- From: Brendan Eich <brendan@mozilla.org>
- Date: Fri, 23 Sep 2011 17:58:41 -0700
- To: David Bruant <david.bruant@labri.fr>
- Cc: public-script-coord@w3.org
On Sep 23, 2011, at 5:54 PM, David Bruant wrote: > Le 24/09/2011 02:52, Brendan Eich a écrit : >> On Sep 23, 2011, at 3:53 PM, David Bruant wrote: >> >>> Currently, on Chrome and Opera (12), event attributes are configurable >>> own properties (data in the former, accessor in the latter). >>> Consequently, the freedom to prevent all events to have a "type" or >>> "target" attribute doesn't exist by design. >>> Do anyone miss that freedom? In other words, are there use cases of >>> wanting this freedom at all or is it just a side-effect of putting >>> properties on the prototype and defaulting to configurable=true because >>> a choice has to be made? >> The "own" vs. prototype design is intentional. The non-configurable is too. > What is the rational behind each of these decisions? AIUI, "own" costs a direct property per instance, reified. "prototype" obviously does not. Sorry, I meant to write "configurable", not "non-configurable". Not sure why that's there. A non-configurable prototype property could not be deleted, which would remove the destroy-the-world hazard. It could still be shadowed, but not by assignment -- only by Object.defineProperty. /be
Received on Saturday, 24 September 2011 00:59:08 UTC