Re: Last word on LINKTYPE (hum, hum!)

At 11:24 7/3/97 +0100, Steve Pepper wrote:

>Martin! I thought you knew me better than to think I would propose an
>application specific extension to SGML!

I do - I am aware that you have not thought out all the implications of the
change you suggest:-)

>My thought was that it might serve to enhance the LINK feature generally
>if the syntax allowed some defaulting. Specifically (and this is off the
>top of my head, so please make allowance for that):

>   <!PROCSPEC xml-proc [
>   <!ATTLIST  xref
>              xml-link CDATA #fixed "xml-tlink">
>   ]>
>   <!PROCSPEC xml-proc tei.2 #IMPLIED [                [8879:1986]
>   <!PROCSPEC xml-proc [                               [amended]
>   - defaults to the active document type and implicit link

You need to specifically state what DTD the link was designed for so that
the parser can check that the LPD is not being applied to an DTD it was not
designed to work with

You need to say #IMPLIED so that the parser can check that the option to
allow implied links has been allowed for in the SGML declaration

>   <!PROCDEF #INITIAL xref>                            [8879:1986]

The #INIITIAL makes the fact that this is the start point clear - you gain
nothing by changing it to a default name such as xml-proc

What the xref is meant to show is a puzzle - you have to assign attribute
values to specific element names in the link spec.

>   (omitted)                                           [amended]
>   - default (when no named #INITIAL link set) is that the implied
>     initial link set consists of link rules which use the default
>     values of all attributes declared in the LPD.

Yuk. This will just not work in the case of all SGML LPDs. How are we to
distinguish when it is relevant from the majority of cases where it is not?

>Is there any reason why this wouldn't work and couldn't be useful?
>(Maybe best to answer i private email.)

It may be useful for XML - it is less than useful as a general contraction
of all SGML applications of LPDs. If it cannot be a general change to SGML
XML is no longer SGML conformant, which is what we have all been fighting
for so hard.
Martin Bryan, The SGML Centre, Churchdown, Glos. GL3 2PU, UK 
Phone/Fax: +44 1452 714029   WWW home page: http://www.sgml.u-net.com/