[F&O] BEA_034

Function and Operators: request for functionality


It is often required to test if a data model instance
would validate correctly, without actually attempting the
validation operation (which, if unsuccessful, raises
an irrecoverable error).

The signature of the function is:

fn:validatesCorrectly($x as node*) as xs:boolean
/* the name doesn't matter of course */

The semantics can be defined in terms of the validate{} expression:
validatesCorrectly($x) returns true if and only if the expression 
validate{$x}
would perform correctly and not would raise a dynamic error.

(As for any other expression) a query processor is allowed to statically
evaluate the function to either true or false if there is guaranteed 
that
the dynamic phase would evaluate it to the same value.

Best regards.

Received on Wednesday, 18 February 2004 15:10:44 UTC