org.jutil.predicate
Class CompositePredicate

java.lang.Object
  |
  +--org.jutil.predicate.AbstractPredicate
        |
        +--org.jutil.predicate.CompositePredicate

All Implemented Interfaces:

CollectionOperator, Predicate

Direct Known Subclasses:

And, Or

public abstract class CompositePredicate

extends AbstractPredicate

A class of predicates that evaluates an object using a number of other predicates.

Field Summary
static java.lang.String	CVS_REVISION

 

Constructor Summary

CompositePredicate()           Initialize a new empty CompositePredicate.

CompositePredicate(Predicate[] predicates)           Initialize a new CompositePredicate with the given predicates.

 

Method Summary
void	add(Predicate predicate)           Add the given predicate to the end of this CompositePredicate.
void	clear()           Clear this CompositePredicate.
java.util.List	getSubPredicates()           See superclass
boolean	isValidElement(java.lang.Object o)           This model method is supplied to make proving the correctness of a subclass easier.
int	nbSubPredicates()           See superclass
Predicate	predicateAt(int index)           Return the index'th subpredicate of this CompositePredicate.
void	removeAll(Predicate predicate)           Remove all occurrences of the given predicate from this CompositePredicate.
void	removedPredicateAt(int index)           Remove the index'th subpredicate from this CompositePredicate.

 

Methods inherited from class org.jutil.predicate.AbstractPredicate

count, equals, exists, filter, forall

 

Methods inherited from class java.lang.Object

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

 

Methods inherited from interface org.jutil.predicate.Predicate

eval

 

Field Detail

CVS_REVISION

public static final java.lang.String CVS_REVISION

CompositePredicate

public CompositePredicate()

Initialize a new empty CompositePredicate.

Specifications:

public behavior
ensures nbSubPredicates() == 0;

CompositePredicate

public CompositePredicate(Predicate[] predicates)

Initialize a new CompositePredicate with the given predicates.

Parameters:

predicates - An array containing the predicates.

Specifications:

public behavior
requires predicates != null;
requires ( \forall int i; i >= 0&&i < predicates.length; predicates[i] != null);
ensures ( \forall int i; i >= 0&&i < predicates.length; getSubPredicates().get(i) == predicates[i]);
ensures nbSubPredicates() == predicates.length;

isValidElement

public boolean isValidElement(java.lang.Object o)

Description copied from interface: CollectionOperator

This model method is supplied to make proving the correctness of a subclass easier. It offers a tunnel for information the caller of methods that operate on the collection.

Most often, this information concerns the type of the elements and them not being null.

The algorithm does not use this method, so we will not force subclasses to implement it. A strengthened specification should be given to enable proving the correctness of a specific operator.

This is actually an abstract precondition as used in Eiffel.

Specifications:

     also

public behavior
ensures \result == ( \forall Predicate p; getSubPredicates().contains(p); p.isValidElement(o));

Specifications inherited from overridden method in interface CollectionOperator:

public behavior
ensures ( \forall Object o1; ; ( \forall Object o2; (o2 != null)&&o2.equals(o1); isValidElement(o1) == isValidElement(o2)));

add

public void add(Predicate predicate)

Add the given predicate to the end of this CompositePredicate.

Parameters:

predicate - The Predicate to add.

Specifications:

public behavior
requires predicate != null;
requires predicate != this;
requires !predicate.getSubPredicates().contains(this);
ensures nbSubPredicates() == \old(nbSubPredicates())+1;
ensures predicateAt(nbSubPredicates()) == predicate;

clear

public void clear()

Clear this CompositePredicate.

Specifications:

public behavior
ensures nbSubPredicates() == 0;

removedPredicateAt

public void removedPredicateAt(int index)

Remove the index'th subpredicate from this CompositePredicate.

Parameters:

index - The index of the predicate to remove.

Specifications:

public behavior
requires index > 0;
requires index <= nbSubPredicates();
ensures nbSubPredicates() == \old(nbSubPredicates())-1;
ensures ( \forall int i; i > index&&i <= \old(nbSubPredicates()); predicateAt(i-1) == \old(predicateAt(i)));

removeAll

public void removeAll(Predicate predicate)

Remove all occurrences of the given predicate from this CompositePredicate.

Parameters:

predicate - The predicate to be removed.

Specifications:

public behavior
ensures ( \forall int i; i > 0&&i < \old(nbSubPredicates()); \old(predicateAt(i)) != predicate ==> (\old(predicateAt(i)) == predicateAt(i-(int)( \num_of int j; j > 0&&j < i; \old(predicateAt(j)) == predicate))));
ensures nbSubPredicates() == \old(nbSubPredicates())-( \num_of int i; i > 0&&i <= \old(nbSubPredicates()); \old(predicateAt(i)) == predicate);
signals (ConcurrentModificationException) (* An exception was raised because another thread was modifying this CompositePredicate*);

predicateAt

public Predicate predicateAt(int index)

Return the index'th subpredicate of this CompositePredicate.

Parameters:

index - The index of the requested predicate.

Specifications:

public behavior
requires index > 0;
requires index <= nbSubPredicates();
ensures \result == getSubPredicates().get(index-1);

getSubPredicates

public java.util.List getSubPredicates()

See superclass

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();