extracting namespace from a property
brendan at mozilla.org
Thu Mar 1 12:52:40 PST 2007
On Mar 1, 2007, at 7:01 PM, Yuh-Ruey Chen wrote:
> So a classes' prototype is always going to be mutable?
> In chapter 9, I see "Prototype objects are always instances of the
> dynamic class Object and therefore can always be extended by the
> addition of dynamic properties. Unlike with function closures which
(Note to Francis: "function closures" here is wrong, it should be
> a prototype property that is a variable and can be reset to another
> object, classes have a prototype that is read-only and so always
> to the same object."
> which to me says that although the prototype property is read-only for
> classes, the referenced prototype object can still be mutated.
Right, when a property is described as read-only (or enumerable, or
whatever), it's the attribute of the property (slot attribute, if you
like), not the value (referent for an object type) that's being
> It only becomes an issue once a custom enumerable qualified
> property is
> added by the author. So maybe we should let typeof name ===
> "object" and
> just warn developers to use |is| if they intend to enumerate over
> objects with enumerable qualified properties.
Ok, that was my original position. Thinking about it, the only hazard
is if one is migrating a large body of JS1 code to JS2, adding
namespaced public properties to objects in the new code, but letting
such objects flow into old code's for-in loops that assert or require
typeof id == 'string'. We can make that a "fix as you find" case.
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