InfoQ: Clojure 1.1 Adds Transients, Chunked Sequences for Efficiency - at the moment, Clojure is seeing the more interesting optimizations and considerations for functional programming. Because they focus on the essential part: data structures. An often neglected area in other languages - what good is a functional language if the included data structures are simply too low-level? Clojure provides access to low-level elements from Java if necessary for performance reasons, but also high-level data structures that behave much more naturally in functional code. And with chunked sequences and transients, now two quite elegant optimizations for these, which help avoid descending into the Java depths.