i have a compiler Im writing in elixir. I need to trace execution of  logic to pinpoint bugs. 
I have many tests I want to debug individually but I can run only the full test suite. 
I want to create a couple of macros/functions that'd enable me to debug my code. 
the scenario I imagine: 
before the test I want to debug I write `Tdd.Debug.enable`
And after the test line I add `Tdd.Debug.print_and_disable`. 
The last line prints a tree of called functions, their arguments and return values. 
We can modify compiler functions.