moveNext method
Implementation
bool moveNext() {
while (_stack.isNotEmpty) {
final frame = _stack.last;
if (frame.nextChild >= frame.node.children.length) {
_stack.removeLast();
continue;
}
final child = _pushNextChild(frame);
_stack.add(child.$2);
_current = child.$1;
return true;
}
_current = null;
return false;
}