[DFDL-WG] DFDL: Minutes from OGF WG call, 05 Octobet 2008
Alan Powell
alan_powell at uk.ibm.com
Thu Nov 6 10:54:43 CST 2008
Open Grid Forum: Data Format Description Language Working Group
Weekly Working Group Conference Call
13:00 GMT, 5 November 2008
Attendees
Steve Hanson (IBM)
Mike Beckerle(Oco)
Alan Powell (IBM)
1. End Of Parent
Discussed last proposal and subsequent emails.
Decided:
Only last element in a sequence can have lenghtkind=EndOfParent
Sequence can also have lengthKind=EndOfParent - means take length from
parent sequence.
LengthKind=endOfParent on outermost sequence means end of data stream. So
for the last field in a definition to extend to the end of the data stream
the element has lengthKind="endOfParent" and the enclosing sequence, and
all parent sequences including outermost also have
lengthKind="endOfParent"
Examples
1. Last element to end of data stream
<xsd:sequence>
<xsd:annotation>
<xsd:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:format lengthKind="endOfParent" />
</xsd:appinfo>
</xsd:annotation>
<xs:element name="mandt" type="xsd:string"/>
<xsd:annotation>
<xsd:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:format lengthKind="explicit" length="3"/>
</xsd:appinfo>
</xsd:annotation>
</xsd:element>
....
<xs:element name="last" type="xsd:string"/>
<xsd:annotation>
<xsd:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:format lengthKind="endOfParent"/>
</xsd:appinfo>
</xsd:annotation>
</xsd:element>
</xsd:sequence>
2. last element to fixed length container
<xsd:sequence>
<xsd:annotation>
<xsd:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:format lengthKind="explicit" length="100" />
</xsd:appinfo>
</xsd:annotation>
<xs:element name="mandt" type="xsd:string"/>
<xsd:annotation>
<xsd:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:format lengthKind="explicit" length="3"/>
</xsd:appinfo>
</xsd:annotation>
</xsd:element>
....
<xs:element name="last" type="xsd:string"/>
<xsd:annotation>
<xsd:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:format lengthKind="endOfParent"/>
</xsd:appinfo>
</xsd:annotation>
</xsd:element>
</xsd:sequence>
3. last element to container terminator
<xsd:sequence>
<xsd:annotation>
<xsd:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:format lengthKind="delimited" terminator="$" />
</xsd:appinfo>
</xsd:annotation>
<xs:element name="mandt" type="xsd:string"/>
<xsd:annotation>
<xsd:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:format lengthKind="explicit" length="3"/>
</xsd:appinfo>
</xsd:annotation>
</xsd:element>
....
<xs:element name="last" type="xsd:string"/>
<xsd:annotation>
<xsd:appinfo source="http://www.ogf.org/dfdl/">
<dfdl:format lengthKind="endOfParent"/>
</xsd:appinfo>
</xsd:annotation>
</xsd:element>
</xsd:sequence>
Isn't this the same as "last " with lengthKind = "delimited"?
2. Selectors
Discussed Suman's suggestion from last weeks call.
- If a selector is supplied, then only dfdl:format blocks matching that
selector are used
- If a selector is not supplied, then only dfdl:format blocks without a
selector are used
Decided this is too restrictive as it requires a format block for each
selector on every item even if they define the same properties so stayed
with previous decision
- If selector is supplied and matches one of the dfdl:format blocks then
that block is used.
- Otherwise the dfdl:format block with no selector is used.
Reiterated that selectors are qnames.
3. Moving to XSD 1.1 as base for DFDL
Benfits:
Can use xsd:all instead of introducing unordered sequences.
weakened wildcard rules.
