> > [snip] >
> ES5.1 clause 8.6.2 says: > > "The value of the [[Class]] internal property of a host object > may be any String value except one of "Arguments", "Array",..." > > In other words, host object provides (such as a DOM implementation) are > not allowed to define new kinds of objects whose [[Class]] is Array. > > It's fine to want to define a new kind of host object that is > behaviorally very similar (but slight different) from instances of the > built-in Array constructor. But characterizing such objects by saying they > have [[Class]]=="Array" > > is a not meaningful from a ES5.1 specification perspective. > > I'm fine with any formulation, as long as it gives the correct behaviour > in cases like Array.prototype.concat and Array.isArray. > ES 5.1 15.4.3.2 Array.isArray() ... 2. If the value of the [[Class]] internal property of arg is "Array", then return true. ... Considering Allen's previous comment, this is not going to be allowed. Rick > > Do you have suggestions for what to write? > > / Jonas
