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Demo of issue with defprotocol
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defprotocol Animal do | |
@fallback_to_any true | |
def warn(arg, arg2) | |
def greet(arg) | |
def speak(arg) | |
# Here I'm getting | |
# == Compilation error in file lib/animal.ex == | |
# ** (CompileError) lib/animal.ex:6: undefined function defdelegate/2 (there is no such import) | |
# Then go to line 48 | |
# | |
defdelegate kind(arg), to: Animal.Any | |
defdelegate describe(arg), to: Animal.Any | |
end | |
defimpl Animal, for: Any do | |
def greet(_), do: "" | |
def warn(_, _), do: "" | |
def speak(_), do: "" | |
def kind(animal) do | |
animal.__struct__ | |
|> Module.split() | |
|> List.last() | |
|> String.downcase() | |
end | |
def describe(animal) do | |
"Animal #{Animal.kind(animal)} named by #{animal.name}!" | |
end | |
end | |
defimpl Animal, for: Dog do | |
def warn(dog, arg) do | |
IO.puts("Warning, #{dog.name}! It is #{arg}!!!") | |
end | |
def greet(_) do | |
IO.puts("Greetings!") | |
end | |
def speak(_) do | |
IO.puts("Imma speaking!!!") | |
end | |
end | |
defmodule Dog do | |
# Here I'm not getting any errors | |
# Would be grateful for help, it's kinda tricky to grasp the | |
# concept when Elixir won't let me do that. | |
# Maybe something was changed in some major patch, not sure. | |
defdelegate(kind(arg), to: Animal.Any) | |
defdelegate(describe(arg), to: Animal.Any) | |
@enforce_keys [:name] | |
alias __MODULE__ | |
defstruct name: "" | |
def new(name), do: %Dog{name: name} | |
end |
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