org.openanzo.glitter.expression
Class BinaryFunction

java.lang.Object
  org.openanzo.glitter.expression.FunctionBase
      org.openanzo.glitter.expression.BinaryFunction

All Implemented Interfaces:

Function, FunctionOnValues

Direct Known Subclasses:

BooleanEq, BooleanGe, BooleanGt, BooleanLe, BooleanLt, BooleanNe, DateTimeEq, DateTimeGe, DateTimeGt, DateTimeLe, DateTimeLt, DateTimeNe, LangMatches, NumericAdd, NumericDivide, NumericEq, NumericGe, NumericGt, NumericLe, NumericLt, NumericMultiply, NumericNe, NumericSubtract, RDFTermEq, RDFTermNe, SameTerm, StringLiteralGe, StringLiteralGt, StringLiteralLe, StringLiteralLt

public abstract class BinaryFunction
extends FunctionBase
implements FunctionOnValues

BinaryFunction is a base class for SPARQL functions that take two arguments. It checks the number of arguments supplied and defers to an abstract method call(RDFTerm, RDFTerm) that unpackages the binary arguments from the original argument list.

Author:

lee

Constructor Summary

BinaryFunction()

Method Summary

RDFTerm	call(java.util.List<RDFTerm> arguments) Invokes the function and determines a return value.
abstract RDFTerm	call(RDFTerm arg1, RDFTerm arg2) Invoke a binary function explicitly with two arguments.

Methods inherited from class org.openanzo.glitter.expression.FunctionBase

compareBooleans, compareBooleans, compareDateTimes, compareNumerics, compareStringLiterals, operatesOnTypeErrors, operatesOnValues

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.openanzo.glitter.expression.Function

getIdentifier, operatesOnTypeErrors, operatesOnValues

Constructor Detail

BinaryFunction

public BinaryFunction()

Method Detail

call

public RDFTerm call(java.util.List<RDFTerm> arguments)
             throws ExpressionEvaluationException

Description copied from interface: FunctionOnValues

Invokes the function and determines a return value.

Specified by:

call in interface FunctionOnValues

Parameters:

arguments - The (evaluated) RDF terms being passed to the function

Returns:

The result of evaluating this function against the given arguments

Throws:

ExpressionEvaluationException - For invalid types, or other expression evalutaion problems

call

public abstract RDFTerm call(RDFTerm arg1,
                             RDFTerm arg2)
                      throws ExpressionEvaluationException

Invoke a binary function explicitly with two arguments. Subclasses need only implement this method and are assured that they will receive exactly two arguments.

Parameters:

arg1 - First argument to the function

arg2 - Second argument to the function

Returns:

The return value of the function

Throws:

ExpressionEvaluationException