This is a static archive of the previous Open Grid Forum Redmine content management system saved from host redmine.ogf.org file /boards/15/topics/97?r=187 at Thu, 03 Nov 2022 15:31:03 GMT Add section for implementation defined limits - Public Comments Archive - Open Grid Forum

Add section for implementation defined limits

Added by Jonathan Cranford about 9 years ago

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. The W3C XQuery 1.0 spec (http://www.w3.org/TR/xquery) and XQuery 1.0 and XPath 2.0 Functions and Operators spec (http://www.w3.org/TR/xpath-functions) similarly defines and delineates implementation-defined features.

Appendix A (http://www.w3.org/TR/xproc/#conformance) contains the following text:

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 <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 section A.2 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 the DFDL spec would provide a great resource for DFDL implementers.


Replies (3)

RE: Add section for implementation defined limits - Added by Steve Hanson about 8 years ago

Add definitions of ‘implementation-defined feature’ and ‘implementation-dependent feature’ to the Glossary.

Implementation-defined feature. A feature where the implementation has discretion in how it is performed, and the implementation must document how it is performed.

Implementation-dependent feature. A feature where the implementation has discretion in how it is performed, but the implementation is not required to document how the feature is performed.

Sections throughout. Correct the specification to use the above terms where needed.

Not necessary to list them all in a separate section.

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This is a static archive of the previous Open Grid Forum Redmine content management system saved from host redmine.ogf.org file /boards/15/topics/97?r=187 at Thu, 03 Nov 2022 15:31:03 GMT