structure
Class MapList

java.lang.Object
  |
  +--structure.MapList

All Implemented Interfaces:

Map

public class MapList

extends Object

implements Map

Associations establish a link between a key and a value. An associative array or map is a structure that allows a disjoint set of keys to become associated with an arbitrary set of values. The convenience of an associative array is that the values used to index the elements need not be comparable and their range need not be known ahead of time. Furthermore, there is no upper bound on the size of the structure. It is able to maintain an arbitrary number of different pieces of information simultaneously. Maps are sometimes called dictionaries because of the uniqueness of the association of words and definitions in a household dictionary.

This implementation is based on a list, so performance for most operations is linear.

Example Usage:

To create a dictionary by reading a collection of words and definitions from System.in we could use the following!

 public static void main (String[] argv){
	Map dict = new MapList();
	ReadStream r = new ReadStream();
	String word, def;
	System.out.println("Enter a word: ");
	while(!r.eof()){
	    word = r.readLine();
	    System.out.println("Enter a definition: ");
	    def = r.readLine();
	    dict.put(word,def);
	    System.out.println("Enter a word: ");
	}
	System.out.println(dict);
 }
 

Field Summary

protected List

data List for storing the entries in this map

Constructor Summary

MapList()
Construct an empty map, based on a list

MapList(Map source)
Construct a map with values found in source

Method Summary

void	clear()
boolean	containsKey(Object k)
boolean	containsValue(Object v)
Set	entrySet()
boolean	equals(Object other)
Object	get(Object k)
int	hashCode()
boolean	isEmpty()
Set	keySet()
Object	put(Object k, Object v)
void	putAll(Map other)
Object	remove(Object k)
int	size() Returns the number of entries in the map
Structure	values()

Methods inherited from class java.lang.Object

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

Field Detail

data

protected List data

List for storing the entries in this map

Constructor Detail

MapList

public MapList()

Construct an empty map, based on a list

MapList

public MapList(Map source)

Construct a map with values found in source

Method Detail

size

public int size()

Returns the number of entries in the map

Specified by:

size in interface Map

Postcondition:

returns the number of entries in the map

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map

Postcondition:

returns true iff this map does not contains any entries

containsKey

public boolean containsKey(Object k)

Specified by:

containsKey in interface Map

Precondition:

k is non-null

Postcondition:

returns true iff k is a key that is mapped to a value; that is, k is in the domain of the map

containsValue

public boolean containsValue(Object v)

Specified by:

containsValue in interface Map

Precondition:

v is non-null

Postcondition:

returns true iff v is the target of at least one map entry; that is, v is in the range of the map

get

public Object get(Object k)

Specified by:

get in interface Map

Precondition:

k is a key, possibly in the map

Postcondition:

returns the value mapped to from k, or null

put

public Object put(Object k,
                  Object v)

Specified by:

put in interface Map

Precondition:

k and v are non-null

Postcondition:

inserts a mapping from k to v in the map

remove

public Object remove(Object k)

Specified by:

remove in interface Map

Precondition:

k is non-null

Postcondition:

removes any mapping from k to a value, from the mapping

putAll

public void putAll(Map other)

Specified by:

putAll in interface Map

Precondition:

other is non-null

Postcondition:

all the mappings of other are installed in this map, overriding any conflicting maps

clear

public void clear()

Specified by:

clear in interface Map

Postcondition:

removes all map entries associated with this map

keySet

public Set keySet()

Specified by:

keySet in interface Map

Postcondition:

returns a set of all keys associated with this map

values

public Structure values()

Specified by:

values in interface Map

Postcondition:

returns a structure that contains the range of the map

entrySet

public Set entrySet()

Specified by:

entrySet in interface Map

Postcondition:

returns a set of (key-value) pairs, generated from this map

equals

public boolean equals(Object other)

Specified by:

equals in interface Map

Overrides:

equals in class Object

Precondition:

other is non-null

Postcondition:

returns true iff maps this and other are entry-wise equal

hashCode

public int hashCode()

Specified by:

hashCode in interface Map

Overrides:

hashCode in class Object

Postcondition:

returns a hash code associated with this structure