Create dynamic function with Elixir Macro

create_dynamic_func.ex

defmodule MyMacro do
  defmacro create_some_function_by_number(name, num, do: block) do
    params =
      for n <- 1..num do
        {"id#{n}", Macro.var(:"id#{n}", nil)}
      end

    # We can't call Macro.escape because it is for escaping values.
    # In this case, we have a mixture of values "id#{n}" and
    # expressions "Macro.var(...)", so we build the map AST by hand.
    pattern = {:%{}, [], params}

    conn =
      Macro.var(:conn, nil)

    quote do
      def unquote(:"#{name}")(unquote(conn), unquote(pattern)) do
        unquote(block)
      end
    end
  end
end

defmodule MyAppWeb.PageController do
  use MyAppWeb, :controller
  import MyMacro

  create_some_function_by_number :index, 1 do
    render(conn, "index.html")
  end
end