Untitled

iterator process(a: var seq[int], setZero: var bool): int =
  for i in mitems a:
    yield i
    if setZero:
      setZero = false
      i = 0

var a = @[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
var sz = false

for i in process(a, sz):
  if i mod 2 == 0: sz = true
echo a