RE: Accelerated CAP (draft-2)

[Chris Newman <Chris.Newman@xxxxxxxxxxxx>]

On Wed, 16 Sep 1998, Lisa Lippert (Dusseault) (Exchange) wrote:
>  - XML parsers are simple.  

Trivially true because parsers are simple for almost any regular data
format.

However, XML interpretors could be extremely complex, especially if they
support things like arbitrary PITargets and automated DTD discovery.

>  - XML parsers are becoming ubiquitous -- i.e. shipping in IE

If there was an XML parsing API in every major OS, then it would be
ubiquitous.  Hype for XML may be ubiquitous, but just because it's
shipping in one Microsoft product does not mean it's ubiquitous.  In
addition, regular expressions are ubiquitous, but that doesn't mean we
should use them everywhere.

>  - XML will become the preferred structured data format for many clients,
> including many MS clients.

Predicting the future.

>  - XML works well on light-weight devices, on which users will certainly
> want to have their calendar.

Are you sure?  Is there a sample palm pilot client supporting the full
generality of XML including DTD interpretation and discovery?  And will 
the 7 or 8 ways of encoding the same character in XML work reliably?

>  - XML can convert fairly easily to and from legacy formats.  Either the
> server or the client can do the conversion, but a good server for thin
> clients would do conversion to XML so that the thin client only needs one
> parser.

Just because conversion is easy, doesn't mean it should be done.  It's
easy to convert stored Internet mail to using LF-separated lines, but it
breaks all sorts of things.

> The big thing I don't want to do is perpetuate non-XML formats by defining
> new ones.

I'll tentatively and conditionally agree with this one.  An XML-structured
syntax is far from the worst choice one could make and in the grand scheme
of things, syntax matters little for new work.  But iCalendar is a done
deal.

> That just increases the eventual pain of switching.

Switching to XML from an existing format is more likely to be a bad thing
than a good thing, IMHO.  Parsers are simple, re-deploying code and
creating migration infrastructures is very hard.  Switching to XML might
save a few screenfuls of code if the migration ever completes, but during
the process of the migration there will need to be hundreds of pages of
transition code.  It usually won't be worth it.

		- Chris