[BEAM-6255] Support emit func output in the Go SDK's CombineFn ExtractOutput

• Type: New Feature
• Status: Open
• Priority: P3
• Resolution: Unresolved
• Component/s: sdk-go
• Assignee: Unassigned
• Reporter: Robert Burke
• Created: 18/Dec/18 00:00
• Updated: 03/Jun/22 23:40

Description

When taking a sample or other filter, it consider supporting emitting values with an emit func from the accumulator rather than extract a single value. Otherwise general accumulators tend to go through awkward reflective code to construct the slice.

Either the single value return or an emitted return should be supported.