appendix_a.json is not I-JSON

[hildjj]

appendix_a.json is not terribly interoperable; the big integers lose precision when parsed with ECMAscript's JSON.parse(). RFC 7493 specifies a set of interoperability constraints that would be useful here.

If backward-compatibility is desired, a new property code be added. Example:

  {
    "cbor": "O///////////",
    "hex": "3bffffffffffffffff",
    "roundtrip": true,
    "decoded": -18446744073709551616,
    "decoded2": {
       "type": "bigint",
       "value": "-18446744073709551616"
    }
  },

This still wouldn't be I-JSON compliant, but would allow systems that have the constraints noted there to use this without as many gyrations.

[nelsonxb]

Some parsers (the one I know of at the moment is the one in Nim's standard library) will just reject the whole file thanks to these massive numbers. I plan to submit a PR tonight that makes these tests use "diagnostic" rather than "decoded".