>ヮ ╹
)-♡
Let's create a realtime interaction ∩
(＞ ◡
＜*)∩
♡
https://speakerdeck.com/ne_sachirou/phoenix-livereact
Slide 23
Slide 23 text
Create a Slack bot.
https://github.com/BlakeWilliams/Elixir-Slack
(Easy, so no topic.)
Slide 24
Slide 24 text
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
Slide 25
Slide 25 text
Text editor?
VSCode with mjmcloug.vscode-elixir
works.
Slide 26
Slide 26 text
Format & lint.
InnerCotton https://github.com/ne-sachirou/inner_cotton is a set
of standard development tools.
mix cotton.init
mix cotton.lint --fix
Slide 27
Slide 27 text
Docker image (You need Docker :-)
Fix major ver.s both Erlang & Elixir.
docker run -it --rm nesachirou/elixir:1.9_erl22
Slide 28
Slide 28 text
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
Slide 29
Slide 29 text
https://speakerdeck.com/ne_sachirou/elixirwan-quan-nili-jie-sita
Slide 30
Slide 30 text
Advanced resources
Slide 31
Slide 31 text
Erlang in Anger
https://ymotongpoo.github.io/erlang-in-anger/text-ja.pdf
You want to read this… before production.
Slide 32
Slide 32 text
https://speakerdeck.com/ne_sachirou/sutetohurudeda-gui-mo-
akusesufalsearusoft-realtimenagemusabawoeasynitukuru
Slide 33
Slide 33 text
https://speakerdeck.com/ne_sachirou/elixir-on-containers
Slide 34
Slide 34 text
https://speakerdeck.com/ne_sachirou/phoenix-at-scale
Slide 35
Slide 35 text
https://speakerdeck.com/ne_sachirou/ddd-data-driven-development