Elixir - introduction

Transcript

1. Elixir - Introduction
   

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2. Karol Galanciak
   • Full-stack developer at
   • Twitter: @Azdaroth
   • blog: karolgalanciak.com, blog.ragnarson.com
   

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3. Programming should be
   about transforming data
   

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4. Programming should be
   about transforming data
   OOP:
   

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5. Programming should be
   about transforming data
   OOP:
   • classes
   

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6. Programming should be
   about transforming data
   OOP:
   • classes
   • objects
   

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7. Programming should be
   about transforming data
   OOP:
   • classes
   • objects
   • state
   

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8. Programming should be
   about transforming data
   OOP:
   • classes
   • objects
   • state
   • modelling real world with hierarchies
   

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9. Programming should be
   about transforming data
   Elixir:
   

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10. Programming should be
    about transforming data
    Elixir: getting things done
    

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11. Why Elixir?
    

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12. Why Elixir?
    • Functional
    

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13. Why Elixir?
    • Functional:
    • immutability
    

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14. Why Elixir?
    • Functional:
    • immutability
    • pattern matching
    

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15. Why Elixir?
    • Functional:
    • pattern matching
    • immutability
    • side-effects free
    

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16. Why Elixir?
    • Functional
    • Erlang VM
    

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17. Why Elixir?
    • Functional
    • Erlang VM
    • Concurrency
    

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18. Why Elixir?
    • Functional
    • Erlang VM
    • Concurrency
    • Syntax
    

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19. Why Elixir?
    • Functional
    • Erlang VM
    • Concurrency
    • Syntax
    • Erlang compatible
    

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20. Match operator
    • a = 1
    

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21. Match operator
    • a = 1=> 1
    

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22. Match operator
    • a = 1 => 1
    • 1 = a
    

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23. Match operator
    • a = 1 => 1
    • 1 = a => 1
    

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24. Match operator
    • a = 1 => 1
    • 1 = a => 1
    • 2 = a
    

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25. Match operator
    • a = 1 => 1
    • 1 = a => 1
    • 2 = a => (MatchError) no match of right hand side
    value: 1
    

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26. Match operator
    • a = 1 => 1
    • 1 = a => 1
    • 2 = a => (MatchError) no match of right hand side
    value: 1
    • list = [1, 2, 3]
    

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27. Match operator
    • a = 1 => 1
    • 1 = a => 1
    • 2 = a => (MatchError) no match of right hand side
    value: 1
    • list = [1, 2, 3]
    • [a, b, c] = list
    

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28. Match operator
    • a = 1 => 1
    • 1 = a => 1
    • 2 = a => (MatchError) no match of right hand side
    value: 1
    • list = [1, 2, 3]
    • [a, b, c] = list
    • [1, b, 3] = list
    

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29. Match operator
    • a = 1 => 1
    • 1 = a => 1
    • 2 = a => (MatchError) no match of right hand side value: 1
    • list = [1, 2, 3]
    • [a, b, c] = list
    • [1, b, 3] = list
    • [2, 2, 3] = list
    

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30. Match operator
    • a = 1 => 1
    • 1 = a => 1
    • 2 = a => (MatchError) no match of right hand side value: 1
    • list = [1, 2, 3]
    • [a, b, c] = list
    • [1, b, 3] = list
    • [2, 2, 3] = list
    • [d, _, _] = list
    

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31. Match operator
    • a = 1 => 1
    • 1 = a => 1
    • 2 = a => (MatchError) no match of right hand side value: 1
    • list = [1, 2, 3]
    • [a, b, c] = list
    • [1, b, 3] = list
    • [2, 2, 3] = list
    • [d, _, _] = list
    • { status, _ } = { :ok, ”content” }
    

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32. Types
    

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33. Types
    • Value Types:
    

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34. Types
    • Value Types:
    • Integers
    

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35. Types
    • Value Types:
    • Integers
    • Floats
    

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36. Types
    • Value Types:
    • Integers
    • Floats
    • Atoms (:like_ruby_symbol)
    

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37. Types
    • Value Types:
    • Integers
    • Floats
    • Atoms (:like_ruby_symbol)
    • Ranges (1..100)
    

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38. Types
    • Value Types:
    • Integers
    • Floats
    • Atoms (:like_ruby_symbol)
    • Ranges (1..100)
    • Regular expressions (%r{regexp})
    

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39. Tpes
    • System types:
    

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40. Types
    • System types:
    • PIDs
    

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41. Types
    • System types:
    • PIDs
    • Ports
    

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42. Types
    • System types:
    • PIDs
    • Ports
    • References
    

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43. Types
    • Collection types:
    

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44. Types
    • Collection types:
    • Tuples
    

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45. Types
    • Collection types:
    • Tuples
    • => {:ok, ”content”}
    

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46. Types
    • Collection types:
    • Tuples
    • => {:ok, ”content”}
    • => {:error, ”error message”}
    

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47. Types
    • Collection types:
    • Tuples
    • => {:ok, ”content”}
    • => {:error, ”error message”}
    • Lists
    

