Thanks for your reply. I filed this issue to bugs.ecmascript.org https://bugs.ecmascript.org/show_bug.cgi?id=415
Regards, Yusuke Suzuki On Sun, Jun 24, 2012 at 11:59 PM, Allen Wirfs-Brock <[email protected]>wrote: > this also should be reported to bugs.ecmascript.org > > This is a very good catch. > > Allen > > > > On Jun 24, 2012, at 6:45 AM, Yusuke Suzuki wrote: > > Hello everyone, > > In 15.4 ArrayCreate algorithm step 7, we use [[DefineOwnProperty]] of A. > > Call the [[DefineOwnProperty]] internal method of A with arguments >> "length", Property Desciptor {[[Value]]: length, [[Writable]]: true, >> [[Enumerable]]: false, [[Configurable]]: false}, and false. > > > ArrayCreate set A's [[DefineOwnProperty]] to 15.4.5.1 method in step 4, so > step 7 calls 15.4.5.1 Array's [[DefineOwnProperty]]. > > Array's [[DefineOwnProperty]] assumes that 'length' property is always > set. Seeing 15.4.5.1 step 1 > > Let oldLenDesc be the result of calling the [[GetOwnProperty]] internal >> method of A passing "length" as the argument. The result will never be >> undefined or an accessor descriptor because Array objects are created with >> a length data property that cannot be deleted or reconfigured. > > > But, in ArrayCreate phase (step 7), A's 'length' property is not set yet. > Then assertion in 15.4.5.1 step 1 always fails. > > So we should use the default [[DefineOwnProperty]] internal method instead > of Array's. > I suggest modifying ArrayCreate step 7, > > Call the default [[DefineOwnProperty]] internal method (8.12.9) on A with > arguments "length", Property Desciptor {[[Value]]: length, [[Writable]]: > true, [[Enumerable]]: false, [[Configurable]]: false}, and false. > > Regards, > Yusuke Suzuki > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > > >
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