Re: Enlightenment via avoiding the T-word

[Tim Bray <tbray@textuality.com>]

At 09:44 PM 29/08/01 +1000, Rick Jelliffe wrote:
>Either way doesn't change the point.  If you have a script written
>(using names not vapor-PSVI)
>under the assumption that there are no local types (or, at least, 
>a known set of local types, the others being global, and the
>local type not being a compatible restriction of the global type), then
>introducing local types forces you to do some more programming
>to fix it.  It is not robust.

Hmm, I'm not willing to go nearly as far as Rick.  But he's done
a good job of pointing out that overloading names in a single
markup vocabulary does have a real cost, and one you should 
worry about (and I found it instructive that in the RDBMS world, 
ERWIN raises a flag on this).

On the other hand, when I'm writing O-O software, when I pick
variable and method names I don't worry very much about whether 
they clash with locals elsewhere.  Hold, on that's not true: if 
you're building a class in Java, you'd better not have a toString() 
method that launches missiles :)... but it's certainly a different 
style of thinking.

There's scope for a nice general essay here about the 
differences between ways of thinking about data; basic WF XML, 
OOP, and RDBMS represent instructively different thought 
patterns.  PSVI and DTDs and SOAP and so on fit into this 
pattern in interesting ways.  -Tim