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48. Types
    • Collection types:
    • Tuples
    • => {:ok, ”content”}
    • => {:error, ”error message”}
    • Lists
    • => [1, 2, 3]
    

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49. Types
    • Collection types:
    • Tuples
    • => {:ok, ”content”}
    • => {:error, ”error message”}
    • Lists
    • => [1, 2, 3]
    • => [1, 2, 3] ++ [4]
    

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50. Types
    • Collection types:
    • Tuples
    • => {:ok, ”content”}
    • => {:error, ”error message”}
    • Lists
    • => [1, 2, 3]
    • => [1, 2, 3] ++ [4]
    • => [1, 2, 3] -- [1]
    

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51. Types
    • Collection types:
    • Tuples
    • => {:ok, ”content”}
    • => {:error, ”error message”}
    • Lists
    • => [1, 2, 3]
    • => [1, 2, 3] ++ [4]
    • => [1, 2, 3] -- [1]
    • => 1 in [1, 2, 3]
    

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52. Types
    • Collection types:
    • Keyword Lists
    

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53. Types
    • Collection types:
    • Keyword Lists
    • => [name: ”Elixir”, status: ”awesome”]
    

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54. Types
    • Collection types:
    • Keyword Lists
    • => [name: ”Elixir”, status: ”awesome”]
    • => [name: ”Elixir”, status: ”awesome”][:name]
    

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55. Types
    • Collection types:
    • Keyword Lists
    • => [name: ”Elixir”, status: ”awesome”]
    • => [name: ”Elixir”, status: ”awesome”][:name]
    • Maps
    

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56. Types
    • Collection types:
    • Keyword Lists
    • => [name: ”Elixir”, status: ”awesome”]
    • => [name: ”Elixir”, status: ”awesome”][:name]
    • Maps
    • %{”ruby” => ”oop”, :elixir => ”functional”}
    

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57. Types
    • Collection types:
    • Keyword Lists
    • => [name: ”Elixir”, status: ”awesome”]
    • => [name: ”Elixir”, status: ”awesome”][:name]
    • Maps
    • %{”ruby” => ”oop”, :elixir => ”functional”}
    • %{”ruby” => ”oop”, :elixir => ”functional”}[:elixir]
    

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58. Functions
    

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59. Functions
    • add_one = fn n -> n + 1 end
    

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60. Functions
    • add_one = fn n -> n + 1 end
    • add_one.(1) => 2
    

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61. Functions
    • add_one = fn n -> n + 1 end
    • add_one.(1) => 2
    • square = &(&1 * &1)
    

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62. Functions
    • add_one = fn n -> n + 1 end
    • add_one.(1) => 2
    • square = &(&1 * &1)
    • => square.(3) => 9
    

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63. Functions
    • add_one = fn n -> n + 1 end
    • add_one.(1) => 2
    • square = &(&1 * &1)
    • => square.(3) => 9
    • len = &Enum.count/1
    

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64. Functions
    • add_one = fn n -> n + 1 end
    • add_one.(1) => 2
    • square = &(&1 * &1)
    • => square.(3) => 9
    • len = &Enum.count/1
    • len.([1, 2, 3]) => 3
    

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65. Organizing code
    

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66. Organizing code
    defmodule SomeName do
    end
    

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67. Organizing code
    defmodule SomeName do
    def hello_world do
    IO.puts ”hello world”
    end
    end
    

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68. Organizing code
    defmodule SomeName do
    def hello_world do
    IO.puts ”hello world”
    end
    end
    SomeName.hello_world
    => ”hello world”
    

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69. Functions and Pattern
    Matching
    

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70. Functions and Pattern
    Matching
    defmodule MySum do
    end
    

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71. Functions and Pattern
    Matching
    defmodule MySum do
    def sum(array), do: _sum(0, array)
    end
    

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72. Functions and Pattern
    Matching
    defmodule MySum do
    def sum(array), do: _sum(0, array)
    defp _sum(total, []), do: total
    end
    

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73. Functions and Pattern
    Matching
    defmodule MySum do
    def sum(array), do: _sum(0, array)
    defp _sum(total, []), do: total
    defp _sum(total, [head | tail]), do: _sum(total +
    head, tail)
    end
    

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74. Functions and Pattern
    Matching
    defmodule MySum do
    def sum([head | tail]), do: _sum(head, tail)
    defp _sum(total, []), do: total
    defp _sum(total, [head | tail]), do: _sum(total +
    head, tail)
    end
    MySum.sum([1, 2, 3]) => 6
    

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75. Guard Clauses
    

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76. Guard Clauses
    defmodule NumberType do
    def print_type(num) when num < 0 do
    IO.puts "#{num} - I’m negative!"
    end
    def print_type(num) when num == 0 do
    IO.puts "I’m 0!"
    end
    def print_type(num) when num > 0 do
    IO.puts "#{num} - I’m positive!"
    end
    end
    

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77. Guard Clauses
    defmodule NumberType do
    def print_type(num) when num < 0 do
    IO.puts "#{num} - I’m negative!"
    end
    def print_type(num) when num == 0 do
    IO.puts "I’m 0!"
    end
    def print_type(num) when num > 0 do
    IO.puts "#{num} - I’m positive!"
    end
    end
    • NumberType.print_type(1) => 1 - I’m positive!
    • NumberType.print_type(0) => I’m 0!
    • NumberType.print_type(-1) => -1 - I’m negative!
    

