{"id":"null-iterator-always-done","text":"A NullIterator whose IsDone always returns true enables uniform traversal of Composite structures by eliminating the need to special-case leaf nodes that have no children to iterate.","truth_value":"IN","source":"entries/2026/06/17/gof-oo-chunk-17.md","source_url":"","source_hash":"","justifications":[],"dependents":["null-iterator-enables-composite-transparency","null-iterator-propagates-transparency-cost-across-pattern-boundaries","null-object-meta-pattern-in-strategy-and-iterator"],"metadata":{"last_premise_reviewed":"2026-06-17T18:19:22","premise_review_result":"pass"},"created_at":"2026-06-17T21:30:28+00:00","updated_at":"2026-06-17T21:30:28+00:00","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"null-iterator-always-done","truth_value":"IN","reason":"premise"}]}}