DSL not working

[DohanKim]

problem: using DSL like README gives a compilation error (v 3.6.0)

reason: wrong macro definition

the codes in the WalEx.Event is defining macro like below.

defmodule MacroModule do
  defmacro __using__(_) do
    quote do
      defmacro define_hello(do: block) do
        quote do
          def hello() do
            unquote(block).("hello world")
          end
        end
      end
    end
  end
end

defmodule Test do
  use MacroModule

  define_hello(do: fn x -> IO.puts(x) end)
end

Test.hello()

this code gives an error.

     error: undefined function define_hello/1 (there is no such import)

       define_hello(do: fn x -> IO.puts(x) end)
        ^

You intended something like the one below per README.

defmodule MacroModule do
  defmacro __using__(_) do
    quote do
      import MacroModule
    end
  end

  defmacro define_hello(do: block) do
    quote do
      def hello() do
        unquote(block).("hello world")
      end
    end
  end
end

defmodule Test do
  use MacroModule

  define_hello(do: fn x -> IO.puts(x) end)
end

Test.hello()

• p.s: Using macro like this is not encouraged https://stackoverflow.com/questions/53065864/define-another-macro-inside-using

• it would be better to add test cases for the DSL usage.

• thank you for the effort to improve the library. I am gratefully using your library.

[cpursley]

Super, thank you @DohanKim !

What do you think of putting the Dsl logic into it's own module (dsl.ex or something like that)? This is something I've wanted to do for a while and keep event.ex just for the event struct & casting stuff.

[cpursley]

@DohanKim heads up that I just merged some additional changes to master which may break your PR. I think the main thing will be getting the events pid for tests will now work like this:

events_pid = find_worker_pid(destinations_supervisor_pid, DestinationsEventModules)

I moved Event under destinations and renamed the nodule to EventModules.

[DohanKim]

I agree with putting DSL logic into a separate module. let me try to implement it.

[DohanKim]

https://github.com/cpursley/walex/pull/36/commits/4a9a19a7318f650a4a0d66da562cc0c0b53de7be

• made separated dsl file
• to use DSL, need to explicitly declare import WalEx.Event.Dsl such as

  use WalEx.Event, name: :test_app
  import WalEx.Event.Dsl

I think it's more clear to users than importing the Dsl macro implicitly in WalEx.Event.

• moved event-related files into the event folder
• fixed failing test you mentioned

[DohanKim]

it seems that you are not using the word and concept of "DSL" anymore in the README file, so making the macro imported implicitly look more natural. changed the PR accordingly