Re: A really micro schema language

On Wed, Dec 19, 2012 at 1:55 AM, Henry S. Thompson <ht@inf.ed.ac.uk> wrote:

I
> bother to mention it because it uses a closed-world assumption rather
> than requiring explicit negation, which may be a bit more intuitive?
>

I want to allow people to write partial schemas.  It should be possible for
somebody to write as much of a schema as is useful; error handling and
editing should gradually improve in quality as the schema becomes more
complete.  For example, it ought to be possible to say that br and img are
empty. With negation this is easy

  br, img !/ .text, *

Without negation, it's a little less obvious.  One possibility would be to
say something like

  br, img / .empty

where .empty matches neither text nor any element, and the default rule
would be

  .other / *

where .other matches any element not explicitly mentioned on the LHS of a
rule.

I need to spend some time thinking this through.

James