  Type systems provide software developers immediate feedback about a subset of
correctness properties of their programs. IDE integrations often take advantage
of type systems to present errors, suggest completions and even improve
navigation. On the other hand, understanding the time and energy consumption of
the execution of a program requires manual testing.
  In this paper, we identify existing work on using type systems for energy
awareness, and define the requirements for a practical approach, which the
existing approaches do not address fully.
  Furthermore, we also discuss how existing type systems can help generalize
refactors for energy-efficiency.
