def connected_components(node_iterator, possible_moves):
    components = list()
    seen = set()

    for node in node_iterator:
        if node not in seen:
            queue = deque([node])
            component = set()

            while queue:
                current = queue.popleft()
                assert(current not in seen)
                component.add(current)

                for nnext in possible_moves(current) - seen:
                    queue.push(nnext)

            components.append(component)