Thanks for your comments. Currently I don't have enough experience in Nim - I am still learning. And since I am still convinced that iterators should upgrade from second class citizens to first class citizens in Nimland, tricky macros are not a solution.
For a pull request concerning the compiler I would have to acquire a lot of expertise in Nim's compiler's internals. And I have seen very convincing pull requests which have a hard time to get accepted. This is not at all encouraging.
