Re: [Json] JSON Schema Language

[Carsten Bormann <[e-mail]>]

On May 4, 2019, at 06:47, Anders Rundgren <[e-mail]> wrote:
> 
> Example: although 10.0 is a valid JSON Number, in system where you expect
> an integer, this should be flagged as a syntax error.

10.0 is an integer number.

“Schema Languages” operate at the data model level.  In the JSON data model, there is only one kind of number.  
Of course, the JSON data model is not actually defined in a standard, which is one of the major shortcomings of JSON.

See appendix E of draft-ietf-cbor-cddl-08.txt for the way that is handled in CDDL.

In an alternate JSON universe(*), you would start by applying ISO 6093 (ECMA-63 [1]).
NR1 becomes an integer, NR2 and NR3 become floating point values.  
You then still have to decide what the JSON constructions not covered by ISO 6093 become, e.g., what 1e5 is; in C that would be a float while in Ada that is an integer, IIRC.
If you define that int/float distinction properly, and make it available at the data model level, you can have the “schema language” act on that.

Grüße, Carsten

(*) which is indeed well-supported by implementations outside JavaScript, just not by specifications.
[1] https://www.ecma-international.org/publications/files/ECMA-ST-WITHDRAWN/ECMA-63,%201st%20Edition,%20September%201980.pdf