> -----Original Message----- > From: Waldemar Horwat [mailto:[EMAIL PROTECTED] > Sent: 10. mars 2008 18:50 > To: Lars Hansen > Cc: es4-discuss@mozilla.org > Subject: Re: ES4 draft: Object > > > intrinsic function propertyIsEnumerable(name: EnumerableId, flag: > > (boolean|undefined) = undefined): boolean > > I too find the second parameter here abhorrent. Please find > another way to solve it (Brendan's namespace idea maybe) or > remove this feature altogether.
The feature was approved by the WG and solves a practical problem. If another way to solve this practical problem is proposed (in a more structured form than in the ongoing discussion) and finds favor with the WG, then fine -- of course we can replace it. Until then, this feature stays as it is until the WG can be convinced that it needs to be removed. Personally I think that "it is ugly/abhorrent" is a weak basis on which to remove the current feature. > How does property lookup deal with properties indexed by > numbers that are not int or uint? toEnumerableId converts > them to strings, but the Vector proposal indicated that > vectors don't. The intrinsic::hasOwnProperty and intrinsic::propertyIsEnumerable methods on Object require EnumerableId parameters, and no conversion happens automatically when they are called (there should be no automatic conversion to union types, even from a number to a number in the type). So programs trying to call the intrinsic methods on doubles (say) will receive errors. This is true independent of Vector. The prototype methods inherited from Object perform conversions explicitly, but can be overridden in Vector to prevent the conversion. Ergo the hasOwnProperty and propertyIsEnumerable methods on Vector should be able to handle arbitrary names, and should return "false" for all property names that are numbers not in the uint range -- if that's what we think is the desired behavior. That said, you raise a good point and I don't think the story is fully coherent yet. Certainly we don't have a working prototype of this. (And yet another point is that I expect that the int and uint types are not going to be in the final language and that some of the machinery in Object will have to be rethought as a consequence of that change.) --lars _______________________________________________ Es4-discuss mailing list Es4-discuss@mozilla.org https://mail.mozilla.org/listinfo/es4-discuss
