Trips me every time

etrepum commented on how hash functions need to be idempotent. I pretty much always interpret things about functions and idempotence incorrectly.

When used in computing, saying a function is idempotent generally means you can call it a hozillion times and the state of the system (& thus the return value of the function) will be the same as if you called it once.

When used in mathematics, a function f is idempotent if f(f(x)) = f(x) for all x. The computing quality of idempotence isn’t useful since f(x) = f(x).

I would greatly appreciate it if we could all find a way to communicate that didn’t involve language.