January 2016 - dfdl-wg - lists.ogf.org

still no need for fn:error
by Mike Beckerle 03 Aug '16

03 Aug '16

Here's the example as suggested by Jonathan of how to issue an error that I previously was suggesting needed fn:error. I'm convinced this is sufficient and we can avoid the need for fn:error now. <xs:element name="magic_number" type="ex:uint32" dfdl:byteOrder="bigEndian"> <xs:annotation> <xs:appinfo source="*http://www.ogf.org/dfdl/*<http://www.ogf.org/dfdl/dfdl-1.0/> "> <dfdl:assert test="{ (xs:unsignedInt(.) eq *dfdl:hUInt('0xa1b2c3d4')*) | (xs:unsignedInt(.) eq *dfdl:hUInt('0xd4c3b2a1')*) }" message="{ fn:concat( 'Magic number ', dfdl:hexBinary(dfdl:unsignedInt(.)), ' was not 0xA1B2C3D4 (for bigEndian) or 0xD4C3B2A1 (for littleEndian).' }" /> <dfdl:setVariable ref="ex:bOrd">{ xs:unsignedInt(.) }<dfdl:setVariable> </xs:appinfo> </xs:annotation> </xs:element> -- Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | www.tresys.com

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Re: [DFDL-WG] clarification needed - unparser - do we use mandatory text alignment for zero-length strings?
by Mike Beckerle 22 Jan '16

22 Jan '16

Thanks. I think the simplest way to say this is that the element is aligned because it is representation text and the charset has a mandatory alignment, the element content is of length 0. The alignment of the element and the content length are orthogonal. Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | www.tresys.com Please note: Contributions to the DFDL Workgroup's email discussions are subject to the OGF Intellectual Property Policy <http://www.ogf.org/About/abt_policies.php> On Fri, Jan 22, 2016 at 4:35 AM, Steve Hanson <smh(a)uk.ibm.com> wrote: > Hi Mike > > If we are unparsing an occurrence then yes we apply alignment properties > before we output the content, even if the content is zero length. I > emphasise "if we are unparsing an occurrence" because if an element is > optional and there is no occurrence in the infoset we will not unparse > anything, so the alignment is not relevant and not used. > > Regards > > Steve Hanson > Architect, *IBM DFDL* > <http://www.ibm.com/developerworks/library/se-dfdl/index.html> > Co-Chair, *OGF DFDL Working Group* <http://www.ogf.org/dfdl/> > *IBM Integration Bus* > <http://www-03.ibm.com/software/products/en/ibm-integration-bus>, > Hursley, UK > *smh(a)uk.ibm.com* <smh(a)uk.ibm.com> > tel:+44-1962-815848 > mob:+44-7717-378890 > > > > From: Mike Beckerle <mbeckerle.dfdl(a)gmail.com> > To: "dfdl-wg(a)ogf.org" <dfdl-wg(a)ogf.org> > Date: 21/01/2016 22:37 > Subject: [DFDL-WG] clarification needed - unparser - do we use > mandatory text alignment for zero-length strings? > Sent by: "dfdl-wg" <dfdl-wg-bounces(a)ogf.org> > ------------------------------ > > > > > Suppose field 1 is 3 bits long. > > Suppose field 2 is a string in utf-8. dfdl:emptyValueDelimiterPolicy='none' > > If field2 has any contents, then those characters must begin on a byte > boundary, so before the first character we will skip 5 bits. > > What if field2 is of length 0 ? Do we skip 5 bits anyway or not? > > Note that if dfdl:emptyValueDelimiterPolicy is "both", and an initator or > terminator is defined, then even if length is 0 we definitely will unparse > a character at least so the 5 bits of alignment are needed in that case. > > But if there is no framing, and no content, do we align to the text > mandatory alignment or not? > > Now, I believe the answer to this should be "yes" we skip the 5 bits > anyway. Because if field 2 is lengthKind='pattern', then when parsing, we > have to scan for a match to the pattern, and so we have to know where to > start the scan, which has to be at a byte boundary. So even if there is no > match, so the length at parse time is zero, we still had to skip 5 bits > before we could start scanning. > > So to be consistent with this, I believe unparsing must also output the 5 > bits regardless of whether the string is length 0 or not. > > So there's what should it do, but also if all the constructs for this work > in IBM DFDL, I'm curious what it actually does. > > Thanks > > Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | > *www.tresys.com* <http://www.tresys.com/> > Please note: Contributions to the DFDL Workgroup's email discussions are > subject to the *OGF Intellectual Property Policy* > <http://www.ogf.org/About/abt_policies.php> > -- > dfdl-wg mailing list > dfdl-wg(a)ogf.org > https://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 >

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clarification needed - unparser - do we use mandatory text alignment for zero-length strings?
by Mike Beckerle 22 Jan '16

22 Jan '16

Suppose field 1 is 3 bits long. Suppose field 2 is a string in utf-8. dfdl:emptyValueDelimiterPolicy='none' If field2 has any contents, then those characters must begin on a byte boundary, so before the first character we will skip 5 bits. What if field2 is of length 0 ? Do we skip 5 bits anyway or not? Note that if dfdl:emptyValueDelimiterPolicy is "both", and an initator or terminator is defined, then even if length is 0 we definitely will unparse a character at least so the 5 bits of alignment are needed in that case. But if there is no framing, and no content, do we align to the text mandatory alignment or not? Now, I believe the answer to this should be "yes" we skip the 5 bits anyway. Because if field 2 is lengthKind='pattern', then when parsing, we have to scan for a match to the pattern, and so we have to know where to start the scan, which has to be at a byte boundary. So even if there is no match, so the length at parse time is zero, we still had to skip 5 bits before we could start scanning. So to be consistent with this, I believe unparsing must also output the 5 bits regardless of whether the string is length 0 or not. So there's what should it do, but also if all the constructs for this work in IBM DFDL, I'm curious what it actually does. Thanks Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | www.tresys.com Please note: Contributions to the DFDL Workgroup's email discussions are subject to the OGF Intellectual Property Policy <http://www.ogf.org/About/abt_policies.php>

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OGF DFDL WG Call 2016-01-19 - cancelled
by Steve Hanson 19 Jan '16

19 Jan '16

Steve not available so cancelling. Next meeting is February 2nd. Regards Steve Hanson Architect, IBM DFDL Co-Chair, OGF DFDL Working Group Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848

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Cancelled: OGF DFDL Working Group call
by Steve Hanson 19 Jan '16

19 Jan '16

Steve unable to make the meeting

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OGF DFDL WG Call Minutes 2016-01-05
by Steve Hanson 06 Jan '16

06 Jan '16

Please find minutes from the above call at https://redmine.ogf.org/dmsf_files/13511?download= Regards Steve Hanson Architect, IBM DFDL, Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848

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OGF DFDL WG Call Agenda 2016-01-05
by Steve Hanson 04 Jan '16

04 Jan '16

Please find agenda for call on Redmine at https://redmine.ogf.org/dmsf_files/13511?download= Please note new time 3pm GMT / 10am EST. Regards Steve Hanson Architect, IBM Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848

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