Re: Missing productions in Core BNF (WD 20 February 2004)?

Hi Jan,

Yes, that is a bug. Good catch. The connection:

ValueExpr -> PathExpr -> RelativePathExpr -> StepExpr -> FilterExpr -> 
PrimaryExpr

was lost. It should be preserved in the XQuery core through:

ValueExpr -> StepExpr -> PrimaryExpr

There is no need for a FilterExpr which would just be a reference to 
PrimaryExpr, but
we need to introduce back the StepExpr as being the union of AxisStep or 
PrimaryExpr.

The corresponding grammar productions should be changed to the following:

ValueExpr  ::=  ValidateExpr | StepExpr
StepExpr  ::=  AxisStep | PrimaryExpr

This will be fixed in the next version of the Formal Semantics document.

Best,
- Jerome




"Sievers, Jan" <[email protected]> 
Sent by: [email protected]
08/25/2004 11:36 AM

To
"www-Ql ([email protected])" <[email protected]>
cc

Subject
Missing productions in Core BNF (WD 20 February 2004)?







Hi everybody,

I am wondering if there are some productions missing in the Core BNF 
defined in "XQuery 1.0 and XPath 2.0 Formal Semantics" (Working Draft 20 
February 2004).

For instance there is no "StepExpr" or "FilterExpr" and the production [53 
(Core)] "PrimaryExpr ::= ..." is never used.

Is this a bug?
Or is there something special about the normalization rules?

Thanks,
Jan Sievers