Line numbers for functions

I just tried Cthulhu for exploring how the sum implementation works, and I must say it's pretty great, thank you :-)

One thing I noticed is that it seems hard to connect the current function to the source where it's defined, as there's no line numbers or file names. Would it be easy to put those in? (Related idea - provide an option to list the source of the current function, or otherwise open it in an editor like @edit? Though this might be straying from the use case you had in mind with Cthulhu?)