Class DoubleArraySeq - Millersville Variation

java.lang.Object

  extended by edu.colorado.collections.DoubleArraySeq

All Implemented Interfaces:

java.lang.Cloneable

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

This class is a homework assignment. A DoubleArraySeq is a collection of double numbers. The sequence can have a special "current element," which is specified and accessed through four methods that are not available in the bag class (start, getCurrent, advance and isCurrent).

See Also:

Unmodified older Java Source Code developed by Michael Main for this class can be found at (www.cs.colorado.edu/~main/edu/colorado/collections/DoubleArraySeq.java)

Note:

(1) The capacity of a sequence can change after it's created, but the maximum capacity is limited by the amount of free memory on the machine. The constructor, addAfter, addBefore, clone, and concatenation will result in an OutOfMemoryError when free memory is exhausted.

(2) A sequence's capacity cannot exceed the maximum integer 2,147,483,647 (Integer.MAX_VALUE). Any attempt to create a larger capacity results in a failure due to an arithmetic overflow.

DoubleArraySeq

public DoubleArraySeq()

Initialize an empty sequence with an initial capacity of 10. Note that the addAfter and addBefore methods work efficiently (without needing more memory) until this capacity is reached.

Parameters:

- - none

Postcondition:

This sequence is empty and has an initial capacity of 10.

Throws:

java.lang.OutOfMemoryError - Indicates insufficient memory for: new double[10].

DoubleArraySeq

public DoubleArraySeq(int initialCapacity)

Initialize an empty sequence with a specified initial capacity. Note that the addAfter and addBefore methods work efficiently (without needing more memory) until this capacity is reached.

Parameters:

initialCapacity - the initial capacity of this sequence

Precondition:

initialCapacity is non-negative.

Postcondition:

This sequence is empty and has the given initial capacity.

Throws:

java.lang.IllegalArgumentException - Indicates that initialCapacity is negative.

java.lang.OutOfMemoryError - Indicates insufficient memory for: new double[initialCapacity].

addAfter

public void addAfter(double element)

Add a new element to this sequence, after the current element. If the new element would take this sequence beyond its current capacity, then the capacity is increased before adding the new element.

Parameters:

element - the new element that is being added

Postcondition:

A new copy of the element has been added to this sequence. If there was a current element, then the new element is placed after the current element. If there was no current element, then the new element is placed at the end of the sequence. In all cases, the new element becomes the new current element of this sequence.

Throws:

java.lang.OutOfMemoryError - Indicates insufficient memory for increasing the sequence's capacity.

Note:

An attempt to increase the capacity beyond Integer.MAX_VALUE will cause the sequence to fail with an arithmetic overflow.

addBefore

public void addBefore(double element)

Add a new element to this sequence, before the current element. If the new element would take this sequence beyond its current capacity, then the capacity is increased before adding the new element.

Parameters:

element - the new element that is being added

Postcondition:

A new copy of the element has been added to this sequence. If there was a current element, then the new element is placed before the current element. If there was no current element, then the new element is placed at the start of the sequence. In all cases, the new element becomes the new current element of this sequence.

Throws:

java.lang.OutOfMemoryError - Indicates insufficient memory for increasing the sequence's capacity.

Note:

An attempt to increase the capacity beyond Integer.MAX_VALUE will cause the sequence to fail with an arithmetic overflow.

addAll

public void addAll(DoubleArraySeq addend)

Place the contents of another sequence at the end of this sequence.

Parameters:

addend - a sequence whose contents will be placed at the end of this sequence

Precondition:

The parameter, addend, is not null.

Postcondition:

The elements from addend have been placed at the end of this sequence. The current element of this sequence remains where it was, and the addend is also unchanged.

Throws:

java.lang.NullPointerException - Indicates that addend is null.

java.lang.OutOfMemoryError - Indicates insufficient memory to increase the size of this sequence.

