This ticket proposes to introduce a public interface that imposes a total ordering over the keys of a (ReadOnly)StringMap. This interface views all key-value pairs as a sequence ordered by key, and allows keys and values to be accessed by their index in the sequence.
The intention is to let SortedArrayStringMap implement these interfaces. (It already implements the necessary methods; the visibility of these methods will change from package-protected to public.)
These interfaces help reduce log4j's dependency on the JDK Map interface: the JDK Map interface does not provide a garbage-free way to iterate over all its keys or key-value pairs.
For example, these interfaces can be used to make MapFilter and its subclasses garbage-free, and reduce allocation of temporary objects in MapMessage and subclasses.