NotationMap.Unsafe
val map : (key -> 'a -> key * 'b) -> 'a t -> 'b t
As the usual map, but also allows modifying the key of a binding. It is required that the mapping function f preserves key equality, i.e.: for all (k : key) (x : 'a), compare (fst (f k x)) k = 0.
map
f