>-----Original Message----- >From: [email protected] [mailto:es-discuss- >[email protected]] On Behalf Of Jeff Walden >Sent: Monday, June 08, 2009 6:14 PM >To: [email protected] >Subject: More [[DefineOwnProperty]] > >In Array's [[DefineOwnProperty]], what is the rationale for calling the >default [[DefineOwnProperty]] with a Throw argument specified as false, >rather than the Throw provided to the initial call?
False is passed because this call will always succeed if all the other invariants of the specification are maintained. Arguably a clarifying note might be a good idea or Throw could be passed with on net change to the semantics. > >In step 6, does "same value" mean the SameValue spec operation? If so >the expected notation should be used here. Yes, SameValue is the intent and yes it should be written that way in the spec. > >Since no property is guaranteed to be present, by the time we reach step >7, we cannot rely on every property of Desc being present. How then >should 7a be interpreted if [[Configurable]] was missing from Desc, If [[Configurable]] is missing then it certainly is not true. >or 7b if [[Enumerable]] is missing from Desc, If [[Configurable]] is missing then it can not be the Boolean negation of the [[Configurable]] field of current. >or 10a(i) if [[Writable]] is absent from Desc? If [[Writable]] is missing then it is not true. The specification incorrectly assumes each is >actually present in the property descriptor. No, but since it appears to be a source of confusion it may be worthwhile clarify the language of the specification in this regard. >I believe these last concerns only further demonstrate why standalone >[[Configurable]]/[[Enumerable]]/[[Writable]] modifications should be >removed to their own method rather than leaving them in >Object.defineProperty, as I requested in a previous thread. The conclusion is based upon a false premise. Regardless, it would be take a much broader base of concern to substantially change the Object reflection API at this point in the release process of ES5. Allen _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
