org.zedlib
Class HashBag

java.lang.Object
  java.util.AbstractCollection
      java.util.AbstractSet
          java.util.HashSet
              org.zedlib.HashSet
                  org.zedlib.HashRel
                      org.zedlib.HashFun
                          org.zedlib.HashBag

All Implemented Interfaces:

Bag, Cloneable, Collection, Function, Relation, Serializable, Set, Set

public class HashBag

extends HashFun

implements Bag

Bags are collections of elements of X in which the number of times an element occurs is significant.

Author:

Brad Long

See Also:

Serialized Form

Constructor Summary

HashBag()

HashBag(Bag b)
Constructs a bag from another given bag.

HashBag(Collection c)
Constructs a bag by iterating over a given collection.

HashBag(Map m)
Constructs a bag by iterating over a given map.

Method Summary

boolean	add(Baglet b) Adds a maplet to this bag.
boolean	add(Maplet m) Adds a maplet to this bag.
boolean	add(Object o) Adds an object to this bag.
boolean	add(Object x, int y) Adds an object to this bag with the specified number of occurrences.
boolean	containsMember(Object x) Determines whether an object is in the bag.
boolean	containsValue(int count) A convenience function for the alternative range().contains(new Integer(count)).
int	getCount(Object o) Counts the number of times an element appears in this bag.
protected Set	getInstance()
protected Set	getInstance(Set s)
boolean	isSubBagOf(Bag c) Determines whether this bag is a sub-bag of a given bag.
Object	put(Object x, int y) Adds an object to this bag with the specified number of occurrences.
boolean	remove(Object o) Removes an occurrence of the given object from this function.

Methods inherited from class org.zedlib.HashFun

containsKey, containsValue, getMaplet, getValue, put, put

Methods inherited from class org.zedlib.HashRel

add, addAll, addAll, buildRelation, composition, domain, domainAntiRestriction, domainRestriction, image, inverse, isFunction, isInjection, isReflexive, override, range, rangeAntiRestriction, rangeRestriction, toString, transitiveClosure

Methods inherited from class org.zedlib.HashSet

cartesianProduct, difference, difference, identity, intersection, intersection, isProperSubsetOf, isSubsetOf, isSupersetOf, union, union

Methods inherited from class java.util.HashSet

clear, clone, contains, isEmpty, iterator, size

Methods inherited from class java.util.AbstractSet

equals, hashCode, removeAll

Methods inherited from class java.util.AbstractCollection

containsAll, retainAll, toArray, toArray

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.zedlib.Function

containsKey, containsValue, getMaplet, put

Methods inherited from interface org.zedlib.Relation

add, addAll, composition, domain, domainAntiRestriction, domainRestriction, image, inverse, isFunction, isInjection, isReflexive, override, range, rangeAntiRestriction, rangeRestriction, transitiveClosure

Methods inherited from interface org.zedlib.Set

cartesianProduct, difference, identity, intersection, isSubsetOf, isSupersetOf, union

Methods inherited from interface java.util.Set

addAll, clear, contains, containsAll, equals, hashCode, isEmpty, iterator, removeAll, retainAll, size, toArray, toArray

Constructor Detail

HashBag

public HashBag()

HashBag

public HashBag(Collection c)

Constructs a bag by iterating over a given collection.

HashBag

public HashBag(Map m)

Constructs a bag by iterating over a given map.

Throws:

ClassCastException - if any value in the map is not an Integer

HashBag

public HashBag(Bag b)

Constructs a bag from another given bag.

Method Detail

getInstance

protected Set getInstance()

Overrides:

getInstance in class HashFun

getInstance

protected Set getInstance(Set s)

Overrides:

getInstance in class HashFun

getCount

public int getCount(Object o)

Counts the number of times an element appears in this bag.

Specified by:

getCount in interface Bag

Parameters:

o - the object for which to count occurrences

Returns:

the number of times the given key appears in the bag

remove

public boolean remove(Object o)

Removes an occurrence of the given object from this function.

Specified by:

remove in interface Set

Parameters:

o - the object to remove

Returns:

true if an object was removed

containsValue

public boolean containsValue(int count)

A convenience function for the alternative range().contains(new Integer(count)).

Specified by:

containsValue in interface Bag

Parameters:

count - any integer being the number of occurrences to check for

Returns:

true if at least one object exists in the bag occurrence times.

add

public boolean add(Object o)

Adds an object to this bag.

Specified by:

add in interface Set

Overrides:

add in class HashRel

Parameters:

o - the object to add

Returns:

true if the object was added.

add

public boolean add(Baglet b)

Adds a maplet to this bag.

Specified by:

add in interface Bag

Parameters:

b - the baglet to add

Returns:

true if the maplet was added or false if the maplet already exists or number of occurrences given is less then one.

Throws:

ClassCastException - if y in the maplet (x,y) is not an Integer

See Also:

Set.add(Object o)

add

public boolean add(Maplet m)

Adds a maplet to this bag.

Specified by:

add in interface Relation

Overrides:

add in class HashFun

Parameters:

m - the maplet to add

Returns:

true if the maplet was added or false if the maplet already exists or number of occurrences given is less then one.

Throws:

ClassCastException - if y in the maplet (x,y) is not an Integer

add

public boolean add(Object x,
                   int y)

Adds an object to this bag with the specified number of occurrences.

Specified by:

add in interface Bag

Parameters:

x - the object to add

y - the number of times the object should appear in the bag

Returns:

true if the maplet was added

put

public Object put(Object x,
                  int y)

Adds an object to this bag with the specified number of occurrences.

Specified by:

put in interface Bag

Parameters:

x - the object to add

y - the number of times the object should appear in the bag

Returns:

the Integer object that was replaced or null if x was not previously in the bag or occurrences is less then one.

containsMember

public boolean containsMember(Object x)

Determines whether an object is in the bag. The relationship B.containsMember(x) holds exactly if x appears in B a non-zero number of times.

Specified by:

containsMember in interface Bag

Parameters:

x - the object to check for existence

Returns:

true if the object is in the bag

isSubBagOf

public boolean isSubBagOf(Bag c)

Determines whether this bag is a sub-bag of a given bag. A bag B is a sub-bag of another bag C if each element occurs in B no more often than it occurs in C.

Specified by:

isSubBagOf in interface Bag

Parameters:

c - any bag

Returns:

true if this bag is a sub-bag of c