The fundamental difference between FP and imperative/OO is that in FP, equality is easy, state is hard. In imperative and OO, the opposite is true. The restric

The fundamental difference between FP and imperative/OO is that in FP, equality is easy, state is hard. In imperative and OO, the opposite is true. The restrictions that are in FP are there because it comes from the standpoint that equality should be easy. In a parallel paradigm, state is hard, period. You look at how people use Spark, for example, and it's kind of funny that they are effectively doing FP using an imperative language.