aviflax/rollups — pull request #1 by swannodette (2012-02-27 03:47:35+00:00)
Title: Perf

The reason your Clojure version was slower than the CoffeeScript was mostly your use of last - last is always linear in the length of the collection. I added a couple of other modifications - this version is considerably faster than the CoffeeScript version: a 1m window in Clojure takes ~5 seconds, the same window in CoffeeScript is ~35 seconds.