akka/akka — pull request #1291 by rkuhn (2013-04-01 14:42:19+00:00)
Title: implement and document Pipelines, see #3174

- heavily inspired by spray.io.Pipeline
- fully functional style: a stage returns the resulting commands and
events, which makes it impossible to mess with the pipeline from the
inside
- object allocations are optimized away for emtpy and 1-elem results
- added type-safety, verifying that stages match up
- management commands “from the side” for configuration or async events
- full Java API and docs

also add @throws declaration to actor life-cycle hooks, see ticket 3188