At one time in my life I played with the prospect of becoming an airport manager, to the point of buying some expensive books (OK one book) on the subject and reading up in Florida (Bradenton, Golf Lakes Estates), between other jobs.
I do like the postit metaphor, but have trouble visualizing going around a busy airport putting post-its on ticket counters, security apparatus, flight attendants, and not getting in trouble. On the other hand, with a textbook open, an airport depicted, I'm very used to pointers in the sense of arrows, usually labeled, call them tags or handles. Anatomy books, same thing, pointers to ribosomes, close-ups of DNA or whatever. So just to use our own OO jargon, I'd say sticky post-its are a subclass of the tag or handle concept. Descending the same tree along other branches, we get to my dog leash metaphor (the first ring of which came from a coffee cup (another idea of "a variable") in some "Youtoon" awhile back). Back to the airport, what we want students to realize is that multiple namespaces might be about the same complex institution or knowledge domain, but hey, we *don't* want to import all this complexity willy-nilly, but with an eye towards getting very specific work done. Namespaces are *designed* (more or less intelligently) for a specific *purpose*. They're the antithesis or random inventories of stuff, in most cases. And keep in mind what namespaces map: not just static data. You can fire up a jet engine, switch on the radar, start and stop elevators. A namespace is like some Lawn Mower Man fantasy, except in a more manageable and sustainable form. Yes it's about control, we're not apologetic about that. Engineering is engineering in that respect. So in one namespace it's all about baggage handling, in another all about queuing in ticket lanes, in another all about food services along the concourse, surveillance cameras (who's pigging out) -- haven't even mentioned the airplanes yet, or the runways. So many namespaces! This gets across to the beginner that we're free to tag as we please, going into a situation, and there's nothing illogical or inherently confusing about multiple namespaces using the same objects concurrently. That's how we work in the real world as human beings: as players operating in parallel within a shared environment. OO (an invention, a style of thinking) has always been about letting us think naturally, in ways already familiar to us, independently of any computer or science. We need to think about threads within processes on a given computer, sure, but also about concurrency within our respective knowledge domains, and this idea of many namespaces sharing access to a busy airport, each supporting a point of view, or job description, is going to help with many a future programming challenge. Kirby On Thu, May 22, 2008 at 9:15 AM, Winston Wolff <[EMAIL PROTECTED]> wrote: > Using the post-it note metaphor, it might be better to say: > > x = y is the same as creating a new bookmark called "x" which represents "y" > > -ww > > On May 21, 2008, at 9:13 PM, kirby urner wrote: > >> x = y involves "emailing" an URL from y to x, setting up a second >> alias. Recipient x now has a copy of the same URL as y, but no website >> got copied. > > Winston Wolff > Stratolab - Kids exploring computers, comics, and robots > (646) 827-2242 - http://stratolab.com > > _______________________________________________ Edu-sig mailing list Edu-sig@python.org http://mail.python.org/mailman/listinfo/edu-sig
