Haven't the faintest. I don't speak Haskell, 's why I asked. I'd thought pureness was a property of function definitions, irrespective of what they get passed,

Haven't the faintest. I don't speak Haskell, 's why I asked. I'd thought pureness was a property of function definitions, irrespective of what they get passed, but living in Javascript land I've never had occasion to be concerned with the distinction. I kind of suspect it's not really something that's useful to talk about.