Intro to OTP in Elixir

September 8th, 2016 @ Full Stack Talks

https://youtu.be/CJT8wPnmjTM

Transcript

2. OTP • Erlang • Tools • Libraries • Design Principles • Other Stuff
3. Processes
4. iex(1)>
5. iex(1)> spawn(fn -> IO.puts “Hello Full Stack” end)
6. iex(1)> spawn(fn -> IO.puts “Hello Full Stack” end) Hello Full Stack #PID<0.64.0> iex(2)>
7. iex(2)> pid = spawn(fn -> IO.puts “Hello Full Stack” end) Hello Full Stack #PID<0.65.0> iex(3)> Process.alive?(pid) false iex(4)>
8. Error Handling
9. Supervisors
11. “The Zen of Erlang”
15. Messages
16. FantasyTeam
17. State
18. defmodule FantasyTeam.Basic do def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end end
19. defmodule FantasyTeam.Basic do def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do ...
20. defmodule FantasyTeam.Basic do def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do ...
21. defmodule FantasyTeam.Basic do def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do ...
22. defmodule FantasyTeam.Basic do def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do ...
23. defmodule FantasyTeam.Basic do def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do ...
24. def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, state) loop(new_state)
25. def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, state) loop(new_state)
26. def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, state) loop(new_state)
27. def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, state) loop(new_state)
28. def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, state) loop(new_state)
29. def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, state) loop(state)
30. def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, state) loop(state)
31. def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, state) loop(state)
32. iex(1)>
33. iex(1)> pid = FantasyTeam.Basic.start_link #PID<0.65.0> iex(2)>
34. iex(1)> pid = FantasyTeam.Basic.start_link #PID<0.65.0> iex(2)> send(pid, {:add, “Russell Wilson”}) {:add, “Russell Wilson”} iex(3)>
35. iex(1)> pid = FantasyTeam.Basic.start_link #PID<0.65.0> iex(2)> send(pid, {:add, “Russell Wilson”}) {:add, “Russell Wilson”} iex(3)> send(pid, {:add, “Doug Baldwin”}) {:add, “Doug Baldwin”} iex(4)>
36. iex(1)> pid = FantasyTeam.Basic.start_link #PID<0.65.0> iex(2)> send(pid, {:add, “Russell Wilson”}) {:add, “Russell Wilson”} iex(3)> send(pid, {:add, “Doug Baldwin”}) {:add, “Doug Baldwin”} iex(4)> send(pid, {:remove, “Doug Baldwin”}) {:remove, “Doug Baldwin”} iex(5)>
37. iex(1)> pid = FantasyTeam.Basic.start_link #PID<0.65.0> iex(2)> send(pid, {:add, “Russell Wilson”}) {:add, “Russell Wilson”} iex(3)> send(pid, {:add, “Doug Baldwin”}) {:add, “Doug Baldwin”} iex(4)> send(pid, {:remove, “Doug Baldwin”}) {:remove, “Doug Baldwin”} iex(5)> send(pid, {:team, self}) {:team, #PID<0.123.0>} iex(6)>
38. iex(1)> pid = FantasyTeam.Basic.start_link #PID<0.65.0> iex(2)> send(pid, {:add, “Russell Wilson”}) {:add, “Russell Wilson”} iex(3)> send(pid, {:add, “Doug Baldwin”}) {:add, “Doug Baldwin”} iex(4)> send(pid, {:remove, “Doug Baldwin”}) {:remove, “Doug Baldwin”} iex(5)> send(pid, {:team, self}) {:team, #PID<0.123.0>} iex(6)> flush {:ok, %{“Russell Wilson” => %{position: “QB”, team: “SEA”}}
39. defmodule FantasyTeam.Basic do def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end end
40. GenServer
41. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) end def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks def init(:ok) do {:ok, %{}} end def handle_cast({:add, name}, state) do player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) {:noreply, new_state} end def handle_cast({:remove, name}, state) do new_state = Map.delete(state, name) {:noreply, new_state} end def handle_call(:team, _from, state) do {:reply, state, state} end end defmodule FantasyTeam.Basic do def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end end
42. defmodule FantasyTeam.MyGenServer do use GenServer defmodule FantasyTeam.Basic do def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end end
43. def start_link do GenServer.start_link(__MODULE__, :ok, []) end # Callbacks def init(:ok) do {:ok, %{}} end def handle_cast({:add, name}, state) do player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) {:noreply, new_state} end def handle_cast({:remove, name}, state) do new_state = Map.delete(state, name) {:noreply, new_state} end def handle_call(:team, _from, state) do {:reply, state, state} end def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end
