These optimize out unnecessary code duplication, reserve vector capacity beforehand by leveraging `Iterator`s and avoid unnecessary double-lookups into HashMaps.
Reviewed-on: https://codeberg.org/topola/topola/pulls/128
Co-authored-by: Alain Emilia Anna Zscheile <fogti+devel@ytrizja.de>
Co-committed-by: Alain Emilia Anna Zscheile <fogti+devel@ytrizja.de>