Mark
Yes, that makes more sense. The existing wording says:
dfdl:occursIndex()
Returns the position of the current item within an array as an xs:long.
The first element is at position 1.
The function may be used on non-array elements.
So I blindly used xs:long for the argument type as well. On consideration
the argument type should be xs:nonNegativeInteger and so should the return
type.
Could be xs:positiveInteger, but as you say it's not used anywhere in the
spec (no XPath constructor, etc).
Regards
Steve Hanson
Architect, IBM DFDL
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh@uk.ibm.com
tel:+44-1962-815848
From: Mark Frost/UK/IBM
To: Steve Hanson/UK/IBM@IBMGB,
Cc: Mike Beckerle , "dfdl-wg@ogf.org"
, dfdl-wg-bounces@ogf.org
Date: 03/09/2014 13:35
Subject: Re: [DFDL-WG] Action 269: clarification on
dfdl:occursIndex() function
Would a parameter type xs:positiveInteger (right value space) or
xs:NonNegativeInteger (less wrong value space, and already used in DFDL)
be more appropriate?
Regards,
Mark
Mark Frost
IBM United Kingdom
Software Engineer
Hursley Park
IBM DFDL, IBM Integration Bus
Winchester
SO21 2JN
Phone:
+44 (0)1962 817009
England
e-mail:
frostmar@uk.ibm.com
From: Steve Hanson/UK/IBM@IBMGB
To: Mike Beckerle
Cc: "dfdl-wg@ogf.org" , dfdl-wg-bounces@ogf.org
Date: 03/09/2014 13:16
Subject: Re: [DFDL-WG] Action 269: clarification on
dfdl:occursIndex() function
Sent by: dfdl-wg-bounces@ogf.org
Closed. After discussion, settled on an xs:long argument being a 1 based
count up the parent axis. It is a processing error if the argument reaches
beyond the root. It is a schema definition error if the argument is <= 0.
Erratum 2.167 created. To be included in draft r23.
Regards
Steve Hanson
Architect, IBM DFDL
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh@uk.ibm.com
tel:+44-1962-815848
From: Mike Beckerle
To: "dfdl-wg@ogf.org" ,
Date: 02/09/2014 15:21
Subject: Re: [DFDL-WG] Action 269: clarification on
dfdl:occursIndex() function
Sent by: dfdl-wg-bounces@ogf.org
I am currently implementing functionality in the area where
dfdl:occursIndex( path ) will be in the Daffodil implementation.
It doesn't look very hard to put in a specific argument that is restricted
to be upward only and which identifies exactly which array.
This function is a special case in any DFDL runtime no matter what, and
will require a fair bit of test attention for any implementation so making
it simpler by allowing only the innermost array to be examined isn't
saving a lot of work really.
Question: is a crazy path like ../foo/../../bar/.././.. (which just so
happens to be equivalent to ../../..), a schema definition error?
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
On Tue, Sep 2, 2014 at 9:28 AM, Mike Beckerle
wrote:
________________________________
From: Steve Hanson [smh@uk.ibm.com]
Sent: Monday, September 01, 2014 11:08 AM
To: Mike Beckerle
Subject: Fw: [DFDL-WG] Action 269: clarification on dfdl:occursIndex()
function
269
dfdl:occursIndex() function (Steve)
29/7: Clarify behaviour and decide whether an argument is needed to make
it context independent. Noted that fn:position() also does not take an
argument, but it returns position in current sequence and not position in
array.
4/8: With Steve but consensus is that an argument is needed.
26/8: Mike to review. If an argument is needed, we should make sure this
is in next published spec as the function is used in MIL-STD-2045 schemas.
Regards
Steve Hanson
Architect, IBM DFDL<
http://www.ibm.com/developerworks/library/se-dfdl/index.html>
Co-Chair, OGF DFDL Working Grouphttp://www.ogf.org/dfdl/
IBM SWG, Hursley, UK
smh@uk.ibm.commailto:smh@uk.ibm.com
tel:+44-1962-815848
----- Forwarded by Steve Hanson/UK/IBM on 01/09/2014 16:03 -----
From: Steve Hanson/UK/IBM
To: dfdl-wg@ogf.org,
Cc: dfdl-wg-bounces@ogf.org
Date: 31/07/2014 10:57
Subject: Re: [DFDL-WG] clarification on dfdl:occursIndex() function
________________________________
Note: The reason why fn:position() takes no argument is because it gives
position in the current sequence. Which is also why we have a separate
DFDL specific function dfdl:occursIndex() which is intended for giving
position in enclosing array. I think we need an argument that targets the
specific enclosing array.
Regards
Steve Hanson
Architect, IBM DFDL<
http://www.ibm.com/developerworks/library/se-dfdl/index.html>
Co-Chair, OGF DFDL Working Grouphttp://www.ogf.org/dfdl/
IBM SWG, Hursley, UK
smh@uk.ibm.commailto:smh@uk.ibm.com
tel:+44-1962-815848
From: Tim Kimber/UK/IBM@IBMGB
To: dfdl-wg@ogf.org,
Date: 28/07/2014 23:51
Subject: Re: [DFDL-WG] clarification on dfdl:occursIndex() function
Sent by: dfdl-wg-bounces@ogf.org
________________________________
I agree that it is inconvenient for the 'nearest array parent' to be
inaccessible. However, experience with discriminators makes me fearful of
any rule that includes the phrase 'nearest enclosing' :-)
I think at least one other DFDL function allows the target of the function
to be specified as an argument, but insists that the argument must be in
the dynamic scope of the element ( i.e. its parent/grandparent etc ). I
would be much happier with that solution for occursCountIndex().
I can think of a use case where it may be useful to get a consistent
behaviour for occursCountIndex(). If a DFDL schema is generated from some
other data format description then the model generation code may want to
refer to the nth occurrence of something else in the model, where n is the
occurs index of the current element - regardless of whether this
particular element is an array.
regards,
Tim Kimber,
From: Mike Beckerle
To: "dfdl-wg@ogf.org"
Date: 28/07/2014 23:27
Subject: [DFDL-WG] clarification on dfdl:occursIndex() function
Sent by: dfdl-wg-bounces@ogf.org
________________________________
This function says it can be called on non-array elements. However, it
does not say what the result is.
If called when "." is not itself an array element there are only two
possible behaviors consistent with the fact that it is explicitly allowed
on non-array elements.
The result has to be either
(a) 1
(b) the occursIndex of the nearest enclosing array parent, or 1 if there
is no enclosing array parent.
I claim (a) is fairly pointless. You will just end up having to create
newVariableInstances to carry the array current index downward into
expressions.
I cannot think of a use case where one would want to call occursIndex()
polymorphically, i.e., where you want a number in the case of an array,
but 1 otherwise.
So (b) is the preferable behavior.
Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology |
www.tresys.comhttp://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@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--
dfdl-wg mailing list
dfdl-wg@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
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
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
--
dfdl-wg mailing list
dfdl-wg@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