Note:

An attempt to increase the capacity beyond Integer.MAX_VALUE will cause an arithmetic overflow that will cause the sequence to fail.

advance

public void advance()

Move forward, so that the current element is now the next element in this sequence.

Parameters:

- - none

Precondition:

isCurrent() returns true.

Postcondition:

If the current element was already the end element of this sequence (with nothing after it), then there is no longer any current element. Otherwise, the new element is the element immediately after the original current element.

Throws:

java.lang.IllegalStateException - Indicates that there is no current element, so advance may not be called.

clone

public DoubleArraySeq clone()

Generate a separate copy of this sequence.

Overrides:

clone in class java.lang.Object

Parameters:

- - none

Returns:

The return value is a copy of this sequence. Subsequent changes to the copy will not affect the original, nor vice versa.

Throws:

java.lang.OutOfMemoryError - Indicates insufficient memory for creating the clone.

concatenation

public static DoubleArraySeq concatenation(DoubleArraySeq s1,
                                        DoubleArraySeq s2)

Create a new sequence that contains all the elements from one sequence followed by another.

Parameters:

s1 - the first of two sequences

s2 - the second of two sequences

Precondition:

Neither s1 nor s2 is null.

Returns:

a new sequence that has the elements of s1 followed by the elements of s2 (with no current element)

Throws:

NullPointerException. - Indicates that one of the arguments is null.

java.lang.OutOfMemoryError - Indicates insufficient memory for the new sequence.

Note:

An attempt to create a sequence with a capacity beyond Integer.MAX_VALUE will cause an arithmetic overflow that will cause the sequence to fail.

ensureCapacity

public void ensureCapacity(int minimumCapacity)

Change the current capacity of this sequence.

Parameters:

minimumCapacity - the new capacity for this sequence

Postcondition:

This sequence's capacity has been changed to at least minimumCapacity. If the capacity was already at or greater than minimumCapacity, then the capacity is left unchanged.

Throws:

java.lang.OutOfMemoryError - Indicates insufficient memory for: new int[minimumCapacity].

getCapacity

public int getCapacity()

Accessor method to get the current capacity of this sequence. The add method works efficiently (without needing more memory) until this capacity is reached.

Parameters:

- - none

Returns:

the current capacity of this sequence

getCurrent

public double getCurrent()

Accessor method to get the current element of this sequence.

Parameters:

- - none

Precondition:

isCurrent() returns true.

Returns:

the current element of this sequence

Throws:

java.lang.IllegalStateException - Indicates that there is no current element, so getCurrent may not be called.

isCurrent

public boolean isCurrent()

Accessor method to determine whether this sequence has a specified current element that can be retrieved with the getCurrent method.

Parameters:

- - none

Returns:

true (there is a current element) or false (there is no current element at the moment)

removeCurrent

public void removeCurrent()

Remove the current element from this sequence.

Parameters:

- - none

Precondition:

isCurrent() returns true.

Postcondition:

The current element has been removed from this sequence, and the following element (if there is one) is now the new current element. If there was no following element, then there is now no current element.

Throws:

java.lang.IllegalStateException - Indicates that there is no current element, so removeCurrent may not be called.

size

public int size()

Determine the number of elements in this sequence.

Parameters:

- - none

Returns:

the number of elements in this sequence

start

public void start()

Set the current element at the front of this sequence.

Parameters:

- - none

Postcondition:

The front element of this sequence is now the current element (but if this sequence has no elements at all, then there is no current element).

toString

public java.lang.String toString()

Provide a string representation of the sequence with current item in parentheses

Overrides:

toString in class java.lang.Object

Parameters:

- - none

Returns:

string displaying sequence

trimToSize

public void trimToSize()

Reduce the current capacity of this sequence to its actual size (i.e., the number of elements it contains). The current item does not change.

Parameters:

- - none

Postcondition:

This sequence's capacity has been changed to its current size.

Throws:

java.lang.OutOfMemoryError - Indicates insufficient memory for altering the capacity.