defmodule TypeClass.Property do
  @moduledoc "A *very* simple prop checker"

  # (...)

  @doc "Run all properties for the type class"
  def run!(datatype, class, prop_name, times \\ 100) do
    property_module  = Module.concat(class, Property)

    # Irrelevant parts in this scenario are commented out.

    # custom_generator = Module.concat([class, "Proto", datatype]).__custom_generator__()

    data_generator =
    # if custom_generator do
    #   custom_generator
    # else
        Module.concat(TypeClass.Property.Generator, datatype).generate(nil)
    # end

    fn ->
      unless apply(property_module, prop_name, [data_generator]) do
        raise TypeClass.Property.FailedCheckError.new(datatype, class, prop_name)
      end
    end
    |> Stream.repeatedly()
    |> Enum.take(times)
  end

  # (...)

end