[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: DTDs, W3C Schemas, RELAX NG, Schematron?

• To: dbox@m... (Don Box)
• Subject: Re: DTDs, W3C Schemas, RELAX NG, Schematron?
• From: John Cowan <jcowan@r...>
• Date: Mon, 24 Jun 2002 08:02:06 -0400 (EDT)
• Cc: jcowan@r... (John Cowan), clbullar@i... ("Bullard, Claude L (Len)"), xml-dev@l...
• In-reply-to: <CFC4F26947496E4092489B2425614958057FA6A0@s...> from "Don Box" at Jun 23, 2002 08:37:14 PM

Don Box scripsit:

> Specifically, XML Schema uses named types to implicitly convey intention
> as well as structure (a la Java, C++, C#). Anonymous types are 2nd class
> citizens in XML Schema (they're type-equivalent with nothing).
> 
> Relax NG has a much looser model (a la Perl) in which two things are
> compatible if they share structure independent of a common, named type
> definition.

Another way to put this, I think, is that while RNG has only one
kind of validation, namely schema-instance validation (the schema
determines what part of the instance is valid), WXS has two more:
instance-instance validation, where parts of the instance must be
mutually valid as specified by the schema (identity constraints, e.g.);
and schema-schema validation, where the rules of WXS determine
whether parts of the schema are mutually valid (e.g. the rules for
substitution groups, which just looks like choice from an RNG viewpoint).

> Each approach appeals to its own community of users in very deep ways.

Evidently.

-- 
John Cowan <jcowan@r...>     http://www.reutershealth.com
I amar prestar aen, han mathon ne nen,    http://www.ccil.org/~cowan
han mathon ne chae, a han noston ne 'wilith.  --Galadriel, _LOTR:FOTR_

• References:
  • RE: DTDs, W3C Schemas, RELAX NG, Schematron?
    • From: "Don Box" <dbox@m...>

• Prev by Date: RE: DTDs, W3C Schemas, RELAX NG, Schematron?
• Next by Date: Re: Suggestions for a slightly less verbose (and easier toauthor) XML
• Previous by thread: Re: DTDs, W3C Schemas, RELAX NG, Schematron?
• Next by thread: Re: DTDs, W3C Schemas, RELAX NG, Schematron?
• Index(es):
  • Date
  • Thread