52 lines
1.3 KiB
Elixir
52 lines
1.3 KiB
Elixir
defmodule Protocols do
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use Koans
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@intro "Want to follow the rules? Adhere to the protocol!"
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defprotocol(School, do: def(enroll(person)))
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defimpl School, for: Any do
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def enroll(_) do
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"Pupil enrolled at school"
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end
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end
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defmodule Student do
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@derive School
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defstruct name: ""
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end
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defmodule(Musician, do: defstruct(name: "", instrument: ""))
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defmodule(Dancer, do: defstruct(name: "", dance_style: ""))
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defmodule(Baker, do: defstruct(name: ""))
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defimpl School, for: Musician do
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def enroll(musician) do
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"#{musician.name} signed up for #{musician.instrument}"
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end
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end
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defimpl School, for: Dancer do
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def enroll(dancer), do: "#{dancer.name} enrolled for #{dancer.dance_style}"
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end
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koan "Sharing an interface is the secret at school" do
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musician = %Musician{name: "Andre", instrument: "violin"}
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dancer = %Dancer{name: "Darcy", dance_style: "ballet"}
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assert School.enroll(musician) == ___
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assert School.enroll(dancer) == ___
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end
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koan "Sometimes we all use the same" do
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student = %Student{name: "Emily"}
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assert School.enroll(student) == ___
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end
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koan "If you don't comply you can't get in" do
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assert_raise ___, fn ->
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School.enroll(%Baker{name: "Delia"})
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end
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end
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end
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