A long time ago I wrote a conditions system for python: https://code.google.com/archive/p/pyconditions/ https://code.google.com/archive/p/pyconditions/ I would

A long time ago I wrote a conditions system for python: https://code.google.com/archive/p/pyconditions/ https://code.google.com/archive/p/pyconditions/ I wouldn't recommend using it, but it is an interesting error/control model, and I always wondered why it hasn't seen wider implementation - I presume because it is closer to the "dangerous" end of the power spectrum.