October 2019 - dfdl-wg - lists.ogf.org

Agenda for OGF DFDL WG Call
by Steve Hanson 16 Oct '19

16 Oct '19

Please find agenda for next call on Redmine at https://redmine.ogf.org/dmsf_files/13597?download= Regards Steve Hanson IBM Hybrid Integration Architect, IBM DFDL Co-Chair, OGF DFDL Working Group smh(a)uk.ibm.com tel:+44-1962-815848 mob:+44-7717-378890

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Tracker 333 - new bitOrder byteOrder combimation - dever to DFDL 2.0 ?
by Mike Beckerle 15 Oct '19

15 Oct '19

See https://redmine.ogf.org/issues/333 This tracker was to add the leastSignificantBitFirst bigEndian combination to the legal values. for bitOrder byteOrder I propose this is deferred to DFDL 2.0. While we have seen one case where this does appear to be used, it is not significant enough to warrant this change in DFDL v1.0. 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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terminology corrections on initiatedContent descriptions
by Mike Beckerle 14 Oct '19

14 Oct '19

Section 14 For property initiatedContent The sentence "If the child is optional then it is deemed to have been found when its initiator has been found." should use consistent terminology of "known to exist" as follows "If the child is optional then it is known to exist when its initiator is found." Section 15 as well, also for initiatedContent "The branch is deemed to have been found when its initiator has been found." replace "The branch is known to exist when its initiator is found." I would categorize these corrections as "minor/typographical". 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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Tracker 340 (Action 301) Experimental Features Conventions
by Mike Beckerle 11 Oct '19

11 Oct '19

I have uploaded a GWD-I document describing these. https://redmine.ogf.org/dmsf_files/13594?download= Please review. 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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recent puzzlers on fn:count and fn:exists
by Mike Beckerle 09 Oct '19

09 Oct '19

These questions came up recently from daffodil users. I know what Daffodil will return here, but the spec is not clear to me as to whether that's the right answer or is even defined. Can an array count itself? Like this: <xs:element name="name" type="xs:string" maxOccurs="unbounded"> <xs:annotation> <xs:appinfo source="http://www.ogf.org/dfdl/"> <dfdl:discriminator test="{ fn:count(.) le 5 }" /> </xs:appinfo> </xs:annotation> </xs:element> The above can be reformulated by calling instead of fn:count, dfdl:occursIndex(), and that's definitely well defined in this case. But what does fn:count return in this case? Daffodil will return the same value as the occursIndex, because it will have speculatively attached the array element to the infoset at the time the fn:count function is being evaluated. But I don't know if that is the right answer or if we should simply say that fn:count is not defined in this case. Similarly, does an array element exist when it is being parsed? <xs:element name="name" type="xs:string" maxOccurs="unbounded"> <xs:annotation> <xs:appinfo source="http://www.ogf.org/dfdl/"> <dfdl:discriminator test="{ fn:exists(.) }" /> </xs:appinfo> </xs:annotation> </xs:element> 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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Problem: simple format that is impossible to model
by Mike Beckerle 03 Oct '19

03 Oct '19

I have a dead-simple little format: data/data/data/data data/data/data/data it is lines of "/" separated strings. All elements are optional. I simply want this: data//data to round trip. For that to happen I need it to parse into <field>data</field><field></field><field>data</field> That is, I require that empty field element in the middle to be created and put into the infoset. I can find no way to do this. The strings have no initiator/terminator, so dfdl:emptyValueDelimiterPolicy is not relevant. All the elements are optional, so default values aren't relevant. The spec states: 9.4.2.2 Simple element (xs:string or xs:hexBinary) Required occurrence: If the element has a default value then an item is added to the infoset using the default value, otherwise an item is added to the Infoset using empty string (type xs:string) or empty hexBinary (type xs:hexBinary) as the value. Optional occurrence: If dfdl:emptyValueDelimiterPolicy is not 'none'[12] <https://daffodil.apache.org/docs/dfdl/#_ftn12> then an item is added to the Infoset using empty string (type xs:string) or empty hexBinary (type xs:hexBinary) as the value, *otherwise nothing is added to the Infoset*. There are errata/actions to clarify wording here around dfdl:emptyValueDelimiterPolicy being in effect or not (because there is no initiator/terminator for it to use as opposed to the property in isolation just being 'none'). But that doesn't change anything about this issue. If this very simple format is not possible, then we need a property or new property enum value that makes it possible. Thoughts? 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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