structure
Class SetList

java.lang.Object
  |
  +--structure.AbstractStructure
        |
        +--structure.AbstractSet
              |
              +--structure.SetList

All Implemented Interfaces:

Set, Structure

public class SetList

extends AbstractSet

Implementation of a set of elements using a list as the underlying storage mechanism. As with the mathematical object, the elements of the set are not duplicated. No order is implied or enforced in this structure, but simple set operations such as intersection, union, difference, and subset are provided.

Example Usage: Given a list of students who completed a computer science thesis in the 2001-2002 academic year at Williams College and a list of graduating computer science majors who are continuing on to graduate school, we could determine which thesis students are planning to attend graduate school as follows:

 public static void main(String[] argv){
	//thesis students in the class of '02
	String[] thesis = new String[]{"Doug", "Evan", "Feng"};
	
	//students continuing on to grad school
	String[] grad = new String[]{"Doug", "Feng", "Lida"};

	//instantiate our sets
	Set thesisSet = new SetList(), 
	    gradSet = new SetList();
		
	//build sets up
	for(int i = 0; i < thesis.length; i++) thesisSet.add(thesis[i]);
	for(int i = 0; i < grad.length; i++) gradSet.add(grad[i]);
	
	//calculate the intersection of the two sets
	thesisSet.retainAll(gradSet);
	System.out.println(thesisSet);
 }
 

Field Summary

protected List

data The underlying structure --- a list.

Constructor Summary

SetList()
Construct a new set list.

Method Summary

void	add(Object e) Add an element to set, if not already present.
void	addAll(Structure other) Compute the union of this set with other.
void	clear() Remove all the elements from the set.
Object	clone() Returns a shallow clone of this set.
boolean	contains(Object e) Returns true if value is an element of the set.
boolean	containsAll(Structure other) Determine if this set is a subset of other.
boolean	isEmpty() Determine if the set is empty.
Iterator	iterator() Construct an traversal to traverse the elements of the set.
Object	remove(Object e) Remove an element from the set.
void	removeAll(Structure other) Compute the difference between two sets.
void	retainAll(Structure other) Compute the intersection of this set and other.
int	size() Determine the number of elements in the set.
String	toString() Construct a string representation of the set.

Methods inherited from class structure.AbstractStructure

elements, hashCode, values

Methods inherited from class java.lang.Object

, equals, finalize, getClass, notify, notifyAll, registerNatives, wait, wait, wait

Methods inherited from interface structure.Structure

elements, values

Field Detail

data

protected List data

The underlying structure --- a list.

Constructor Detail

SetList

public SetList()

Construct a new set list.

Method Detail

clear

public void clear()

Remove all the elements from the set.

Postcondition:

elements of set are removed

isEmpty

public boolean isEmpty()

Determine if the set is empty.

Overrides:

isEmpty in class AbstractStructure

Postcondition:

returns true iff set is empty

Returns:

True iff there are no elements in set.

add

public void add(Object e)

Add an element to set, if not already present.

Parameters:

e - The new value to be added to set.

Precondition:

e is non-null object

Postcondition:

adds element e to interface

remove

public Object remove(Object e)

Remove an element from the set.

Parameters:

e - The element of the set to be removed.

Precondition:

e is non-null object

Postcondition:

e is removed from set, value returned

Returns:

The value actually removed.

contains

public boolean contains(Object e)

Returns true if value is an element of the set.

Overrides:

contains in class AbstractStructure

Parameters:

e - The element sought in set.

Precondition:

e is non-null

Postcondition:

returns true iff e is in set

Returns:

True iff the element is in the set.

containsAll

public boolean containsAll(Structure other)

Determine if this set is a subset of other.

Overrides:

containsAll in class AbstractSet

Parameters:

other - The potential superset.

Precondition:

other is non-null reference to set

Postcondition:

returns true iff this set is subset of other

clone

public Object clone()

Returns a shallow clone of this set.

Overrides:

clone in class Object

Postcondition:

returns a copy of set

Returns:

A new set with same values.

addAll

public void addAll(Structure other)

Compute the union of this set with other. This set not modified.

Overrides:

addAll in class AbstractSet

Parameters:

other - The set to be unioned with this.

Precondition:

other is non-null reference to set

Postcondition:

returns new set containing union of this and other

Returns:

Union of this and other.

retainAll

public void retainAll(Structure other)

Compute the intersection of this set and other. Members of result are in both this and other.

Overrides:

retainAll in class AbstractSet

Parameters:

other - The other set to be intersected with this.

Precondition:

other is non-null reference to set

Postcondition:

returns new set containing intersection of this and other

Returns:

Intersection of this and other.

removeAll

public void removeAll(Structure other)

Compute the difference between two sets. Values of the result are members of this, but not other.

Overrides:

removeAll in class AbstractSet

Parameters:

other - The set whose values are to be eliminated from this.

Precondition:

other is non-null reference to set

Postcondition:

returns new set containing difference of this and other

Returns:

Difference between this and other.

iterator

public Iterator iterator()

Construct an traversal to traverse the elements of the set. Elements will not appear in any particular order.

Postcondition:

returns traversal to traverse the elements of set

Returns:

An traversal for inspecting members of the set.

size

public int size()

Determine the number of elements in the set.

Postcondition:

returns number of elements in set

Returns:

The number of elements in the set.

toString

public String toString()

Construct a string representation of the set.

Overrides:

toString in class Object

Postcondition:

returns a string representation of set

Returns:

A string representing the set.