I wish something like this could trace also data flow in a program.

Something I do have in mind. Do you have an idea of the kind of UX you'd like to see?

	▲	chenshuiluke 3 hours ago \| parent \| next [-]
		I would be interested in this too if you ever build it.
	▲	actionfromafar 3 hours ago \| parent \| prev [-]
		Only naïve ones I'm afraid, such as a heap view.