>Very few languages, even in the functional world, have such a strict separation. It's catching on. Nim has the noSideEffect pragma (enabled by default if a fu

>Very few languages, even in the functional world, have such a strict separation. It's catching on. Nim has the noSideEffect pragma (enabled by default if a function is defined with "func" rather than "proc"), and D has a "pure" annotation. Both are compiler-checked.