One of the reasons FP has gotten so popular over the last 15 years is because we've figured out how to handle mutating data and side effects in a way that is co

One of the reasons FP has gotten so popular over the last 15 years is because we've figured out how to handle mutating data and side effects in a way that is compatible with standard FP plumbing. (Though there are probably a few roadblocks here and there that need work.)