Optimize Scala Code

Make a measured Scala hot path cheaper without changing observable behavior. Each change applies one reference card to a cost that a profile attributes, is proven equivalent by an oracle, and is kept only if the metric the card names improves: JMH time, gc.alloc.rate.norm B/op, a ThreadMXBean byte delta, a javap instruction, or a call count. The cards record preconditions and counter-indications, so read the card before applying a construct. Scala 3 on the JVM is the default; the cards label Scala 2.13, Scala.js, and Scala Native differences.

Workflow