Huh, that’s an interesting point, and I’d have to think on that. There are still plenty of cases where ordering would matter, like subtract(a,b), unless you go whole hog and define that like

  fn sub(a:LeftOp, b:RightOp)

but that seems redundant. There are still plenty of other cases where I could your idea being useful. Like I always forget whether (in Python) it’s json.dump(file, data) or dump(data, file). Ultimately, should it matter? I’m passing a file handle and an object, and it’s unambiguous how those two args relate to the task at hand.