Re: short-tag considered unhealthy
> Date: Wed, 11 Sep 96 16:03:15 CDT
> From: Michael Sperberg-McQueen <U35395@UICVM.CC.UIC.EDU>
> On the other hand -- there are one or two uses of SHORTTAG that I don't
> think complicate parsing all that much, and might be retained:
> - empty end-tags
> - attribute values without quotes around them
I feel strongly that both of these should not be included in XML.
They are not necessary to make XML work. Certainly they are
convenient when entering XML by hand, but according to our design
principles that is not a sufficient justification for including
something in XML.
In my experience what makes SGML hard to implement is not so much
particular features but the huge weight of hundreds of little features
like these, which are all individually fairly easy to implement, but
which collectively make implementing SGML hard and a lot of work. I
think it's vital that we be absolutely fanatical about excluding SGML
features from XML unless they are absolutely essential. We must avoid
the danger of looking at each feature individually and saying "I like
this feature, it's not difficult to implement, so let's leave it in".
> - the omission of attributes which have default values. Without
> SHORTTAG or OMITTAG turned on, 8879 requires that a value be specified
> for every attribute which isn't defaulted to #IMPLIED -- I think it
> would be better to allow omission of attribute value specifications
> for all attributes not #REQUIRED.
I think there's an argument that this is an essential feature. Some
DTDs especially those using architectural forms have a lot of
defaulted attributes on almost every element.
On the other hand it complicates DTD-less processing: for example, it
would make it hard for a browser to display a document correctly
without the DTD.