ESC/Java2
© 2003,2004,2005 David Cok and Joseph Kiniry
© 2005 UCD Dublin
© 2003,2004 Radboud University Nijmegen
© 1999,2000 Compaq Computer Corporation
© 1997,1998,1999 Digital Equipment Corporation
All Rights Reserved

javafe.util
Class Set

java.lang.Object
  extended byjavafe.util.Set
All Implemented Interfaces:
java.lang.Cloneable

public class Set
extends java.lang.Object
implements java.lang.Cloneable

A simple implementation of imperative sets. Set's may not contain null.


Field Summary
private  java.util.Hashtable ht
          We contain the element e iff ht has the mapping e -> e.
 
Constructor Summary
Set()
          Create an empty set
Set(java.util.Enumeration e)
          Create a set from the elements of an Enumeration
 
Method Summary
 boolean add(java.lang.Object o)
          Add an element Return 'true' iff the element was already in the set.
 void addEnumeration(java.util.Enumeration e)
          Add all the elements of a given enumeration
 void clear()
          Remove all our elements
 java.lang.Object clone()
           
 boolean contains(java.lang.Object o)
          Do we contain a particular element?
 boolean containsAny(Set s)
          Returns whether or not the set has any element in common with s.
 java.util.Enumeration elements()
          Return an enumeration of our elements
 void intersect(Set s)
          Remove all elements not contained in another set.
 boolean isEmpty()
          Do we contain no elements?
 boolean remove(java.lang.Object o)
          Remove a particular element if we contain it.
 int size()
          Return the number of elements we hold.
 java.lang.String toString()
           
 boolean union(Set s)
          Adds all elements in another set.
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

ht

private java.util.Hashtable ht
We contain the element e iff ht has the mapping e -> e.

All mappings of ht are of the form e' -> e' for some e'.

Constructor Detail

Set

public Set()
Create an empty set


Set

public Set(java.util.Enumeration e)
Create a set from the elements of an Enumeration

Method Detail

size

public int size()
Return the number of elements we hold.


isEmpty

public boolean isEmpty()
Do we contain no elements?


contains

public boolean contains(java.lang.Object o)
Do we contain a particular element?


elements

public java.util.Enumeration elements()
Return an enumeration of our elements


toString

public java.lang.String toString()

clear

public void clear()
Remove all our elements


add

public boolean add(java.lang.Object o)
Add an element Return 'true' iff the element was already in the set.


addEnumeration

public void addEnumeration(java.util.Enumeration e)
Add all the elements of a given enumeration


remove

public boolean remove(java.lang.Object o)
Remove a particular element if we contain it. Return true iff the element was previously in the set.


intersect

public void intersect(Set s)
Remove all elements not contained in another set. This has the effect of setting us to the intersection of our original value and the other set.


union

public boolean union(Set s)
Adds all elements in another set. This has the effect of setting us to the union of our original value and the other set. Return true if any values were added.


containsAny

public boolean containsAny(Set s)
Returns whether or not the set has any element in common with s. Thus, if the intersection of the sets is empty, that is, if the sets are disjoint, then false is returned. The operation leaves both sets unchanged.


clone

public java.lang.Object clone()

ESC/Java2
© 2003,2004,2005 David Cok and Joseph Kiniry
© 2005 UCD Dublin
© 2003,2004 Radboud University Nijmegen
© 1999,2000 Compaq Computer Corporation
© 1997,1998,1999 Digital Equipment Corporation
All Rights Reserved

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