Batch Strategy

Choose the batch primitive based on the shape of the problem, not on convenience.

Need	Use
Per-item status	mapItems(...)
Fail fast on the first bad item	mapAll(...)
Return every failure	mapCollectErrors(...)
Aggregate existing Result[] fail fast	combine(...)
Aggregate existing Result[] and keep all failures (no successes on failure)	combineAll(...)

Rule of thumb

• validation screens usually want collect-all
• write pipelines usually want fail-fast
• keyed UI errors should stay keyed
• existing Result[] should use combine or combineAll
• combineAll(...) returns only the collected failures when any input fails

Related pages

• Batch processing
• Batch processing reference