Hmm. We're in this situation where DFDL is so rich with features that anything those features don't handle will by definition be an obscure corner case thereby hard to motivate. I can change this example to use three single byte binary integers instead of 6 packed decimal digits. This is certainly a feasible binary data format, though it's nothing I've ever seen. It also makes the example orthogonal to the decimal changes, so generally is more on point. Attachment is new example plus the other improvements suggested. _____ From: Steve Hanson [mailto:smh@uk.ibm.com] Sent: Wednesday, April 09, 2008 9:29 AM To: mbeckerle.dfdl@gmail.com Cc: dfdl-wg@ogf.org Subject: Re: [DFDL-WG] DFDL: Calculated Values section rewrite Comments from Ian and Steve: 1) Is it a schema error if default/fixed attributes specified along with dfdl:inputValueCalc and/or dfdl:outputValueCalc? 2) 2D array. - dfdl:occurrences() is not in the expression language in draft 031. Is something missing from the language, or should the XPath count() function be used here? - $dfdl:occurrences - $ not needed - dfdl:outputValueCalc for 'ncols' - we think the else clause should be '..\rows[1]\cols' 3) PD date - As an example, it's perhaps not a good one as we have decimalCalendarFormat as a property of a decimal number, which is intended to do exactly this - As it stands, it will need updating to reflect latest decimal supplement Regards, Steve Steve Hanson Programming Model Architect WebSphere Message Brokers Hursley, UK Internet: smh@uk.ibm.com Phone (+44)/(0) 1962-815848 "Mike Beckerle" <mbeckerle.dfdl@gmail.com> Sent by: dfdl-wg-bounces@ogf.org 09/04/2008 02:44 Please respond to mbeckerle.dfdl@gmail.com To Alan Powell/UK/IBM@IBMGB cc dfdl-wg@ogf.org, dfdl-wg-bounces@ogf.org Subject Re: [DFDL-WG] DFDL: Calculated Values section rewrite I've attached a revised calculated value properties doc which incorporates suggestions from Alan, specifically, there's a new example, which is a 2-d array with nrows, ncols fields stored before it. I think this motivates the connection between outputValueCalc, and number of occurrences and occurs calculations nicely. .mikeb _____ From: Alan Powell [mailto:alan_powell@uk.ibm.com] Sent: Thursday, March 27, 2008 2:02 PM To: mbeckerle.dfdl@gmail.com Cc: dfdl-wg@ogf.org; dfdl-wg-bounces@ogf.org Subject: Re: [DFDL-WG] DFDL: Calculated Values section rewrite Mike A couple of comments on the using derived/representation nomenclature with OutputValueCalc and a couple of minor corrections. However I thought the Length Prefix example a bit odd as I would have expected a single HexBinary element rather than an array of bytes. Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell@uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 From: "Mike Beckerle" <mbeckerle.dfdl@gmail.com> To: <dfdl-wg@ogf.org> Date: 26/03/2008 16:39 Subject: [DFDL-WG] DFDL: Calculated Values section rewrite _____ My deliverable for the next draft (32) was to revise the calculated values section. I have rewritten it and the draft is attached. Of note: I have removed the troublesome "outputLengthCalc" property, as I no longer see a critical need for it. One of the examples computes the number of occurrences for a byte array, and I think that mechanism along with alignment is sufficient to handle the troublesome cases I was considering where size of padding had to be dynamically computed. The section now consists of a short table of definition, followed by illustrative examples, however, I think this is fine. The semantics of inputValueCalc and outputValueCalc aren't really that complex. They can be described in a paragraph. It is the motivation for them that is complicated, so I think examples in the spec, while sometimes considered problematic, are OK in this case. [attachment "calculated-value-properties.doc" deleted by Alan Powell/UK/IBM] -- dfdl-wg mailing list dfdl-wg@ogf.org <http://www.ogf.org/mailman/listinfo/dfdl-wg> http://www.ogf.org/mailman/listinfo/dfdl-wg _____ Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU -- dfdl-wg mailing list dfdl-wg@ogf.org http://www.ogf.org/mailman/listinfo/dfdl-wg _____ Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU