Sweet Elixir - Short

Around 60% of telecom passes through Erlang. Facebook uses it and RabbitMQ is built on it. It’s fast, concurrent, distributed, but its Prolog-inspired syntax leaves much to be desired. Ruby is beautiful and powerful, but struggles at scale and treats concurrency as a second class citizen. Elixir - a young, functional, meta programming language - aims to resolve this mighty conflict by providing a rosy syntax inspired by Ruby that compiles to Erlang VM compatible bytecode.
Together we’ll take a guided tour of Elixir basics and functional programming concepts like pattern matching, pipelines and tail-call recursion. From there we’ll explore the distributed and concurrent nature of Elixir, the fault tolerant features of OTP, and ways you can leverage Elixir in your existing architectures today.

Whether you roll with a Mac, Windows or Linux everyone will leave an Elixir programmer.

Transcript

1. Ryan Cromwell Sweet Elixir!
2. Pipeline What’s Elixir? |> Types, Functions, Modules |> Pattern Matching |> Maps, Structs, & Protocols |> Pipelines |> Processes |> OTP, Phoenix
3. Sweet Elixir! What’s Elixir?
4. Functional
5. Erlang VM
6. Concurrent
7. Distributed
8. Sweet Elixir! Setup
9. Mac #Mac! $> brew update! $> brew install erlang! $> brew install elixir! ! #Linux! <Your package manager here>! ! #Windows! PS> cinst elixir
10. SWEET ELIXIR! SECTION TITLE
11. $> iex ! iex(1)> IO.puts “hello world!”
12. $> elixir hello_world.exs hello world
13. elixirc hello_world.ex ! $> ls Elixir.HelloWorld.beam
14. $> mix deps.get $> mix compile $> mix phoenix.start
15. hex.pm
16. Sweet Elixir! Types
17. is_number 1 ! ! ! ! ! ! ! ! ! ! ! ! ! #=> true! ! is_integer 1! ! ! ! ! ! ! ! ! ! ! ! ! #=> true! ! is_number 2.1! ! ! ! ! ! ! ! ! ! ! ! #=> true! ! is_float 2.1! ! ! ! ! ! ! ! ! ! ! ! ! #=> true! ! is_integer 2.1! ! ! ! ! ! ! ! ! ! ! ! #=> false
18. 1 == 1.0!! ! ! ! ! ! ! ! ! ! ! ! ! ! #=> true! ! 1 === 1.0! ! ! ! ! ! ! ! ! ! ! ! ! ! #=> false
19. is_boolean true! ! ! ! ! ! ! ! ! ! ! #=> true! ! true or false! ! ! ! ! ! ! ! ! ! ! ! #=> true! ! true || false! ! ! ! ! ! ! ! ! ! ! ! #=> true
20. is_atom :selfConf!! ! ! ! ! ! ! ! ! #=> true! ! is_atom true! ! ! ! ! ! ! ! ! ! ! ! ! #=> true
21. is_list [1,2,3]! ! ! ! ! ! ! ! ! ! ! #=> true! ! length [1,2,3]! ! ! ! ! ! ! ! ! ! ! ! #=> 3! ! [1,2] ++ [3,4]! ! ! ! ! ! ! ! ! ! ! ! #=> [1,2,3,4]! ! iex> h Enum! ! iex> h Stream
22. is_tuple {1, “b”, :c}! ! ! ! ! ! ! ! #=> true! ! elem! {1, “b”, :c}, 1!! ! ! ! ! ! ! #=> “b”! ! t = {1, “b”, :c}! set_elem t, 2, :d!! ! ! ! ! ! ! ! ! #=> {1, “b”, :d}! ! Integer.parse “1.0a3”!! ! ! ! ! ! ! #=> {1, “.0a3”}
23. is_list ‘hello’! ! ! ! ! ! ! ! ! ! ! #=> true! ! is_list “hello”! ! ! ! ! ! ! ! ! ! ! #=> true! ! is_binary “hello”!! ! ! ! ! ! ! ! ! #=> true
24. “hello” <> “ world”! ! ! ! ! ! ! ! ! ! #=> “hello world”! ! who = “ryan”! “hello #{who}”! ! ! ! ! ! ! ! ! ! ! ! ! #=> “hello ryan”
25. SWEET ELIXIR! Anonymous Functions
26. add = fn (x, y) -> x + y end! ! add.(2,2)! ! ! ! ! ! ! ! ! ! ! #=> 4
27. do_calc = fn(x,y, calc) -> calc.(x,y) end! ! do_calc.(2,3, add)! ! ! ! ! ! ! ! ! #=> 5! ! do_calc.(2,4, &(&1 * &2))! ! ! ! ! #=> 8
28. SWEET ELIXIR! Modules
29. defmodule Weather do! ! def celsius_to_fahrenheit(celsius) do! ! ! (celsius * 1.8) + 32! ! end! ! ! def boiling, do: 100! ! def freezing, do: 0! end! ! Weather.celsius_to_fahrenheit(20) ! ! #=> 68.0
30. import alias defmodule USWeather do! ! import Weather, only: [freezing: 0,! ! ! ! celsius_to_fahrenheit: 1]! ! ! alias :math, as Math! ! ! def cold_in_michigan do! ! ! celsius_to_fahrenheit(freezing - 10)! ! end! end
31. SWEET ELIXIR! Pattern Matching
32. [head | tail] = [1,2,3,4,5]! ! head! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! #=> 1! ! tail! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! #=> [2,3,4,5]
