gistfile1.txt

# Normally, iterators must be passed all their arguments each time they are iterated over
iterator counter(start, stop:int): int {.closure.} =
  var x = start
  while x < stop:
    yield x
    inc(x)

var counterInstance = counter
echo(counterInstance(0,5))
echo(counterInstance(0,5))
echo(counterInstance(0,5))
echo(counterInstance(0,5))
echo(counterInstance(0,10))
echo(counterInstance(0,10))
echo(counterInstance(0,10))
echo(counterInstance(0,10))

# Heres a python equivalent (note the lack of explicit args each iteration)
def counter(start, stop):
    x = start
    while x < stop:
        yield x
        x += 1

counterInstance = counter(0, 5)
print(counterInstance.next())
print(counterInstance.next())
print(counterInstance.next())