Status: IN
Iterator design decomposes along two orthogonal axes: the control axis determines who drives traversal (external iterators giving clients step-by-step control vs. internal iterators encapsulating the loop), while the concern axis separates the traversal mechanism from the action performed at each element — yielding four quadrants of iterator design.
Two independently described Iterator design dimensions (control placement, concern separation) form a two-axis design space
Depends on (SL): external-vs-internal-iterator-flexibility-tradeoff, traversal-and-action-orthogonal-concerns