Our framework generates, compiles, and runs search methods in which we attempt to perform lookup optimisations.
When the search is over a collection that has multiple keys with varying key sort orders, this becomes quite a difficult exercise.
The ability to easily access the types of keys, and the key type's low and high values, would be extremely useful.
The MergeIterator class had a similar difficulty which required the internal creation of appropriate key type low and high values. See PAR 66511 closure.
Our framework currently uses a combination of the CollClass getKeys method for key information, and class property information for type information, when building the search.
The ability to ask a key for type information would greatly simplify the work, and the ability to ask a key for the it's low and high values would be hugely beneficial in the generation of searches.