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Re: [Json] "best practices" Vs. Profile for i-json

Phillip Hallam-Baker <ietf@hallambaker.com> Sat, 02 August 2014 14:58 UTC

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From: Phillip Hallam-Baker <ietf@hallambaker.com>
To: John Cowan <cowan@mercury.ccil.org>
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Cc: IETF JSON WG <json@ietf.org>, Larry Masinter <masinter@adobe.com>
Subject: Re: [Json] "best practices" Vs. Profile for i-json
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On Sat, Aug 2, 2014 at 2:11 AM, John Cowan <cowan@mercury.ccil.org> wrote:
> Phillip Hallam-Baker scripsit:
>
>> Not happening unless we move to a binary encoding or a binary exponent
>> encoding. To round trip the floating point between binary and decimal
>> exponents is ridiculously non-trivial.
>
> I don't say it's trivial, but it *is* a solved problem, if by "round
> trip" you mean "guarantee that what one implementation writes, another
> implementation reads as the same float."  The current C and C++
> standards require round-trippability in this sense.

Its not a problem that can be solved in an IETF spec by referencing
another spec.

At the very minimum, code is required. But if it is going to be any
use in practice we would need to validate each implementation which is
hard and there will be many non-compliant implementations around and
no way to know which is which.

IF this is a requirement then extending the spec to include a direct
representation of binary exponent floating point is the only way to be
sure it can be relied on.

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