Re: [Json] JSON Schema Language

[Carsten Bormann <[e-mail]>]

On May 6, 2019, at 09:22, Austin Wright <[e-mail]> wrote:
> 
> But also, why not build a parser that uses a schema to influence how values are parsed?

That is exactly what most of the members of this WG are afraid of when the talk comes to “schemas”.

XML (and later JSON) learned one thing from the problems of SGML: schema-oblivious decoders are more robust than schema-depending ones.
(They are, in the first place, and protocol evolution only amplifies this.)

> Suppose you have a dynamically typed language, and want to parse some value, e.g. sometimes as an int, sometimes as a bignum, depending on the property. You might provide a JSON Schema to specify this behavior.

There goes the generic decoder.

(There is nothing wrong with using a “schema” to specify upconversion from the JSON data model to your application data model.  What I’m objecting to is getting rid of JSON and replacing it with a gazillion dialects that happen to be syntactically compatible with JSON but the semantics of which are controlled by a “schema” mechanism.)

Grüße, Carsten