Update exclusive* keywords specification

[dud225]

Hello

Since last year, exclusiveMinimum and exclusiveMaximum are no longer boolean values changing the behaviour of respectively the minimum and maximum keywords, but are now fully independent keywords incompatible with minimum and maximum.

This PR updates the numeric page describing them.

Regards

[handrews]

This is definitely correct for draft-06 and later, but is there any mention of drafts newer than draft-04 in the book yet? As much as I wish it were otherwise, draft-04 is still in wide use so while it's best to encourage newer drafts there should be some acknowledgement somewhere that there are multiple drafts in use and the reader needs to figure out which they want / have available. There's also the change from id -> $id to account for.

I'd be happy to make a PR adding some sort of intro paragraph somewhere if that is of interest.

[mnpenner]

I messed up my JSON Schema validator because of this 😢 PhpStorm just told me my JSON Schema was wrong and that exclusiveMinimum should be a number. I thought PhpStorm was just being crazy again, but it is indeed a number both here and here.

But yeah... I see the problem. If the documentation refers to draft 4 then it should be true for draft 4. I think either the documentation needs to be versioned (hard) or there should just be a little asterisk in the documentation that says "this changed in draft 6" yada yada. Or do the opposite and update the docs for v6 (or 7 I guess we're on now) and add an asterisk for v4.

[handrews]

Unfortunately the future of this resource seems to be in doubt- see #68

Over at the JSON Schema spec project, we don't have enough people to take this on or create a new version. At some point, we'll probably want to remove or at least de-emphasize the link for exactly this sort of problem. There's a real need for an updated book from someone, though.

[mdboom]

Just to address the last comment (which I already mentioned on the JSON Schema Slack): I've been away from this for a while, but probably have some cycles now to get things updated to more recent drafts. I'll merge this into my personal fork until such time as we get the canonical repo moved over to the json-schema org.

[mdboom]

This has been rolled up as part of #74, and should close automatically when that lands.

[cognifloyd]

This should be closed.