Some Typed Objects Confusion

Andrea Giammarchi andrea.giammarchi at
Tue Aug 20 18:20:57 PDT 2013

Uhm, just a couple of extra question about that page if/when you have time:

   1. string and boolean are mentioned, but nowhere in your `struct.js`
   prolyfill code. Will string and boolean be accepted?
   2. `Object` and `Any` are mentioned, but exported as object and any in
   your `struct.js` prolyfill example. W
   3. Which is the right way?

The reason I am asking is to be able to create code that does absolutely
nothing (for performance reason) but will look like the real thing so I can
start experimenting with static structures and possibly a develop VS
production version of an ES3 to ES5 compatible polyfill since I believe
your code won't run anywhere except in SpiderMonkey (which is OK but it's
not suitable for a lightweight migration to "structure like" logic)


On Tue, Aug 20, 2013 at 4:55 PM, Andrea Giammarchi <
andrea.giammarchi at> wrote:

> Awesome, thanks!
> On Tue, Aug 20, 2013 at 4:12 PM, David Herman <dherman at> wrote:
>> On Aug 20, 2013, at 1:31 PM, Andrea Giammarchi <
>> andrea.giammarchi at> wrote:
>> > [In this page](
>>, and in
>> the latest meeting note too, I can read both uint8 and Uint8, as example.
>> Bug. Fixed, thanks.
>> > **The Question**
>> > How is `new StructType({x:Uint32, y:Uint32})` supposes to understand
>> the type? `instanceof Uint32` or `typeof v === "uint32"` or ... both in
>> case of `boolean` and `string` ?
>> Neither. It tells you that the x and y fields have typeof 'number' and
>> that their values are constrained to be integers in the range [0, 2^32).
>> > A bonus question would be: does anybody know when this stuff is planned
>> to go out? Not a single beta/alpha channel is exposing anything at all so
>> far.
>> Nikhil Marathe and Niko Matsakis are actively working on the
>> implementation for SpiderMonkey:
>> Dmitriy Lomov is actively working on updating the prollyfill to match the
>> current API:
>> Not sure if anyone on the V8 team (which includes Dmitriy) has started
>> implementation but I believe they're interested. Right now Dmitriy is
>> focused on the prollyfill and spec.
>> Dave
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