org.qedeq.kernel.bo.logic
Class EverythingExists

java.lang.Object
  org.qedeq.kernel.bo.logic.EverythingExists

All Implemented Interfaces:

ClassOperatorExistenceChecker, EqualityOperatorExistenceChecker, ExistenceChecker, FunctionExistenceChecker, PredicateExistenceChecker

public final class EverythingExists

extends Object

implements ExistenceChecker

This implementation gives always the answer true to the question exists this predicate?.

Version:

$Revision: 1.2 $

Method Summary

boolean	classOperatorExists() Check if the class operator is already defined.
boolean	equalityOperatorExists() Check if the equality operator is already defined.
boolean	functionExists(String name, int arguments) Check if a function is already defined.
String	getEqualityOperator() Get equality operator.
static ExistenceChecker	getInstance() Get one instance of this class.
boolean	predicateExists(String name, int arguments) Check if a predicate is already defined.

Methods inherited from class java.lang.Object

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

Method Detail

predicateExists

public boolean predicateExists(String name,
                               int arguments)

Description copied from interface: PredicateExistenceChecker

Check if a predicate is already defined.

Specified by:

predicateExists in interface PredicateExistenceChecker

Parameters:

name - Predicate name.

arguments - Number of operands for the predicate.

Returns:

Predicate is defined.

functionExists

public boolean functionExists(String name,
                              int arguments)

Description copied from interface: FunctionExistenceChecker

Check if a function is already defined.

Specified by:

functionExists in interface FunctionExistenceChecker

Parameters:

name - Function name.

arguments - Number of operands for the function.

Returns:

Functions is defined.

classOperatorExists

public boolean classOperatorExists()

Description copied from interface: ClassOperatorExistenceChecker

Check if the class operator is already defined.

Specified by:

classOperatorExists in interface ClassOperatorExistenceChecker

Returns:

Class operator is defined.

equalityOperatorExists

public boolean equalityOperatorExists()

Description copied from interface: EqualityOperatorExistenceChecker

Check if the equality operator is already defined.

Specified by:

equalityOperatorExists in interface EqualityOperatorExistenceChecker

Returns:

Equality operator is already defined.

getEqualityOperator

public String getEqualityOperator()

Description copied from interface: EqualityOperatorExistenceChecker

Get equality operator. This is the operator string of a predicate.

Specified by:

getEqualityOperator in interface EqualityOperatorExistenceChecker

Returns:

Equality operator. Should be null if !EqualityOperatorExistenceChecker.equalityOperatorExists().

getInstance

public static final ExistenceChecker getInstance()

Get one instance of this class.

Returns:

Class instance.