- All Implemented Interfaces:
- SqlExprEvaluator
public class SqlExprEvaluator_Arithmetic
extends SqlExprEvaluator2
Process for finding the appropriate op:
Given a set of expressions whose datatype is known, do the following:
. a) check if for the opName there exists a method that accepts the given arguments.
. b) if so, check if it has an evaluator attached (this is this object)
. c) check whether the given arguments datatypes are valid according to a datatype system
. d) if all arguments are constants, we can also use Jena to evaluate the expression
ISSUE: step A requires the OpName to be defined with a signature
However, only in step c this is enforced.
So here is the master plan: The point of the "transformation" is to get
rid of all the RDF-term expressions, and instead reduce them to
operations on conventional datatypes.
As such, there are no RDF terms on the SqlExpr level.
- Author:
- Claus Stadler