defprotocol bug?

[Maximiliano Guzenski]

Hi, 

I'm trying a simple to implement defprotocol/defimpl but I recevei always a error:

ps.: Activity is a Ector module, I using phoenix

defprotocol D4.Policy do

  def scoped(a, query, conn)

end

defimpl D4.Policy, for: D4.Activity do

  def scoped(a, query, conn) do

    IO.puts "hi"

  end

end

D4.Policy.scoped(D4.Activity, 1, 2)

error -->

** (Protocol.UndefinedError) protocol D4.Policy not implemented for D4.Activity

    (d4) web/lib/policy.ex:1: D4.Policy.impl_for!/1

    (d4) web/lib/policy.ex:3: D4.Policy.scoped/3

[Ben Wilson]

As shown in the documentation on defprotocol, you need to define a struct in the D4.Activity module, and then pass a %D4.Activity{} struct to the protocol function. As it is you're just passing in a module name which is an Atom, and there is no protocol implementation for atoms.

[Maximiliano Guzenski]

Yes, my mistake... struct(D4.Activity) resolved it... thanks !