- From: Eve L. Maler <elm@arbortext.com>
- Date: Thu, 19 Jun 1997 08:30:37 -0400
- To: w3c-sgml-wg@w3.org
- Cc: elm@arbortext.com
The ERB, in its meeting yesterday, discussed the issue of parameter entities in XML. We are *strongly* leaning towards voting to remove parameter entities entirely *from V1.0* as long as GI name groups are reinstated in ELEMENT and ATTLIST declarations: <!ELEMENT (a|b|c) ...> <!ATTLIST (x|y|z) ...> We plan to vote on this at next Wednesday's meeting; your input is welcome. The reasons to prefer GI name groups: o Many of the uses of parameter entities that new DTD writers and simple DTDs are likely to want can be replaced by GI name groups: synchronizing the content models or attribute lists of elements o GI name groups add extremely little complexity to XML processors o Now that we have multiple ATTLISTs, GI name groups have quite a bit more power than they used to (e.g., you can add a set of attributes to "all the list elements," and then add a unique attribute to only one of the elements) o GI name groups give us the syntax (if not the semantics) to do a kind of element subclassing, where all the elements in a "class" have the same characteristics One consequence: o Existing DTDs and any new complex DTDs that need parameter entities would have to be transformed to resolve parameter entities before XML delivery (note that several existing tools, such as NormDTD, do this) Eve
Received on Thursday, 19 June 1997 08:28:06 UTC