On 5/8/16, 1:18 AM, "Harbs" <harbs.li...@gmail.com> wrote:
>I’m still having trouble with the spec, though. The spec has the >following in [[Append]]: > >3. If Type(V) is XMLList, > a. Let x.[[TargetObject]] = V.[[TargetObject]] > b. Let x.[[TargetProperty]] = V.[[TargetProperty]] > c. Let n = V.[[Length]] > d. If n == 0, Return > e. For j = 0 to V.[[Length]]-1, let x[i + j] = V[j] > >Step e uses bracket assignment to the XMList of the values in the >right-hand object. As I understand it, bracket assignment inserts the >object into the target object as well. I think that’s what it says in >[[Put]], but I’m not sure. Of course, with my understanding, a and b >should be after step e. So, I’m somewhat confused there... Can you be more specific about what text makes you think the bracket assignment inserts into the targetObject? I'd say that other parts of the spec are more explicit about calling [[Put]] and other methods and that bracket syntax is just assigning values to the internal object for XML and XMLList. > >Either way, I think we need to add a plus() method to XML and XMLList >which does “the right thing” as described by 11.4.1 in the spec. > >I’m also not sure every case of addition is being handled correctly: > >1. Number + XML/XMLList >2. XML/XMLList + Number >3. String + XML/XMLList >4. XML/XMLList + String >5. XML/XMLList + XML/XMLList Well, concat() is currently what is output. It might be only used where you would want to use plus(). But I had a not-so-nice thought: Maybe we need to rewrite our XML implementation. I am feeling like we made a mistake making up our own method names thinking that we understood the 'semantics' of E4x. It might be that we need to have you implement [[Put]] [[Append]], etc. and have the compiler generate the algorithms described in the spec. This would void your suggestion for adding a foreach() method. Our current codegen expects the return of an object to iterate which is what the E4x spec says to do. This would be a significant amount of work, but might be for the best. Thoughts? -Alex
