   defined in a code example is going to linger throughout the whole test suite
   run.
   """
-
-  defexception CompileError, error: nil, expression: nil do
-    def message(__MODULE__[error: error, expression: expr]) do
-      "#{inspect elem(error, 0)}: #{error.message} while parsing expression `#{expr}`"
-    end
-  end
 
   defrecord Test, fun_arity: nil, line: nil, expr: nil, expected: nil
 

    location = [line: line, file: Path.relative_to(file, System.cwd!)]
    stack    = Macro.escape [{ module, :__MODULE__, 0, location }]

    expr_ast     = string_to_ast(line, file, test.expr)
    expected_ast = string_to_ast(line, file, expected)

    quoted =
    quote do

    quoted
  end

  defp string_to_ast(module, line, file, expr) do
    location = [line: line, file: Path.relative_to(file, System.cwd!)]
    stack    = Macro.escape [{ module, :__MODULE__, 0, location }]
    try do
      Code.string_to_ast!(expr, line: line, file: file)
    rescue e ->
      quote do
        raise ExUnit.ExpectationError,
            [ prelude: "Expected doctest's expression",
              expected: unquote(expr),
              actual: "successfully",
              reason: "compile",
              instead: unquote(Macro.escape e) ],
            unquote(stack)
      end
    end
  end

