You already realized that env vars are an example of dynamic scoping, and someone mentioned exceptions downthread. But pretty much any serious programming lang

You already realized that env vars are an example of dynamic scoping, and someone mentioned exceptions downthread. But pretty much any serious programming language has some (often crappy ad-hoc) implementation of dynamic scoping somewhere, because it's very useful. Take decimal contexts in python -- would you really like to pass number of significant digits and rounding mode to every operation? Sadly, it's also an example of a crappy ad-hoc implementation (broken with async).