Binary Data types in window context (was Some Typed Objects Confusion)

K. Gadd kg at luminance.org
Wed Aug 21 10:42:43 PDT 2013


<moving back onto list>

It might be worth doing. On the one hand, I don't really feel like these
names *should* collide with anything, but it seems like the risk is kinda
high... and it's a little weird seeing them in global scope and having to
figure out that they're actually types for binary data and not, for
example, the constructor for boolean or some sort of value type ctor.

Once 64-bit signed/unsigned ints are in will there be two names for those
as well? I.e. Uint64(...) produces one of the new 64-bit unsigned ints,
while uint64 is the name you use when creating a StructType to specify the
type of a field?

If the type names used by binary data actually work as constructors to get
an instance of that type, that might make it more justified for the names
to be in global scope, but that seems like probably unmerited scope creep.

Having the types be in a single 'BinaryTypes' namespace or something at
window-level seems like it would be pretty reasonable; if you're going to
be referring to types a lot you can pull them into locals, or use 'with' in
a gross non-strict function (yuck yuck yuck)

I assume specifying type names as strings, i.e. { field: "uint32" } was
considered and ruled out (it would definitely be strange to mix that with
passing in actual StructType instances).

-kg

On Wed, Aug 21, 2013 at 10:36 AM, Dmitry Lomov <dslomov at chromium.org> wrote:

> On Wed, Aug 21, 2013 at 6:50 PM, K. Gadd <kg at luminance.org> wrote:
>
>> Does this mean the addition of binary data to a browser defines dozens of
>> new names in 'window' scope, like 'string' and 'boolean' and 'uint32'
>> alongside existing names? That's kind of surprising to me (though I can
>> understand why it might be necessary)
>>
>
> Yes, this is where we are at now.
> Maybe we should pack the whole thing into a module.
>
> Dmitry
>
>
>>
>>
>> On Wed, Aug 21, 2013 at 4:21 AM, Dmitry Lomov <dslomov at chromium.org>wrote:
>>
>>> string, boolean, object and any are all lowercase (we should fix the
>>> wiki)
>>>
>>> FWIW, I am already working on a new version of polyfill. It is fully ES5.
>>> Here is a pull request: https://github.com/dherman/structs.js/pull/12 -
>>> I'll merge it soon, and work more to cover everything in the proposal.
>>>
>>> Thanks,
>>> Dmitry
>>>
>>>
>>>
>>> On Wed, Aug 21, 2013 at 3:21 AM, Andrea Giammarchi <
>>> andrea.giammarchi at gmail.com> wrote:
>>>
>>>> sorry, point 3 was actually the question about point 2
>>>>
>>>>
>>>> On Tue, Aug 20, 2013 at 6:20 PM, Andrea Giammarchi <
>>>> andrea.giammarchi at gmail.com> wrote:
>>>>
>>>>> 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)
>>>>>
>>>>> Thanks.
>>>>>
>>>>>
>>>>> On Tue, Aug 20, 2013 at 4:55 PM, Andrea Giammarchi <
>>>>> andrea.giammarchi at gmail.com> wrote:
>>>>>
>>>>>> Awesome, thanks!
>>>>>>
>>>>>>
>>>>>> On Tue, Aug 20, 2013 at 4:12 PM, David Herman <dherman at mozilla.com>wrote:
>>>>>>
>>>>>>> On Aug 20, 2013, at 1:31 PM, Andrea Giammarchi <
>>>>>>> andrea.giammarchi at gmail.com> wrote:
>>>>>>>
>>>>>>> > [In this page](
>>>>>>> http://wiki.ecmascript.org/doku.php?id=harmony:typed_objects), 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:
>>>>>>>
>>>>>>>     https://bugzilla.mozilla.org/show_bug.cgi?id=578700
>>>>>>>
>>>>>>> Dmitriy Lomov is actively working on updating the prollyfill to
>>>>>>> match the current API:
>>>>>>>
>>>>>>>     https://github.com/dherman/structs.js
>>>>>>>     https://github.com/dherman/structs.js/pull/12
>>>>>>>
>>>>>>> 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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>>>>
>>>>
>>>
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>>
>
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