[relaxng-user] "Converting DTDs (and DTD developers) to RELAX NG schemas" paper

[DuCharme, Bob (LNG-CHO)]

James,

Thanks very much for the review. (And thanks to everyone else who looked it
over.)

>1. You suggest doing RNG validation in addition to DTD validation. So
>long as you do RNG DTD-compatibility checking, RNG validation alone is
>enough (although I can well imaging non-technical reasons for doing DTD
>validation).

Thanks, good point. I was thinking about the continued use of the DTD as
before, which usually means in conjunction with some app that uses DTDs for
validation and more, such as an editor. I will make this clearer.

>2. With DTD validation, you can only check that the document is valid
>with respect to the DTD that the document specifies.  In many cases,
>even in a DTD-based environment, there is a requirement that the
>document use a specific DTD, but DTD validation provides no way to
>enforce this.  RNG validation helps with this too.

I'm not sure what you mean here--I thought part of the RNG philosophy was to
avoid hard-coding a link between a document and a schema. Can you give me an
example? 

>3. Apropos using these techniques with W3C XML Schema, if you use Trang
>to convert from DTD to XSD, then your parameter entities will be
>preserved, at least to some degree.

I see now that when converting the first example in my article, it does
declare and reference a name.content type, but not a quantity.type one. 

>(What Trang does approximately is
>to expand the parameter entities, keeping track of which parameter
>entities each character in the result comes from, then parse, then
>unexpand those parameter entities that correspond consistently to some
>syntactic unit.)

Well, we certainly have to thank you for going to the trouble, when
according to my research no one else really has!

Bob