Re: Type and Structure Re: ASN.1 and XML

[Al Snell <alaric@alaric-snell.com>]

On Sun, 27 May 2001, Rick Jelliffe wrote:

> > The point I like to contribute is the subtle
> > difference between type and structure. XML Schema
> > and ASN.1 have the same problem: too strong a type
> > flavor. XML allows a wide spectrum between a simple
> > structural checking to a pseudo-typing system while
> > ASN.1 is a rigid typing system.

That doesn't stop you defining a rigid type that fits *all* (well
formed) XML documents:

Node ::= CHOICE {
	processingInstruction ProcessingInstruction,
	element Element,
	comment UTF8String,
	cdata UTF8String,
	entityRef UTF8String
}

ProcessingInstruction ::= SEQUENCE {
	target UTF8String,
	body UTF8String
}

Element ::= SEQUENCE {
	name UTF8String,
	attributes SEQUENCE OF Attribute,
	children SEQUENCE OF Node
}

Attribute ::= SEQUENCE {
	name UTF8String,
	body SEQUENCE OF CHOICE {
		text UTF8String,
		entityRef UTF8String
	}
}

> > However, I personally do not think ASN.1 as it is
> > can be a real competition for XML, unless XML is
> > completely absorbed into ASN.1.

That's what's being worked on. Fingers crossed!

> Rick Jelliffe

ABS

-- 
                               Alaric B. Snell
 http://www.alaric-snell.com/  http://RFC.net/  http://www.warhead.org.uk/
   Any sufficiently advanced technology can be emulated in software