[FWD]Re: Datatype section

[Betty Harvey <ebxml@eccnet.eccnet.com>]

From miller@joaquin.net Mon Jan  8 08:38:36 2001
Date: Mon, 08 Jan 2001 07:33:03 -0800
From: Joaquin Miller <miller@joaquin.net>
Reply-To: Joaquin Miller <joaquin@acm.org>
To: Betty Harvey <harvey@eccnet.com>
Subject: Re: Datatype section

[Betty, will you forward this to ebxml-core@lists.ebxml.org, please?  I
have not been able to send to that list, nor to get a response to my
inquiry as to why.  Thanks.]
 

Philip Goatly wrote:

      ...    I agree Betty has done an excellent job in surfacing
      all these data
      types.

          BUT surely we must remember that any XML message only
      contains text
      data either say ASCII or UNICODE etc. depending on the XML
      'ISO' settings. ...



Phil is right to commend Betty. Good work. And he goes on to make a very
important point. 

Perhaps the decision has already been made, either formally, or by
unspoken consensus, that ebXML needs to define these datatypes, even
knowing that they will be transmitted as text.  (I'm a recent lurker;
that's why i don't know.)

If not, then that needs to be discussed.

If so, then we clearly need to specify at least the text format for each
type.  And we need to discuss whether it is also necessary to specify
conversions to other representations. (Which other representations?)  
Probably everyone knows that already.  Maybe you all agree on the answer.

Here are a few items that are a bit deeper than text format and
conversions.  Since the list comes from a draft standard submitted to
ISO, perhaps this is not the place to mention these items.  If it is not,
please delete this message now.

The list starts of innocently.  String and boolean {true, false}, are
easy to let slip by.  Float and double are well defined by IEEE.  Decimal
can slip by, too (we imagine one through nine with one period in there
somewhere). 

But timeDuration opens up the dread box.  And there are some real
troublemakers in there.  Examples of minor ones are Integer, which
mentions 'scale' and a couple of xIntegers, which mention the even more
obscure 'maxInclusive.'  Those are probably defined somewhere.

timeInstant opens up another box found in the first.  I don't want to go
all philosophical on you, but what is an instant?  might we not want to
have a more realistic idea of time?  There is a whole body of work on
this topic, and it is vital to get this right for distributed systems. 
(I feel that the only realistic model is based on intervals, not
instants, but that is only my opinion.)

The concept, 'midnight,' is famously treacherous.  It's use here seems
ok, but is right at the edge of the cliff.  And it is a cliff, not just a
slippery slope.  There is a rock solid reason lawyers never use the term,
nor the time. 

Wait a minute!  I just read Date again.  Classic case of midnight
trouble.  Of course you all know what is meant, but how about an
arbitrarily selected computer program?

recurringDay and her sister, recurringDate, will be interesting.

And you will all join me in enjoying century.  Happy New Century!  Or am
i late on that?



Cordially,

Joaquin

................................................
Joaquin Miller
Chief Architect
Financial Systems Architects

mailto:joaquin@acm.org

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