SAG-FO-03: Overlap between documents

Software AG feels that the complete set of specifications for XQuery and
XPath is considerably larger than it needs to be. The documentation is not
structured to meet the needs of its intended readership, and a great deal of
material is contained in more than one place, leading to the risk of
inconsistency.

We intend to comment separately on each document to indicate how we think
this problem can be addressed. 

In the case of Functions and Operators, we make the following suggestions:

(a) The specification of all operators should go in the XPath/XQuery
language book at the point where the operator is introduced. The split
between the language book and F&O serves no useful purpose for the reader,
and greatly increases the risk of inconsistencies and errors.

(b) The specification of casting should be moved from Functions and
Operators to the XPath/XQuery language book. At present there seems to be a
significant overlap between section 3.12.3 of the language book and section
17 of F&O, but they use completely different language, so it is impossible
to determine whether they are equivalent.

(c) Where functions have special-case rules for static type inference, this
should be described in F&O rather than in the formal semantics book. In
other words, section 6.2 of the formal semantics document should be
rewritten in language that is accessible to professional software engineers,
and should be moved to F&O.

Michael Kay

Received on Tuesday, 10 June 2003 11:49:48 UTC