A post by Simon Garland, Chief Strategist, Kx Systems.
Aeons ago, when learning APL, the FinnAPL Idiom list was absolutely invaluable. A little blue book published by the Finnish APL Association containing about 600 hand-polished APL idioms.
This was in the days before the internets or iPhones – it was portable and it was THE REFERENCE. Dragged around in my rucksack for years, scribbled on by kids, and used as a notepad when nothing else was available.
Years later Eugene McDonnell took that list and ported it – or those that made sense – to k. The original text lived quietly on the kx.com website for many years but slid out of sight as q took the limelight.
Until … out of the blue Jay Han emailed saying that he’d ported (re-ported) the list from k to q as part of his path to learning q – and were we interested in putting it on code.kx.com? We sure were. It’s been there for some years now, but I’ve noticed that few people make much use of it as the one -l-o-n-g- page format isn’t really accessible.
So when this site came along I thought that reposting the individual idioms in homeopathic doses would be a good way to raise the visibility of the code beyond the first couple of browser screens. Having a pile of idioms hardwired into your fingers has always been looked on as an essential part of getting comfortable with any of the array languages q, k or APL – I hope this epic series will help new users. Some of the more snappy idioms may even end up tweeted if I can see a way to avoid anything containing the # symbol turning into a bizarre hashtag.
UPDATE: follow or add your own tweets to #qidioms