[C++][Dataset] Provide Scanner methods to yield/visit scanned batches #27648
Description
From discussion in #27634
It'd be useful to consumers of Scanner to receive an iterator of scanned record batches or apply a visitor to batches as they are scanned without handling ScanTasks. For example, this could enable aggregations or other computations which don't require the entire table to be materialized.
Reporter: Ben Kietzman / @bkietz
Assignee: Ben Kietzman / @bkietz
Related issues:
- [C++][Dataset] Scanner::TakeRows should push down the query if possible (is related to)
- [GLib][Ruby][Dataset] Remove bindings for internal classes (is related to)
PRs and other links:
Note: This issue was originally created as ARROW-11797. Please see the migration documentation for further details.