I think something that is impure when it needs to be is easier for me to maintain than something that really goes out of its way to be pure. Especially when the

I think something that is impure when it needs to be is easier for me to maintain than something that really goes out of its way to be pure. Especially when the set of cases something should handle is large. On the other hand, I think that immutable data is rarely difficult to deal with, and saves my stupid self from all kinds of bugs that I'd probably write.