 end
 
 defmodule BadArityError do
-  defexception [function: nil, args: nil]
+  defexception [:function, :args]
 
   def message(exception) do
     fun  = exception.function

end

defmodule CompileError do
  defexception [file: nil, line: nil, description: "compile error"]

  def message(%{file: file, line: line, description: description}) do
    Exception.format_file_line(file && Path.relative_to_cwd(file), line) <>

end

defmodule BadFunctionError do
  defexception [:term]

  def message(exception) do
    "expected a function, got: #{inspect(exception.term)}"
