Consider implementing line_profile.

Hi, thanks for your very useful library.

I'd love support for [line_profiler](https://github.com/rkern/line_profiler). I lack skills to implement this myself so I'm sorry but I can't offer a pull request. Would you be interested in such enhancement?

Start by reviewing the existing profiling decorators and the line_profiler API. Determine the intended integration points and behavior for line_profiler support; done means the library can use line_profiler through its existing profiling interface and the behavior is covered by tests.

Written by the indexing model from the issue text.