>-----Original Message----- >From: Brendan Eich [mailto:[email protected]] > >> BTW, I haven't yet perceived that we have consensus on putting this >> into ES5. My interpretation of Brendan's initial comments on the >> matter was that he was opposed to it for ES5. (I'm sure he'll let >> us know whether or not that is correct). > >It's late in the game, but a sentence about [[Prototype]] seems >doable. I defer to you on this, since you're Editor and it'll fall >upon you to draft the change. >
OK, I'll put it in. Here is what I am inserting into section 8.6.2 following the paragraph about [[Prototype]] that comes immediately after table 4: Every ECMAScript object has a Boolean-valued [[Extensible]] internal property that controls whether or not named properties may be added to the object. If the value of the [[Extensible]] internal property is false then additional named properties may not be added to the object. In addition, if [[Extensible]] is false the value of the [[Prototype]] internal property of the object may not be modified. Once the value of an [[Extensible]] internal property has been set to false if may not be subsequently changed to true. NOTE This specification defines no ECMAScript language operators or built-in functions that permit a program to modify an object's [[Prototype]] internal property or to change the value of [[Extensible]] from false to true. Implementation specific extensions that modify [[Prototype]] or [[Extensible]] must not violate the invariants defined in the preceding paragraph. Notice that I also made sure that [[Extensible]] cannot go from false to true which was also previously unstated in the specification. Allen _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