33. {a,b,c}! = {1,”b”,:c}! ! a!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! #=> 1! ! b!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! #=> “b”! ! c!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! #=> :c
34. {a,b,:other}!= {1,”b”,:c}
35. {a,b,:other}!= {1,”b”,:c}! ! ** (MatchError) no match of right hand side value: {1, "b", :c}
36. Control Flow calculate = fn expression ->! case expression do! {:+, num1, num2} -> num1 + num2! {:-, num1, num2} -> num1 - num2! {:*, num1, 0} -> 0! {:*, num1, num2} -> num1 * num2! end! end
37. defmodule Countdown do! def run(from, to) when from >= to do! run(from, to, from)! end! ! def run(_from, to, current) when to == current do! IO.puts to! IO.puts "Done!"! end! ! def run(from, to, current) do! IO.puts current! run(from, to, current - 1)! end! end Function
38. defmodule PersonPrefixer do! def prefix(p = %{ gender: :male }), do: "Mr."! def prefix(p = %{ gender: :female }), do: "Mrs."! def prefix(p), do: ""! end! ! PersonPrefixer.prefix %{first: “Sandy”, gender: :female} #=> “Mrs”
39. SWEET ELIXIR! Maps Structs Protocols
40. Maps speaker = %{! first: “Ryan”,! last: “Cromwell”,! twitter: “@cromwellryan”,! “home town” => “Dayton, OH”! }! ! speaker[:twitter] #=> “@cromwellryan”! ! speaker[“Home Town”] #=> “Dayton, OH”
41. Structs defmodule Kid do! ! defstruct name: "ryan", age: 7! end
42. Protocols defprotocol Good do! @doc "Returns true if data is considered good"! def good?(data)! end
43. Ad-hoc Polymorphism defimpl Good, for: Kid do! ! def good?(%Kid{name: "Ryan"}), do: true! ! def good?(_), do: false! end! ! Good.good? %Kid{name: "Ryan"}! ! ! ! ! ! ! ! #> true! Good.good? %Kid{name: "Ben"}!! ! ! ! ! ! ! ! #> false
44. SWEET ELIXIR! Pipelines
45. Enum.map [1,2,3,4], fn (x) -> x * 2 !! ! ! ! ! #=> [2,4,6,8]! ! [1,2,3,4] |> Enum.map(fn (x) -> x *2)! ! ! ! ! #=> [2,4,6,8]
46. lines = String.split file_content, "\n"! lines = Stream.filter lines, &(String.length(&1) > 0)! lengths = Stream.map lines, &(String.split &1)! triangles = Stream.map lengths, &(list_to_tuple &1)! classifications = Stream.map triangles, &( %{sides: &1, classification: Classifier.classify &1} )! ! messages = Stream.map classifications, &( "Triangle #{inspect &1[:sides]} is #{&1[:classification]}" )! result = Enum.join(messages, "\n")! ! IO.puts result before
47. file_content! |> String.split("\n")! |> Stream.filter( &(String.length(&1) > 0) )! |> Stream.map( &(String.split &1) )! |> Stream.map( &(list_to_tuple &1) )! |> Stream.map( &(%{sides: &1, class: Classifier.classify &1}) )! |> Stream.map( &("Triangle #{inspect &1[:sides]} is #{&1[:class]}") )! |> Enum.join("\n")! |> IO.puts! after
48. SWEET ELIXIR! Processes
49. Process Process Process
50. pid = spawn fn ->! receive do! {sender, :ping} ->! IO.puts "Got ping"! send sender, :pong! end! end
51. Live Coding
52. SWEET ELIXIR! OTP
53. ‣ Supervisor ‣ GenServer ‣ GenFSM ‣ GenEvent ‣ Application
55. SWEET ELIXIR! phoenix
56. github.com/phoenixframework/phoenix
57. $> mix phoenix.new your_app /path/to/scaffold/your_app! ! $> mix do deps.get, compile! ! $> mix phoenix.start
58. Inspired by Rails defmodule ChatDemoEx.Router do! use Phoenix.Router! use Phoenix.Router.Socket, mount: "/ws"! ! plug Plug.Static, at: "/static", from: :chat_demo_ex! get "/", ChatDemoEx.Controllers.Pages, :index, as: :page! ! channel "rooms", Chat.Channels.Rooms! end
59. defmodule Chat.Channels.Rooms do! use Phoenix.Channel! ! def event(socket, "new:message", message) do! broadcast socket, "new:message", message! ! socket! end! end Elixir
60. Javascript chan.send("new:message", {! ! username: “cromwellryan”, ! ! body: “hello internets!”! });! !
61. SWEET ELIXIR! LEARN YOU SOME ELIXIR
62. Resources ‣ elixir-lang.org ‣ elixirsips.com ‣ elixirconf.com (July 25-26) ! ‣ PragProg: Programming Elixir ! ‣ github.com/cromwellryan/sweetelixir ‣ http://bit.ly/sweetelixir-short
63. THANKS! @cromwellryan ryan@heysparkbox.com