Perhaps <https://github.com/timotheecour/Nim/issues/378> (see my versions at the end) can be useful for you. I have used it for highly recursive iterators.
- Recursive iterator to unpack arbitrarily nested sequence nocturn9x
- Recursive iterator to unpack arbitrarily nested sequence shirleyquirk
- Recursive iterator to unpack arbitrarily nested sequ... nocturn9x
- Recursive iterator to unpack arbitrarily nested ... HJarausch
- Recursive iterator to unpack arbitrarily nes... nocturn9x
- Recursive iterator to unpack arbitraril... doofenstein
- Recursive iterator to unpack arbitr... demotomohiro
- Recursive iterator to unpack ar... jyapayne
- Recursive iterator to unpack ar... demotomohiro
- Recursive iterator to unpack ar... shirleyquirk
- Recursive iterator to unpack ar... cblake
- Recursive iterator to unpack ar... jyapayne
