-----Original Message----- From: Steve Hanson [mailto:smh@uk.ibm.com] Sent: Wednesday, September 18, 2013 3:30 AM To: Cranford, Jonathan W. Cc: dfdl-wg@ogf.org; dfdl-wg-bounces@ogf.org Subject: Re: [DFDL-WG] action 224: add section for implementation defined
Jonathan We discussed your definitions on the call. I realise that these are lifted from XProc, but both Mike and I had to a double take on first reading, because the 1st sentence is the same for each. So how about: [Definition: An implementation-defined feature is one where the implementation has discretion in how it is performed, and the implementation must document how it is performed.] [Definition: An implementation-dependent feature is one where the implementation has discretion in how it is performed, but the implementation is not required to document how the feature is performed.] Note that I have re-ordered the definitions as well. Regards Steve Hanson Architect, IBM Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh@uk.ibm.com tel:+44-1962-815848 From: "Cranford, Jonathan W." <jcranford@mitre.org> To: Steve Hanson/UK/IBM@IBMGB, Cc: "dfdl-wg@ogf.org" <dfdl-wg@ogf.org> Date: 19/10/2013 18:59 Subject: RE: [DFDL-WG] action 224: add section for implementation defined limits All, Attached are the first few implementation-specific features divided up between implementation-defined and implementation-dependent features. Three are implementation-defined and two are implementation-dependent. The intent is to add two definitions to the spec, similar to this snippet from the XProc specification (http://www.w3.org/TR/xproc/#conformance): Conformant processors must implement all of the features described in this specification except those that are explicitly identified as optional. Some aspects of processor behavior are not completely specified; those features are either implementation-dependent or implementation-defined. [Definition: An implementation-dependent feature is one where the implementation has discretion in how it is performed. Implementations are not required to document or explain how implementation-dependent features are performed.] [Definition: An implementation-defined feature is one where the implementation has discretion in how it is performed. Conformant implementations must document how implementation-defined features are performed.] I'm still working through the spec; I thought I'd send these off now to begin discussion. Fyi, Jonathan limits
Jonathan
Thanks for citing that example. I have added a summary to the minutes of yesterday's WG call.
Please go ahead and trawl the document for implementation
things.
Please also raise a public comment to track, at http://redmine.ogf.org/projects/editor-pubcom/boards/15 <http://redmine.ogf.org/projects/editor-pubcom/boards/15> .
Regards
Steve Hanson Architect, IBM Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group <http://www.ogf.org/dfdl/> IBM SWG, Hursley, UK smh@uk.ibm.com <mailto:smh@uk.ibm.com> tel:+44-1962-815848
From: "Cranford, Jonathan W." <jcranford@mitre.org> To: "dfdl-wg@ogf.org" <dfdl-wg@ogf.org>, Date: 17/09/2013 16:11 Subject: [DFDL-WG] action 224: add section for implementation defined limits Sent by: dfdl-wg-bounces@ogf.org
________________________________
All,
Action item 224 was raised two weeks ago during the WG call.
224 Add section for implementation defined limits (All) 3/9: Several places in the spec cite this, should be grouped. Currently
listed in section 2.6. Also note distinction between 'implementation defined' and 'implementation dependent'. Check spec for correct usage. Resolve during public comment.
The action item was created based on a comment I made during the call, so I thought it’d be good to provide an example of the distinction I was
make.
The W3C XProc specification does a great job of differentiating between implementation-defined and implementation-dependent features, with a convenient list of each in the appendix.
Appendix A (http://www.w3.org/TR/xproc/#conformance <http://www.w3.org/TR/xproc/#conformance> ) contains the following text. Conformant processors must implement all of the features described in
specification except those that are explicitly identified as optional. Some aspects of processor behavior are not completely specified; those features are either implementation-dependent <http://www.w3.org/TR/xproc/#dt- implementation-dependent> or implementation-defined <http://www.w3.org/TR/xproc/#dt-implementation-defined> . [Definition: An implementation-dependent feature is one where the implementation has discretion in how it is performed. Implementations are not required to document or explain how implementation-dependent <http://www.w3.org/TR/xproc/#dt-implementation-dependent> features are performed.] [Definition: An implementation-defined feature is one where the implementation has discretion in how it is performed. Conformant implementations must document how implementation-defined <http://www.w3.org/TR/xproc/#dt- implementation-defined> features are performed.]
Section A.1 then lists all the implementation-defined features, and
lists all the implementation-dependent features.
I think the XProc spec provides a great example to follow on two counts. First, it formally distinguishes between implementation-defined and implementation- dependent features. The choice of terms isn’t nearly as important as the distinction itself, of course: implementations must document how certain features are implemented. In the DFDL realm, section 2.6 lists some implementation limits which always constitute schema definition errors; surely these are the types of details that must be documented by any DFDL implementation. Using terminology such as “implementation-defined” and “implementation-dependent” would flag these types of documentation requirements for implementations within the specification.
Second, all the implementation-defined and implementation-dependent features are listed in one place in the specification. I think doing the same in
spec would provide a great resource for DFDL implementers.
Comments? If everyone agrees, I don’t mind taking the action to search
defined/dependent partially trying to this section A.2 the DFDL through
the document looking for candidates for inclusion in such a list.
Sincerely,
-- Jonathan W. Cranford Senior Information Systems Engineer The MITRE Corporation (http://www.mitre.org <http://www.mitre.org/> ) -- dfdl-wg mailing list dfdl-wg@ogf.org https://www.ogf.org/mailman/listinfo/dfdl-wg <https://www.ogf.org/mailman/listinfo/dfdl-wg>
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