> 5. Let inherited be the result of calling the [[GetProperty]] internal method > of proto with property name P.
Gah, [[GetProperty]] not [[GetOwnProperty]] -- and we don't care about prototype extensibility? (i think we came to that conclusion in redmond?) --Oliver On Sep 14, 2012, at 7:05 PM, Brendan Eich wrote: > Oliver Hunt wrote: >> My reading of [[CanPut]] implies that it only checks a single level of the >> prototype chain. This seems incorrect to me but I thought I'd check whether >> it is in fact intentional, or whether it's a spec bug. > > See step 4 and later. > > /be > > ES5.1 8.12.4 [[CanPut]] (P) > > When the [[CanPut]] internal method of O is called with property name P, the > following steps are taken: > > 1. Let desc be the result of calling the [[GetOwnProperty]] internal method > of O with argument P. > 2. If desc is not undefined, then > a. If IsAccessorDescriptor(desc) is true, then > i. If desc.[[Set]] is undefined, then return false. > ii. Else return true. > b. Else, desc must be a DataDescriptor so return the value of > desc.[[Writable]]. > 3. Let proto be the [[Prototype]] internal property of O. > 4. If proto is null, then return the value of the [[Extensible]] internal > property of O. > 5. Let inherited be the result of calling the [[GetProperty]] internal method > of proto with property name P. > 6. If inherited is undefined, return the value of the [[Extensible]] internal > property of O. > 7. If IsAccessorDescriptor(inherited) is true, then > a. If inherited.[[Set]] is undefined, then return false. > b. Else return true. > 8. Else, inherited must be a DataDescriptor > a. If the [[Extensible]] internal property of O is false, return false. > b. Else return the value of inherited.[[Writable]]. > > Host objects may define additional constraints upon [[Put]] operations. If > possible, host objects should not > allow [[Put]] operations in situations where this definition of [[CanPut]] > returns false. _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
