com.hp.hpl.jena.reasoner.rulesys.builtins
Class NoValue

java.lang.Object
  com.hp.hpl.jena.reasoner.rulesys.builtins.BaseBuiltin
      com.hp.hpl.jena.reasoner.rulesys.builtins.NoValue

All Implemented Interfaces:

Builtin

public class NoValue
extends BaseBuiltin

Can be used in two arg form (X, P) or three arg form (X, P, V). In three arg form it succeeds if the triple (X, P, V) is not currently present, in two arg form it succeeds if there is not value for (X, P, *).

Version:

$Revision: 1.1 $ on $Date: 2009-06-29 08:55:36 $

Author:

Dave Reynolds

Field Summary

Fields inherited from class com.hp.hpl.jena.reasoner.rulesys.builtins.BaseBuiltin

BASE_URI

Constructor Summary

NoValue()

Method Summary

boolean	bodyCall(Node[] args, int length, RuleContext context) This method is invoked when the builtin is called in a rule body.
String	getName() Return a name for this builtin, normally this will be the name of the functor that will be used to invoke it.
boolean	isMonotonic() Flag as non-monotonic so the guard clause will get rerun after deferal as part of a non-trivial conflict set.

Methods inherited from class com.hp.hpl.jena.reasoner.rulesys.builtins.BaseBuiltin

checkArgs, getArg, getArgLength, getURI, headAction, isSafe

Methods inherited from class java.lang.Object

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

Constructor Detail

NoValue

public NoValue()

Method Detail

getName

public String getName()

Return a name for this builtin, normally this will be the name of the functor that will be used to invoke it.

bodyCall

public boolean bodyCall(Node[] args,
                        int length,
                        RuleContext context)

This method is invoked when the builtin is called in a rule body.

Specified by:

bodyCall in interface Builtin

Overrides:

bodyCall in class BaseBuiltin

Parameters:

args - the array of argument values for the builtin, this is an array of Nodes, some of which may be Node_RuleVariables.

length - the length of the argument list, may be less than the length of the args array for some rule engines

context - an execution context giving access to other relevant data

Returns:

return true if the buildin predicate is deemed to have succeeded in the current environment

isMonotonic

public boolean isMonotonic()

Flag as non-monotonic so the guard clause will get rerun after deferal as part of a non-trivial conflict set.

Specified by:

isMonotonic in interface Builtin

Overrides:

isMonotonic in class BaseBuiltin