Sjoerd Visscher's weblog

My ideas about new web technology that can change the future of the world wide web.

< Wednesday, March 06, 2002 >

Type filtering?

In the long run the scripting culture has to win.  Tightly coupled and brittle interfaces aren't particularly enduring.  We also need a protocol which enables people to initially develop simple interfaces and then gradually evolve them to be more adaptive without breaking deployed clients and servers. [Sam Ruby's Radio Weblog]

I could not agree more with this. The software world is becoming more dynamic, not less. We need more runtime tools. Here's some interesting reading along those lines. [Patrick Logan's Radio Weblog]

We need more freedom, that's true. But type freedom the way Javascript has is not the solution. Type filtering is something I'm looking for. In a far from perfect way this is possible in XSLT. For example a template that requires an x element with an a subelement, would have a match="x[a]" attribute. If then later x elements need more subelements, the template won't break. And if the template needs a subelement, say b, you change the match to match="x[a][b]". And then x elements without b will simply not match anymore. There's no "b is not defined" error.