I've long thought it would be neat to make a Factorio mod that lets you represent pieces of data as items that can be passed around and processed by different s

I've long thought it would be neat to make a Factorio mod that lets you represent pieces of data as items that can be passed around and processed by different steps. For multithreaded, message-based programs it could really help one spot problems as the thing runs, e.g. messages never being responded to because someone's output buffer got full.