Re: [netmod] JSON to XML lossy conversion

[Juergen Schoenwaelder <[e-mail]>]

On Fri, Jul 17, 2020 at 02:12:06PM +0200, Ladislav Lhotka wrote:
> 
> 
> On 17. 07. 20 12:03, Vladimir Vassilev wrote:
> > On 17/07/2020 09.11, Ladislav Lhotka wrote:
> > 
> >>
> >> On 17. 07. 20 8:57, Michal Vaško wrote:
> >>> Hi Carsten,
> >>> you had an interesting idea to have tools that could warn about these
> >>> problems (although that is hardly a proper solution) but it is not
> >>> really possible because the problem may occur whenever there is union
> >>> with a 'string' and 'int8' - 'int32', 'uint8' - 'uint32', or
> >>> 'boolean', in any order. Meaning in lots of, if not most, unions. And
> >>> I have considered only XML and JSON, I have not looked into CBOR,
> >>> which may make it even worse.
> >> What you can do is to define a metadata annotation specifying the union
> >> member for a particular instance, and implement it in your tools. This
> >> would be a solution independent of instance representation.
> > 
> > 
> > IMO this does not solve the problem that XML can not encode all values
> > of the value space in certain awkward unions (JSON and CBOR can't do
> > that either only the constraints are alternative supersets).
> 
> Why not? In XML, everything is encoded as text, and the annotation tells
> how to parse it and interpret. So either the text representation
> conforms to that precise type or otherwise it is an error. There is no
> ambiguity.
>

An annotation that is only understood by some tools and not by others
is creating a new problem since different tools now start to interpret
data in different ways, i.e., the annotation harms interoperability.

/js

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: [phone]         Campus Ring 1 | 28759 Bremen | Germany
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