Yea, agreed that we want to provide some comfort too.
I'm thinking of a helper module with `jump'` `fold_range` and `fold_rev_range` a la the helper module in Simple_store
Currently the one in simple_store works against Simple_store.t types and it allows iterating all keys, not just the public keys like this one does... so it requires some (small) changes.
Anyway, I'll have a look tomorrow.