Elixir - introduction

Transcript

1. Elixir - Introduction
2. Karol Galanciak • Full-stack developer at • Twitter: @Azdaroth • blog: karolgalanciak.com, blog.ragnarson.com
3. Programming should be about transforming data
4. Programming should be about transforming data OOP:
5. Programming should be about transforming data OOP: • classes
6. Programming should be about transforming data OOP: • classes • objects
7. Programming should be about transforming data OOP: • classes • objects • state
8. Programming should be about transforming data OOP: • classes • objects • state • modelling real world with hierarchies
9. Programming should be about transforming data Elixir:
10. Programming should be about transforming data Elixir: getting things done
11. Why Elixir?
12. Why Elixir? • Functional
13. Why Elixir? • Functional: • immutability
14. Why Elixir? • Functional: • immutability • pattern matching
15. Why Elixir? • Functional: • pattern matching • immutability • side-effects free
16. Why Elixir? • Functional • Erlang VM
17. Why Elixir? • Functional • Erlang VM • Concurrency
18. Why Elixir? • Functional • Erlang VM • Concurrency • Syntax
19. Why Elixir? • Functional • Erlang VM • Concurrency • Syntax • Erlang compatible
20. Match operator • a = 1
21. Match operator • a = 1=> 1
22. Match operator • a = 1 => 1 • 1 = a
23. Match operator • a = 1 => 1 • 1 = a => 1
24. Match operator • a = 1 => 1 • 1 = a => 1 • 2 = a
25. Match operator • a = 1 => 1 • 1 = a => 1 • 2 = a => (MatchError) no match of right hand side value: 1
26. Match operator • a = 1 => 1 • 1 = a => 1 • 2 = a => (MatchError) no match of right hand side value: 1 • list = [1, 2, 3]
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
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
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
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
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” }
32. Types
33. Types • Value Types:
34. Types • Value Types: • Integers
35. Types • Value Types: • Integers • Floats
36. Types • Value Types: • Integers • Floats • Atoms (:like_ruby_symbol)
37. Types • Value Types: • Integers • Floats • Atoms (:like_ruby_symbol) • Ranges (1..100)
38. Types • Value Types: • Integers • Floats • Atoms (:like_ruby_symbol) • Ranges (1..100) • Regular expressions (%r{regexp})
39. Tpes • System types:
40. Types • System types: • PIDs
41. Types • System types: • PIDs • Ports
42. Types • System types: • PIDs • Ports • References
43. Types • Collection types:
44. Types • Collection types: • Tuples
45. Types • Collection types: • Tuples • => {:ok, ”content”}
46. Types • Collection types: • Tuples • => {:ok, ”content”} • => {:error, ”error message”}
47. Types • Collection types: • Tuples • => {:ok, ”content”} • => {:error, ”error message”} • Lists
48. Types • Collection types: • Tuples • => {:ok, ”content”} • => {:error, ”error message”} • Lists • => [1, 2, 3]
49. Types • Collection types: • Tuples • => {:ok, ”content”} • => {:error, ”error message”} • Lists • => [1, 2, 3] • => [1, 2, 3] ++ [4]
50. Types • Collection types: • Tuples • => {:ok, ”content”} • => {:error, ”error message”} • Lists • => [1, 2, 3] • => [1, 2, 3] ++ [4] • => [1, 2, 3] -- [1]
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]
52. Types • Collection types: • Keyword Lists
53. Types • Collection types: • Keyword Lists • => [name: ”Elixir”, status: ”awesome”]
54. Types • Collection types: • Keyword Lists • => [name: ”Elixir”, status: ”awesome”] • => [name: ”Elixir”, status: ”awesome”][:name]
55. Types • Collection types: • Keyword Lists • => [name: ”Elixir”, status: ”awesome”] • => [name: ”Elixir”, status: ”awesome”][:name] • Maps
56. Types • Collection types: • Keyword Lists • => [name: ”Elixir”, status: ”awesome”] • => [name: ”Elixir”, status: ”awesome”][:name] • Maps • %{”ruby” => ”oop”, :elixir => ”functional”}
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]
58. Functions
59. Functions • add_one = fn n -> n + 1 end
60. Functions • add_one = fn n -> n + 1 end • add_one.(1) => 2
61. Functions • add_one = fn n -> n + 1 end • add_one.(1) => 2 • square = &(&1 * &1)
62. Functions • add_one = fn n -> n + 1 end • add_one.(1) => 2 • square = &(&1 * &1) • => square.(3) => 9
63. Functions • add_one = fn n -> n + 1 end • add_one.(1) => 2 • square = &(&1 * &1) • => square.(3) => 9 • len = &Enum.count/1
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
65. Organizing code
66. Organizing code defmodule SomeName do end
67. Organizing code defmodule SomeName do def hello_world do IO.puts ”hello world” end end
68. Organizing code defmodule SomeName do def hello_world do IO.puts ”hello world” end end SomeName.hello_world => ”hello world”
69. Functions and Pattern Matching
70. Functions and Pattern Matching defmodule MySum do end
71. Functions and Pattern Matching defmodule MySum do def sum(array), do: _sum(0, array) end
72. Functions and Pattern Matching defmodule MySum do def sum(array), do: _sum(0, array) defp _sum(total, []), do: total end
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
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
75. Guard Clauses
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
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!
78. Pipe operator - |> ps awux | grep spring | awk '{print $2}' | xargs kill
79. Pipe operator - |> [1, 2, 3] |> Enum.map(&(&1 * &1)) |> Enum.map(&to_string/1) |> Enum.map(&(&1 <> "0")) |> Enum.join(" - ") => "10 - 40 - 90"
80. List comprehensions
81. List comprehensions for x <- [1, 2, 3], y <- [10, 20, 30], x * y > 20, do: x + y => [31, 22, 32, 13, 23, 33]
82. Cond, if, case
83. Cond, if, case if 1 == 1 do ”I’m truthy” else ”I’m falsey” end
84. Cond, if, case if 1 == 1 do ”I’m truthy” else ”I’m falsey” end unless 1 == 1, do: ”error”, else: ”ok”
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
86. Cond, if, case case File.open(”some_file.exs”) do { :ok, file } => IO.puts ”success” { :error, reason } => IO.puts ”error: #{reason}” end
87. Structs
88. Structs defmodule User do defstruct fullname: "", email: "" end
89. Structs defmodule User do defstruct fullname: "", email: "" end user = %User{fullname: ”name”}
90. Structs defmodule User do defstruct fullname: "", email: "" end user = %User{fullname: ”name”} user.fullname = > ”name”
91. Structs defmodule User do defstruct fullname: "", email: "" def has_email?(user) do String.length(user.email) > 0 end end
92. Macros
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
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
95. Concurrency
96. Concurrency defmodule Spawnee do def hi do receive do { sender, message } -> send sender, { :ok, "Hi #{message}!"} end end end
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" }
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
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
100. Encapsulating state by processes
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
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
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
104. Elixir FTW!