org.jutil.predicate
Class NegationAsFailure

java.lang.Object
  |
  +--org.jutil.predicate.AbstractPredicate
        |
        +--org.jutil.predicate.TotalPredicate
              |
              +--org.jutil.predicate.NegationAsFailure

All Implemented Interfaces:

CollectionOperator, Predicate

public class NegationAsFailure

extends TotalPredicate

A class of predicates that wrap another predicate and treat the occurrence of an exception in eval() as false.

Note that if you wrap a NegationAsFailure object in another predicate, you will not get the same result as when switching the wrapping predicate and the NegationAsFailure. E.g. new Not(new NegationAsFailure(predicate)) will not always return the same value as new NegationAsFailure(new Not(predicate)).

Field Summary
static java.lang.String	CVS_REVISION

 

Constructor Summary

NegationAsFailure(Predicate predicate)           Initialize a new NegationAsFailure with the given predicate.

 

Method Summary
boolean	eval(java.lang.Object object)           Evaluate this Predicate for the given object.
Predicate	getPredicate()           Return the wrapped predicate.
java.util.List	getSubPredicates()           Return the subpredicates of this Predicate.
int	nbSubPredicates()           See superclass

 

Methods inherited from class org.jutil.predicate.TotalPredicate

count, exists, filter, forall, isValidElement

 

Methods inherited from class org.jutil.predicate.AbstractPredicate

equals

 

Methods inherited from class java.lang.Object

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

 

Field Detail

CVS_REVISION

public static final java.lang.String CVS_REVISION

NegationAsFailure

public NegationAsFailure(Predicate predicate)

Initialize a new NegationAsFailure with the given predicate.

Parameters:

predicate - The predicate to be wrapped.

Specifications:

public behavior
requires predicate != null;
ensures getPredicate() == predicate;

eval

public boolean eval(java.lang.Object object)

Description copied from interface: Predicate

Evaluate this Predicate for the given object.

Specifications:

     also

public behavior
ensures getPredicate().isValidElement(object) ==> \result == getPredicate().eval(object);
ensures !getPredicate().isValidElement(object) ==> false;

Specifications inherited from overridden method in class TotalPredicate:

     also

public behavior
signals (Exception) false;

Specifications inherited from overridden method in interface Predicate:

public behavior
ensures \result == true|\result == false;
signals (Exception) !isValidElement(object);

getPredicate

public Predicate getPredicate()

Return the wrapped predicate.

Specifications:

public behavior
ensures \result == getSubPredicates().get(1);

getSubPredicates

public java.util.List getSubPredicates()

Description copied from interface: Predicate

Return the subpredicates of this Predicate.

Specifications:

     also

public behavior
ensures Collections.containsExplicitly(\result ,getPredicate());
ensures \result .size() == 1;

Specifications inherited from overridden method in interface Predicate:

public behavior
ensures \result != null;
ensures !\result .contains(null);
ensures !\result .contains(this);

nbSubPredicates

public int nbSubPredicates()

See superclass

Specifications inherited from overridden method in class AbstractPredicate:
      --- None ---

Specifications inherited from overridden method in interface Predicate:

public behavior
ensures \result == getSubPredicates().size();