We present a new type of map called iterable_big_map, which has the scalability property of a big_map, and which can be iterated like a basic map.
This feature was suggested by Nomadic Labs. Thank you to Lucas Feli and Charles Delhinger for the algorithm.
Example
Consider the following declaration of an iterable big map between a nat key and a bytes value:
variable ibm : iterable_big_map<nat, bytes> = []