undefined | Better HN

0 pointskemayo8y ago0 comments

That's per the spec[1], enjoyably:

    Note that when such software is used, numbers that are
    integers and are in the range [-(2**53)+1, (2**53)-1]
    are interoperable in the sense that implementations will
    agree exactly on their numeric values.

2^53 is only 9007199254740990, so it's not too hard to exceed that, particularly in things like twitter status ids.

The recommended use is to have big numbers as strings, since it's the only way to reliably pass them around. (Yes, this is kind of horrible.)

[1]: https://tools.ietf.org/html/rfc7159#section-6

0 comments

falcolas8y ago

I have to admit, I was not familiar with this limitation. Thanks for pointing it out.

And I'd go from "kind of horrible" to just "horrible".

Integral bit limits are an implementation detail that every language has a way to overcome - they shouldn't be built into an encoding spec.

kemayoOP8y ago

Again, not saying this is a good thing, but it's an understandable consequence of the standardization partially involving "let's document how the browsers existing JS implementations deal with running eval on a string". It's easier to write the standard so that existing implementations fit it, rather than requiring changes from everyone.

falcolas8y ago

I imagine it depends on your aims. If your aim is just to document existing behavior, that's one thing. But if your aim is to create a new, simple, data interchange format, documenting existing implementations is only going to limit its usefulness. It could have forced the current implementations fixed instead of setting the bar.

As pointed out upstream, we're dealing with a lot of data these days, and such limitations will only cause JSON to become marginalized or complicated with implementation-dependent workarounds, like integers in strings.

1 more reply

j / k navigate · click thread line to collapse

0 pointskemayo8y ago0 comments

That's per the spec[1], enjoyably:

    Note that when such software is used, numbers that are
    integers and are in the range [-(2**53)+1, (2**53)-1]
    are interoperable in the sense that implementations will
    agree exactly on their numeric values.

2^53 is only 9007199254740990, so it's not too hard to exceed that, particularly in things like twitter status ids.

The recommended use is to have big numbers as strings, since it's the only way to reliably pass them around. (Yes, this is kind of horrible.)

[1]: https://tools.ietf.org/html/rfc7159#section-6

0 comments

falcolas8y ago

I have to admit, I was not familiar with this limitation. Thanks for pointing it out.

And I'd go from "kind of horrible" to just "horrible".

Integral bit limits are an implementation detail that every language has a way to overcome - they shouldn't be built into an encoding spec.

kemayoOP8y ago

falcolas8y ago

1 more reply

j / k navigate · click thread line to collapse