On Fri, May 27, 2011 at 5:45 AM, Tom Van Cutsem <[email protected]> wrote: >> I tend to agree with David about having a separate observable API, if that >> is indeed the driving use case. That API can be very similar to the Proxy >> API though. Racket's "chaperones" come to mind: a chaperone is a strictly >> less powerful kind of proxy, one that is not allowed to arbitrarily change >> the result of the original operation (and IIRC, a chaperone also cannot stop >> the original operation from taking place on the target object). > > Spoke too soon: from > <http://web.mit.edu/drracket_v501/share/racket/doc/reference/chaperones.html> > I learn that chaperones can throw exceptions, and thus presumably abort an > intercepted operation early. Still, the idea of a "tamed" kind of proxy is > worth exploring.
I believe that the semantics of observers allow for throwing exceptions, and thus terminating an operation, at least according to the wiki page. -- sam th [email protected] _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