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78. Pipe operator - |>
    ps awux | grep spring | awk '{print $2}' | xargs kill
    

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79. Pipe operator - |>
    [1, 2, 3]
    |> Enum.map(&(&1 * &1))
    |> Enum.map(&to_string/1)
    |> Enum.map(&(&1 <> "0"))
    |> Enum.join(" - ")
    => "10 - 40 - 90"
    

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80. List comprehensions
    

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81. List comprehensions
    for x <- [1, 2, 3], y <- [10, 20, 30], x * y > 20, do: x + y
    => [31, 22, 32, 13, 23, 33]
    

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82. Cond, if, case
    

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83. Cond, if, case
    if 1 == 1 do
    ”I’m truthy”
    else
    ”I’m falsey”
    end
    

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84. Cond, if, case
    if 1 == 1 do
    ”I’m truthy”
    else
    ”I’m falsey”
    end
    unless 1 == 1, do: ”error”, else: ”ok”
    

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85. Cond, if, case
    cond do
    rem(number, 3) == 0 and rem(number, 5) == 0 -> "FizzBuzz"
    rem(number, 3) == 0 -> "Fizz"
    rem(number, 5) == 0 -> "Buzz"
    true -> number
    end
    

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86. Cond, if, case
    case File.open(”some_file.exs”) do
    { :ok, file } => IO.puts ”success”
    { :error, reason } => IO.puts ”error: #{reason}”
    end
    

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87. Structs
    

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88. Structs
    defmodule User do
    defstruct fullname: "", email: ""
    end
    

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89. Structs
    defmodule User do
    defstruct fullname: "", email: ""
    end
    user = %User{fullname: ”name”}
    

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90. Structs
    defmodule User do
    defstruct fullname: "", email: ""
    end
    user = %User{fullname: ”name”}
    user.fullname = > ”name”
    

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91. Structs
    defmodule User do
    defstruct fullname: "", email: ""
    def has_email?(user) do
    String.length(user.email) > 0
    end
    end
    

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92. Macros
    

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93. Macros
    defmodule Test do
    require Plus
    Plus.add_n(3)
    Plus.add_n(4)
    end
    Test.add_3(4) => 7
    Test.add_4(5) => 9
    

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94. Macros
    defmodule Plus do
    defmacro add_n(number) do
    name = String.to_atom("add_#{number}")
    quote do
    def unquote(name)(other_number) do
    other_number + unquote(number)
    end
    end
    end
    end
    

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95. Concurrency
    

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96. Concurrency
    defmodule Spawnee do
    def hi do
    receive do
    { sender, message } -> send sender, { :ok, "Hi
    #{message}!"}
    end
    end
    end
    

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97. Concurrency
    defmodule Spawnee do
    def hi do
    receive do
    { sender, message } -> send sender, { :ok, "Hi
    #{message}!"}
    end
    end
    end
    pid = spawn(Spawnee, :hi, [])
    send pid, { self, "Elixir" }
    

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98. Concurrency
    defmodule Spawnee do
    def hi do
    receive do
    { sender, message } -> send sender, { :ok, "Hi #{message}!"}
    end
    end
    end
    pid = spawn(Spawnee, :hi, [])
    send pid, { self, "Elixir" }
    receive do
    { :ok, message } -> IO.puts message
    end
    

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99. Concurrency
    defmodule Spawnee do
    def hi do
    receive do
    { sender, message } -> send sender, { :ok, "Hi #{message}!"}
    end
    end
    end
    pid = spawn(Spawnee, :hi, [])
    send pid, { self, "Elixir" }
    receive do
    { :ok, message } -> IO.puts message
    end
    =>
    Hi Elixir!
    :ok
    

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100. Encapsulating state by
     processes
     

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101. Encapsulating state by
     processes
     defmodule Counter do
     def start do
     do_count(0)
     end
     defp do_count(current_number) do
     receive do
     { :increment, listener } ->
     send listener, current_number + 1
     do_count(current_number + 1)
     end
     end
     end
     

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102. Encapsulating state by
     processes
     defmodule Counter do
     def start do
     do_count(0)
     end
     defp do_count(current_number) do
     receive do
     { :increment, listener } ->
     send listener, current_number + 1
     do_count(current_number + 1)
     end
     end
     end
     counter_pid = spawn(Counter, :start, [])
     send(counter_pid, { :increment, self })
     receive do count -> count end
     => 1
     

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103. Encapsulating state by
     processes
     defmodule Counter do
     def start do
     do_count(0)
     end
     defp do_count(current_number) do
     receive do
     { :increment, listener } ->
     send listener, current_number + 1
     do_count(current_number + 1)
     end
     end
     end
     counter_pid = spawn(Counter, :start, [])
     send(counter_pid, { :increment, self })
     receive do count -> count end
     => 1
     send(counter_pid, { :increment, self })
     receive do count -> count end
     => 2
     

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104. Elixir FTW!
     

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