Re: [gentoo-dev] New schema language for metadata validation?

[Dirkjan Ochtman]

On Wed, Jan 27, 2016 at 4:20 PM, Michał Górny <mgorny@g.o> wrote:
> First of all, I don't like RELAX-NG Compact at all. It looks like
> someone tried hard to combine some variation of BNF, DOCTYPE
> and something else in order to get something that is both readable
> and compact. And got a result that doesn't meet either criteria.
> It looks like some terrible mixture of over-verbose descriptive text
> format with a lot of enigmatic symbols that are not even clear what
> they apply to.

Wow, that's surprising to me! I found that a lot of the compact syntax
made immediate sense to me as I was already familiar with what ?*+
mean from EBNF and regular expressions. For me, it's mostly how much
less verbose it is than a full XML syntax that makes it easier to
comprehend and manipulate.

> Secondly, RELAX-NG and XML Schema look pretty similar in volume.
> However, XML Schema looks definitely more readable, robust and XML-ish
> (and doesn't use camelcase!). Furthermore, as far as I'm aware XML
> Schema is more widely supported (not sure if that applies to any tools
> we're considering).

I agree that XML Schema is probably more widely supported, though it'd
be hard to assess by how much. On other hand, I find XML Schema much
less readable; and it feels like "more XML-ish" is just because it
uses namespaces a lot more, and is more commonly used? Indeed, to me
the fact that RELAX NG is less XML-ish is a positive aspect.

> Therefore, I'd suggest we just ship properly hand-written XML Schema,
> with some nice comments. I don't see a reason to ship any RELAX-NG
> files unless we actually have tools that support only that.

I'd be curious what Michael, Ulrich, and others think.

Cheers,

Dirkjan