44. def start_link do GenServer.start_link(__MODULE__, :ok, []) end # Callbacks def init(:ok) do {:ok, %{}} end def handle_cast({:add, name}, state) do player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) {:noreply, new_state} end def handle_cast({:remove, name}, state) do new_state = Map.delete(state, name) {:noreply, new_state} end def handle_call(:team, _from, state) do {:reply, state, state} end def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end
45. def start_link do GenServer.start_link(__MODULE__, :ok, []) end # Callbacks def init(:ok) do {:ok, %{}} end def handle_cast({:add, name}, state) do player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) {:noreply, new_state} end def handle_cast({:remove, name}, state) do new_state = Map.delete(state, name) {:noreply, new_state} end def handle_call(:team, _from, state) do {:reply, state, state} end def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end
46. def start_link do GenServer.start_link(__MODULE__, :ok, []) end # Callbacks def init(:ok) do {:ok, %{}} end def handle_cast({:add, name}, state) do player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) {:noreply, new_state} end def handle_cast({:remove, name}, state) do new_state = Map.delete(state, name) {:noreply, new_state} end def handle_call(:team, _from, state) do {:reply, state, state} end def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end
47. def start_link do GenServer.start_link(__MODULE__, :ok, []) end # Callbacks def init(:ok) do {:ok, %{}} end def handle_cast({:add, name}, state) do player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) {:noreply, new_state} end def handle_cast({:remove, name}, state) do new_state = Map.delete(state, name) {:noreply, new_state} end def handle_call(:team, _from, state) do {:reply, state, state} end def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end
48. def start_link do GenServer.start_link(__MODULE__, :ok, []) end # Callbacks def init(:ok) do {:ok, %{}} end def handle_cast({:add, name}, state) do player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) {:noreply, new_state} end def handle_cast({:remove, name}, state) do new_state = Map.delete(state, name) {:noreply, new_state} end def handle_call(:team, _from, state) do {:reply, state, state} end def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end
49. def start_link do GenServer.start_link(__MODULE__, :ok, []) end # Callbacks def init(:ok) do {:ok, %{}} end def handle_cast({:add, name}, state) do player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) {:noreply, new_state} end def handle_cast({:remove, name}, state) do new_state = Map.delete(state, name) {:noreply, new_state} end def handle_call(:team, _from, state) do {:reply, state, state} end def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end
50. def start_link do GenServer.start_link(__MODULE__, :ok, []) end # Callbacks def init(:ok) do {:ok, %{}} end def handle_cast({:add, name}, state) do player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) {:noreply, new_state} end def handle_cast({:remove, name}, state) do new_state = Map.delete(state, name) {:noreply, new_state} end def handle_call(:team, _from, state) do {:reply, state, state} end def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end
51. def start_link do GenServer.start_link(__MODULE__, :ok, []) end # Callbacks def init(:ok) do {:ok, %{}} end def handle_cast({:add, name}, state) do player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) {:noreply, new_state} end def handle_cast({:remove, name}, state) do new_state = Map.delete(state, name) {:noreply, new_state} end def handle_call(:team, _from, state) do {:reply, state, state} end def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end
52. def start_link do GenServer.start_link(__MODULE__, :ok, []) end # Callbacks def init(:ok) do {:ok, %{}} end def handle_cast({:add, name}, state) do player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) {:noreply, new_state} end def handle_cast({:remove, name}, state) do new_state = Map.delete(state, name) {:noreply, new_state} end def handle_call(:team, _from, state) do {:reply, state, state} end def start_link do spawn_link(__MODULE__, :loop, [%{}]) end def loop(state) do receive do {:add, name} -> player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) loop(new_state) {:remove, name} -> new_state = Map.delete(state, name) loop(new_state) {:team, pid} -> send(pid, {:ok, state}) loop(state) end end
53. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
54. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
55. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
56. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
57. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
58. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
59. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
60. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
61. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
62. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
63. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
64. defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks def init(:ok) do {:ok, %{}} end def handle_cast({:add, name}, state) do player = FantasyTeam.Player.find(name) new_state = Map.put(state, name, player) {:noreply, new_state} end def handle_cast({:remove, name}, state) do new_state = Map.delete(state, name) {:noreply, new_state} end def handle_call(:team, _from, state) do {:reply, state, state} end end
65. defmodule FantasyTeam.SingleServer do use GenServer @name __MODULE__ # API def start_link do GenServer.start_link(__MODULE__, :ok, name: @name) end def add(name) do GenServer.cast(@name, {:add, name}) def def remove(name) do GenServer.cast(@name, {:remove, name}) end def team do GenServer.call(@name, :team) end # Callbacks ... defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
66. defmodule FantasyTeam.SingleServer do use GenServer @name __MODULE__ # API def start_link do GenServer.start_link(__MODULE__, :ok, name: @name) end def add(name) do GenServer.cast(@name, {:add, name}) def def remove(name) do GenServer.cast(@name, {:remove, name}) end def team do GenServer.call(@name, :team) end # Callbacks ... defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
67. defmodule FantasyTeam.SingleServer do use GenServer @name __MODULE__ # API def start_link do GenServer.start_link(__MODULE__, :ok, name: @name) end def add(name) do GenServer.cast(@name, {:add, name}) def def remove(name) do GenServer.cast(@name, {:remove, name}) end def team do GenServer.call(@name, :team) end # Callbacks ... defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
68. defmodule FantasyTeam.SingleServer do use GenServer @name __MODULE__ # API def start_link do GenServer.start_link(__MODULE__, :ok, name: @name) end def add(name) do GenServer.cast(@name, {:add, name}) def def remove(name) do GenServer.cast(@name, {:remove, name}) end def team do GenServer.call(@name, :team) end # Callbacks ... defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
69. defmodule FantasyTeam.SingleServer do use GenServer @name __MODULE__ # API def start_link do GenServer.start_link(__MODULE__, :ok, name: @name) end def add(name) do GenServer.cast(@name, {:add, name}) def def remove(name) do GenServer.cast(@name, {:remove, name}) end def team do GenServer.call(@name, :team) end # Callbacks ... defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
70. defmodule FantasyTeam.SingleServer do use GenServer @name __MODULE__ # API def start_link do GenServer.start_link(__MODULE__, :ok, name: @name) end def add(name) do GenServer.cast(@name, {:add, name}) def def remove(name) do GenServer.cast(@name, {:remove, name}) end def team do GenServer.call(@name, :team) end # Callbacks ... defmodule FantasyTeam.MyGenServer do use GenServer # API def start_link do GenServer.start_link(__MODULE__, :ok, []) end def add(pid, name) do GenServer.cast(pid, {:add, name}) def def remove(pid, name) do GenServer.cast(pid, {:remove, name}) end def team(pid) do GenServer.call(pid, :team) end # Callbacks ...
71. iex(1)>
72. iex(1)> FantasyTeam.SingleServer.start_link {:ok, #PID<0.65.0>} iex(2)>
73. iex(1)> FantasyTeam.SingleServer.start_link {:ok, #PID<0.65.0>} iex(2)> FantasyTeam.SingleServer.add(“Russell Wilson”) :ok iex(3)>
74. iex(1)> FantasyTeam.SingleServer.start_link {:ok, #PID<0.65.0>} iex(2)> FantasyTeam.SingleServer.add(“Russell Wilson”) :ok iex(3)> FantasyTeam.SingleServer.add(“Doug Baldwin”) :ok iex(4)>
75. iex(1)> FantasyTeam.SingleServer.start_link {:ok, #PID<0.65.0>} iex(2)> FantasyTeam.SingleServer.add(“Russell Wilson”) :ok iex(3)> FantasyTeam.SingleServer.add(“Doug Baldwin”) :ok iex(4)> FantasyTeam.SingleServer.remove(“Doug Baldwin”) :ok iex(5)>
76. iex(1)> FantasyTeam.SingleServer.start_link {:ok, #PID<0.65.0>} iex(2)> FantasyTeam.SingleServer.add(“Russell Wilson”) :ok iex(3)> FantasyTeam.SingleServer.add(“Doug Baldwin”) :ok iex(4)> FantasyTeam.SingleServer.remove(“Doug Baldwin”) :ok iex(5)> FantasyTeam.SingleServer.team %{“Russell Wilson” => %{position: “QB”, team: “SEA”}} iex(6)>
77. Recap
78. Agents & Tasks
79. defmodule FantasyTeam.MyAgent do def start_link do Agent.start_link(fn -> %{} end) end def add(pid, name) do player = FantasyTeam.Player.find(name) Agent.get_and_update(pid, fn(x) -> {player, Map.put(x, name, player)} end) :ok end def remove(pid, name) do Agent.update(pid, fn(x) -> Map.delete(x, name) end) end def team(pid) do Agent.get(pid, fn(x) -> x end) end end
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