Judy Array - Terminology

Terminology

Expanse, population and density are commonly used when it comes to Judy. As they are not commonly used in tree search literature, it is important to define them:

1. Expanse is a range of possible keys, e.g. 200, 300, etc.
2. Population is the count of keys contained in an expanse, e.g. 200, 360, 400, 512, 720 = 5
3. Density is used to describe the sparseness of an expanse of keys: Density = Population/Expanse