> All the examples are Java 9, Scala, Groovy, or Clojure Some of those languages are more functional than others. I'd put them on a scale from least functional

> All the examples are Java 9, Scala, Groovy, or Clojure Some of those languages are more functional than others. I'd put them on a scale from least functional to most like so: Java 8 (least functional) Apache Groovy Java 9 Scala Clojure (most functional)