com.nwawsoft.util.datastructures

Class List

java.lang.Object

com.nwawsoft.util.datastructures.List

Direct Known Subclasses:

IntList, StringList

public class List
extends java.lang.Object

List data structure. Can be used with any object or extended for a specific type as in the examples IntList and StringList.

Constructor Summary

Constructors

Constructor and Description
List() Creates an empty list.

Method Summary

Modifier and Type	Method and Description
void	append(java.lang.Object o) Adds the specified object to the end of the list.
void	clear() Completely empties the list.
void	concat(List l) Concatenates a specified list to the list.
int	count() Deprecated. use getLength() instead to not change the currently selected object.
int	getLength() Returns the amount of elements in the list.
java.lang.Object	getObject() Returns the content of the currently selected object if a currently selected object exists.
boolean	hasAccess() Returns whether a currently selected object exists.
void	insert(java.lang.Object o) If there is a currently selected object the specified element is added before it.
boolean	isEmpty() Returns whether the list is empty.
boolean	isType(java.lang.Class c) Returns whether all contents of the list are objects of the specified class and sets the currently selected object to the first object.
boolean	isTypeOrNull(java.lang.Class c) Returns whether all contents of the list are objects of the specified class or null and sets the currently selected object to the first object.
void	next() If the list is not empty, a currently selected object exists and the currently selected object is not the last element in the list the current pointer moves to the next object.
void	previous() If there is a currently selected object the previous object becomes the currently selected object.
void	print() Prints all entries of the list, one line per entry, using .toString() to get its String representation.
void	remove() If there is a currently selected object it is removed from the list and the object behind it becomes the new currently selected object.
void	reverse() Inverts the list.
void	setObject(java.lang.Object o) Replaces the content of the currently selected object with the specified content if there is any.
boolean	sharesNoEntry(List l) Checks whether the list has no entry that fits Object.equals() for any object in the specified list.
static boolean	sharesNoEntry(List a, List b) Checks whether two lists have no entries that fit Object.equals().
void	toFirst() Moves the currently selected object pointer to the first object of the list.
void	toLast() Moves the currently selected object pointer to the last object of the list.

Methods inherited from class java.lang.Object

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

Constructor Detail

List

public List()

Creates an empty list.

Method Detail

isEmpty

public boolean isEmpty()

Returns whether the list is empty.

Returns:

true if list is empty. Else false.

clear

public void clear()

Completely empties the list.

hasAccess

public boolean hasAccess()

Returns whether a currently selected object exists.

Returns:

true if a currently selected object exists. Else false.

next

public void next()

If the list is not empty, a currently selected object exists and the currently selected object is not the last element in the list the current pointer moves to the next object. If any of these conditions don't apply there will not be a currently selected object after execution.

toFirst

public void toFirst()

Moves the currently selected object pointer to the first object of the list.

toLast

public void toLast()

Moves the currently selected object pointer to the last object of the list.

getObject

public java.lang.Object getObject()

Returns the content of the currently selected object if a currently selected object exists. Else returns null.

Returns:

the content of the currently selected object if a currently selected object exists. Else null.

setObject

public void setObject(java.lang.Object o)

Replaces the content of the currently selected object with the specified content if there is any. If there is none, nothing happens.

Parameters:

o - any object.

append

public void append(java.lang.Object o)

Adds the specified object to the end of the list. The currently selected object remains unchanged. If the list was empty the object is added and there is still no currently selected object. If the specified object is null it is not added.

Parameters:

o - any object.

insert

public void insert(java.lang.Object o)

If there is a currently selected object the specified element is added before it. The currently selected object remains unchanged. If the list is empty the specified object is added and there is still no currently selected object. If there is no currently selected object and the list is non-empty or if the specified object is null nothing happens.

Parameters:

o - any object.

previous

public void previous()

If there is a currently selected object the previous object becomes the currently selected object. If the object was the first object of the list or if there is no currently selected object nothing happens.

concat

public void concat(List l)

Concatenates a specified list to the list. The currently selected object remains unchanged. If the specified list is null or empty nothing happens.

Parameters:

l - any list.

remove

public void remove()

If there is a currently selected object it is removed from the list and the object behind it becomes the new currently selected object. If the last object of the list gets removed there will no longer be a currently selected object. If the list is empty or there is no currently selected object nothing happens.

count

@Deprecated
public int count()

Deprecated. use getLength() instead to not change the currently selected object.

Counts the elements in the list. The currently selected object gets set to the first object of the List.

Returns:

the amount of objects in the list.

getLength

public int getLength()

Returns the amount of elements in the list.

Returns:

the amount of elements in the list.

reverse

public void reverse()

Inverts the list. The new first object becomes the currently selected object.

print

public void print()

Prints all entries of the list, one line per entry, using .toString() to get its String representation.

isTypeOrNull

public boolean isTypeOrNull(java.lang.Class c)

Returns whether all contents of the list are objects of the specified class or null and sets the currently selected object to the first object.

Parameters:

c - an object of the Class to check the list's content objects against.

Returns:

true if all objects are either the specified type or null, false if any element got a different type.

isType

public boolean isType(java.lang.Class c)

Returns whether all contents of the list are objects of the specified class and sets the currently selected object to the first object.

Parameters:

c - an object of the Class to check the list's content objects against.

Returns:

true if all objects are of the specified type, false if any element got a different type.

sharesNoEntry

public static boolean sharesNoEntry(List a,
                                    List b)

Checks whether two lists have no entries that fit Object.equals(). The currently selected object of both lists gets gets set to their respective first elements. Note that this has a run-time of O(a.getLength()*b.getLength()).

Parameters:

a - any list.

b - a second list.

Returns:

true if no match was found. Else false.

sharesNoEntry

public boolean sharesNoEntry(List l)

Checks whether the list has no entry that fits Object.equals() for any object in the specified list. The currently selected object of both lists gets gets set to their respective first elements. Note that this has a run-time of O(length*b.getLength()).

Parameters:

l - any list.

Returns:

true if no match was found. Else false.