Agreed in principle. MB to investigate to look at the other changes in
Schema 1.1 to check effect on other dfdl functions and restrictions
4. Not dicussed
SCD spec changes
Multi-level semntics
2. AOB
Next call 12 November
Meeting closed, 13:10 GMT
Actions raised at this meeting
No
Action
023
MB: Review Schema 1.1
Current Actions:
No
Action
003
AP: Update spec from WTX document
13/8: All resolved issues have been added to spec. Remaining unresolved
items need discussion
10/9: Alan will pull out the remaining unresolved items and circulate for
discussion next week
17/9: Doc distributed and partially discussed
15/10: All updateds complete except minlength
22/10: No update
004
MB: Mike will also author a new section in response to comments from Sandy
Gao and Suman Kalia, explicitly connecting syntax with DFDL semantics
16/7: no progress
10/9: Mike not convinced this is necessary. Steve to talk to Sandy to see
if it is needed for any IBM implementation that extends the existing XML
parsing framework
15/10: SH to talk to Sandy
22/10: SH needs reminding of what this issue is about
007
AP: enum + expression wording
13/8: no progress
10/9: No update
17/9: No update
22/10: No update
012
AP/SH: Update decimalCalendarScheme
10/9: Not allocated yet
17/9: No update
24/9: Add calendar binary formats to actions
22/10: No progress
014
SH: Use cases for lengthKind pattern on binary fields.
10/9: Not done
17/9: No update
22/10: SH not sure he can provide a concrete use case
016
AP: Add hidden changes to spec
22/10: No update
017
All: Review EndOfData changes
22/10: SH response mailed to Mike
018
AP: Agree padding to minimum length
15/10: Needs documenting
22/10: No update
019
AP: Document defineTextNumber etc
22/10: No update
020
SH: Resolve packedDecimalSignCodes behaviour depends on NumberCheckPolicy
22/10: No progress
021
AP: Document textNumberRepresenation and binaryNumberRepresentation
22/10: No update
022
SH: Talk to Sandy Gao to assess use of schema 1.1
22/10: Mail sent to Sandy
Closed actions:
033 Work items:
No
Item
001
String XML type (Ian P) - Apr 30, 2008
002
Escape schemes (Ian P) - Apr 30, 2008
003
Variables - ??, 2008 (Mike)
004
Selectors (Suman/Alan) - Apr 30, 2008
005
Improvements on property descriptions - ??, 2008 (All - split TBD)
006
Envelopes and Payloads (Steve) - Apr 30, 2008
007
(from draft 32) valueCalc (Mike) - ??, 2008 *Mostly complete*
008
(from draft 32) Property precedence for writing (Steve) - *complete but
under review*
009
(from draft 32) Variable markup (Steve) - Mar 31, 2008 *proposal needs
writing up*
010
(from draft 32) Assertions, discriminators and choice, including
discussion of timing option (Suman) - Mar 31, 2008 * in progress *
011
(from draft 32) How speculative parsing works (combining choice and
variable-occurence - currently these are separate) ??, 2008 (IBM) * in
progress *
012
(from draft 32) Reordering the properties discussion: move representation
earlier, improve flow of topics ??, 2008 (Alan) * not started *
013
(from F2F) New scoping rules
014
(from F2F) Occurs, OccurSeparator changes
015
(from F2F) choices and Output (Mike)
016
(from F2F) xpath forward references (Alan) *complete*
017
(IBM WTX review) Minor agreed updates (Alan) *complete*
018
(IBM WTX review) Review generateNewLine (Alan) *complete*
020
(IBM WTX review) Special value for zero seen eg 'zero'. (Steve)
021
(IBM WTX review) 'EndOfData' changes (Alan)
022
(IBM WTX review) Unresolvable choices - infoset changes *complete*
023
(IBM WTX review) separatorKind=?prefix? ?infix? or ?postfix? (Alan)
024
(IBM WTX review) StopValue clarification (Alan)
025
Augmented infoset and unparsing (Alan)
026
Hidden changes
027
Add decimal supp to main spec
028
Remove extended floats
Alan Powell
MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England
Notes Id: Alan Powell/UK/IBM email: alan_powell at uk.ibm.com
Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898
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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