template chain(iter1, iter2: typed, body: untyped) = block: for v {.inject.} in iter1(): body for v {.inject.} in iter2(): body iterator thing1: string = yield "A" yield "B" iterator thing2: int = yield 1 yield 2 chain(thing1,thing2): when v is string: echo("String: ", v) elif v is int: echo(v + 5)