- From: Eve L. Maler <elm@arbortext.com>
- Date: Wed, 18 Jun 1997 10:34:53 -0400
- To: w3c-sgml-wg@w3.org
As usual, in catching up with a pile of WG mail, I came across one old message that I wanted to respond to. I believe my point has been made implicitly in further responses in this thread, but I thought it was worth making explicitly: At 04:08 PM 6/10/97 -0700, Andrew Layman wrote: >I indeed think of types as equivalent to notations, as your mail points >out. Looking at notations, we see that they identify the format of an >external binary entity, and associate that format with a public >identifier. That is, notations do specify data types, and within the >limits of XML public identifiers, notations are universally unique. > >Notations suffer from a few problems from our point of view, and that is >that they apply only to external entities, and types useful for routine >data processing as types such as INTEGER or DATE are not standardized. >The concepts are very similar, and maybe we can extend the idea of >notation to cover element contents. Notations do not apply only to external entities. In 8879, a NOTATION attribute on an element is meant to convey the notation in which the element content is expressed. XML has retained NOTATION attributes. >However, notations are not the same as namespaces. Namespaces are not >data types. Namespaces are a general mechanism that allows any element >name (or by extension, any name) to be associated with a particular kind >of system literal, a URI, and thereby namespaces allow any name to be >made universally unique. Notations contain a mechanism by which >notations can be universally disambiguated; but it only works for >notations, it isn't general. Namespaces is a general mechanism that >universally disambiguates any name. > >--Andrew Layman > AndrewL@microsoft.com If notation declarations are used to declare namespace ID prefixes, then they do indeed universally disambiguate namespaces. Of course, namespaceID:gi is a novel way of *using* notation names. Eve
Received on Wednesday, 18 June 1997 11:23:13 UTC