DFDL WG,

Some questions and feedback on Section 7.3.1 Properties for dfdl:assert.  I don’t think any of these are major issues.

> "Schema authors can insert xs:sequence constructs to control the timing of evaluation of statements more precisely."

An example here would illustrate and clarify the concept.  This same verbiage is used in other sections of the spec, but I would think that only a single example would be sufficient to demonstrate the technique.

Under the “test” property:

> “The expression must have been evaluated by the time this element and it descendents have been processed.”

I’m lost in the grammar here.  Is that equivalent to “The expression must be evaluated before this element and its descendants are fully processed”?  (Changes highlighted).

Also, should the spec define what it means to “process” an element for this statement to have any weight?

> “It is a schema definition error if dfdl:test is the empty string and the value is

not specified and dfdl:testKind is 'expression' or not specified.”

Huh?  If the value of what isn’t specified? The value of the dfdl:assert annotation? 

Under the “testPattern” property:

> “It is a schema definition error if dfdl:testPattern is the empty string and the

value is not specified and dfdl:testKind is 'pattern'.”

Same comment here.  Should this be “… and the value of the dfdl:assert annotation is not specified…”?

> “In order for a testPattern to be used, the data subject to the pattern must be

scannable using a DFDL regular expression otherwise the results are not

predictable.”

What does it mean for data to be “scannable”?  Does this mean that the representation has to be text, since it's the physical representation of the data that is compared to the regular expression? 

Very respectfully,

--

Jonathan W. Cranford

Senior Information Systems Engineer

The MITRE Corporation (http://www.mitre.org)