doc: define hierarchy and order comparision for use cases
@@ -8,9 +8,16 @@ This folder contains the use cases for `libelektra-core`.
2. associates each key with
1. values: an arbitrary byte sequence
2. metadata: another ordered, hierarchical associative array, which only associates keys with values
-3. orders keys first by namespace then lexicographically
-4. supports the operations: insert, lookup, prefix lookup, access by index and delete
+3. orders keys first by namespace then lexicographically with respect to hierarchy
+4. supports the operations: insert, remove, lookup, prefix/hierarchy lookup and access by index (which enables iteration)
Additionally, `libelektra-core` provides a data structure, called `Key`, that represents a single key-value pair in the associative array, but can also be used standalone.
+To support the hierarchical and ordered nature of a `KeySet` there are two fundamental comparison operations that can be performed on two `Key`s:
+
+1. Order Comparison:
+ Establishes the linear order of `Key`s and thereby defines the iteration order of a `KeySet`.
+2. Hierarchy Comparison:
+ Establishes the hierarchy of `Key`s, by defining based on their names whether one `Key` is a descendant of another.
+
The individual use cases provide details on these data structures and the operations it supports.
