Iterator Pattern

Provide sequential access to collection elements without exposing underlying structure. In C, typically a struct with next() function or index-based traversal.

ikigai Application

Scrollback traversal: Iterate visible lines for rendering without exposing ring buffer internals.

Message iteration: Walk session messages for LLM context building.

Implementation options:

// Index-based (simple)
for (size_t i = 0; i < scrollback->count; i++) { ... }

// Iterator struct (encapsulated)
ik_iter_t *iter = ik_scrollback_iter(scrollback);
while (ik_iter_next(iter, &line)) { ... }

Current approach: Index-based iteration is sufficient. Iterator struct adds value when traversal logic is complex or needs to hide internals.