- From: Mark Baker <distobj@acm.org>
- Date: Wed, 26 Jun 2002 08:02:07 -0400
- To: Miles Sabin <miles@milessabin.com>
- Cc: w3arch <www-ws-arch@w3.org>
Hi Miles, On Wed, Jun 26, 2002 at 10:06:04AM +0100, Miles Sabin wrote: > Mark Baker wrote, > > The Web is really late bound, because you don't know what you're > > dealing with until after you've invoked GET (most commonly - there > > are other ways). For example, if I gave you any URI, you wouldn't > > know what it identified until you entered it into your browser. > > Hmm ... interesting, that's not quite the way I'd have characterized the > late/early distinction. > > Your contrast seems to be analogous to the difference between, > > class HTTPServer > { > public Object GET(); // Late > } > > and, > > class HTTPServer > { > public SomeSpecificType GET(); // Early > } That wasn't my intent. More below ... > whereas the traditional OO constrast is between, > > class HTTPServer > { > public Irrelevant GET(); // Late > } > > and, > > class HTTPServer > { > public final Irrelevant GET(); // Early > } IMO, the traditional component-versus-object contrast is; class WWW-Service { public Something GET(); ... } versus class My-Stock-Quote-Web-Service { public Something GetStockQuote(); ... } The "type" here is at the class/interface level, not the method/response level. So in the former case, a client discovers that the thing is a stock quote *after* invoking GET, whereas in the latter case, the client needs to know that it's a stock quote *before* invoking GetStockQuote(). > I wonder if this different understanding of early/late has any bearing > on your insistence that HTTP satisfies the "no a priori knowledge" > constraint. I've always found that baffling, because there clearly is a > priori knowledge if we understand early/late in the traditional way: we > know up front that the result of a GET will be an entity (even if we > don't know the details of how it's produced). What I meant by the "no a priori knowledge" constraint is that HTTP doesn't require me to know that something is a stock quote in order to retrieve it (or change it, or hand it some data, etc..). Does that help explain my previous ramblings? 8-) MB -- Mark Baker, CTO, Idokorro Mobile (formerly Planetfred) Ottawa, Ontario, CANADA. distobj@acm.org http://www.markbaker.ca http://www.idokorro.com
Received on Wednesday, 26 June 2002 07:51:38 UTC