title: Using a value of a map stored in a module attribute in function pattern matching
body: <p>Given that module attributes are resolved at compilation, I thought the following two line pairs would be equivalent but the second generates a <code>cannot invoke remote function</code> error.  What I'm trying to do is use a module attribute containing a map as an <code>enum</code>. Then I want to pattern match in the function against one of the <code>enum</code>'s values.</p>
  
  <pre><code>@my_guard "bar" 
  
  def foo(@my_guard), do: "bar"
  
  
  @my_map %{guard: "bar"}
  
  def foo(@my_map.guard), do: "bar"
  </code></pre>