org.python.core
Class AbstractArray

java.lang.Object
  org.python.core.AbstractArray

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

PyObjectArray

public abstract class AbstractArray

extends java.lang.Object

implements java.io.Serializable

Abstract class that manages bulk structural and data operations on arrays, defering type-specific element-wise operations to the subclass. Subclasses supply the underlying array and the type-specific operations--greatly reducing the need for casting (thus achieving array-like performances with collection-like flexibility). Also includes functionality to support integration with the the jdk's collections (via methods that return a modification increment).

Subclasses will want to provide the following methods (which are not declared in this class since subclasses should specify the explicit return type):

• <type> get(int)
• void set(int, <type>)
• void add(<type>)
• void add(int, <type>)
• <type>[] toArray()

Clone cannot be supported since the array is not held locally. But the @link #AbstractArray(AbstractArray) constructor can be used for suclasses that need to support clone.

This "type-specific collections" approach was originally developed by Dennis Sosnoski, who provides a more complete library at the referenced URL. Sosnoski's library does not integrate with the jdk collection classes but provides collection-like classes.

Author:

Clark Updike

See Also:

Sosnoski's Type-Specific Collection Library, Serialized Form

Constructor Summary

AbstractArray(AbstractArray toCopy)
Since AbstractArray can support a clone method, this facilitates sublcasses that want to implement clone (poor man's cloning).

AbstractArray(java.lang.Class type)
Creates the managed array with a default size of 10.

AbstractArray(java.lang.Class type, int size)
Creates the managed array with the specified size.

AbstractArray(java.lang.Class type, int[] dimensions)
Construtor for multi-dimensional array types.

AbstractArray(int size)
Use when the subclass has a preexisting array.

Method Summary

void	appendArray(java.lang.Object ofArrayType) Appends the supplied array, which must be an array of the same type as this, to the end of this.
void	clear() Set the array to the empty state, clearing all the data out and nulling objects (or "zero-ing" primitives).
java.lang.Object	copyArray() Constructs and returns a simple array containing the same data as held in this growable array.
int	getModCountIncr() Returns the modification count increment, which is used by AbstractList subclasses to adjust modCount AbstractList uses it's modCount field to invalidate concurrent operations (like iteration) that should fail if the underlying array changes structurally during the operation.
int	getSize() Get the number of values currently present in the array.
void	remove(int index) Remove a value from the array.
void	remove(int start, int stop) Removes a range from the array at the specified indices.
void	replaceSubArray(int thisStart, int thisStop, java.lang.Object srcArray, int srcStart, int srcStop) Replace a range of this array with another subarray.
void	replaceSubArray(java.lang.Object array, int atIndex) Allows an array type to overwrite a segment of the array.
void	setSize(int count) Sets the number of values currently present in the array.
java.lang.String	toString() Provides a default comma-delimited representation of array.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

AbstractArray

public AbstractArray(AbstractArray toCopy)

Since AbstractArray can support a clone method, this facilitates sublcasses that want to implement clone (poor man's cloning). Sublclasses can then do this:

 public MyManagedArray(MyManagedArray toCopy) {
 super(this);
 this.baseArray = ()toCopy.copyArray();
 this.someProp = toCopy.someProp;
 
 }
 

 public Object clone() {
 return new MyManagedArray(this);
 }
 

Parameters:

toCopy -

AbstractArray

public AbstractArray(int size)

Use when the subclass has a preexisting array.

Parameters:

size - the initial size of the array

AbstractArray

public AbstractArray(java.lang.Class type)

Creates the managed array with a default size of 10.

Parameters:

type - array element type (primitive type or object class)

AbstractArray

public AbstractArray(java.lang.Class type,
                     int[] dimensions)

Construtor for multi-dimensional array types. For example, char[][]. This class only manages the top level dimension of the array. For single dimension arrays (the more typical usage), use the other constructors.

Parameters:

type - Array element type (primitive type or object class).

dimensions - An int array specifying the dimensions. For a 2D array, something like new int[] {10,0} to create 10 elements each of which can hold an reference to an array of the same type.

See Also:

Array.newInstance(java.lang.Class, int[])

AbstractArray

public AbstractArray(java.lang.Class type,
                     int size)

Creates the managed array with the specified size.

Parameters:

type - array element type (primitive type or object class)

size - number of elements initially allowed in array

Method Detail

appendArray

public void appendArray(java.lang.Object ofArrayType)

Appends the supplied array, which must be an array of the same type as this, to the end of this.

AbstractList subclasses should update their modCount after calling this method.

Parameters:

ofArrayType - the array to append

clear

public void clear()

Set the array to the empty state, clearing all the data out and nulling objects (or "zero-ing" primitives).

Note: This method does not set modCountIncr to 1 even though java.util.ArrayList would.

AbstractList subclasses should update their modCount after calling this method.

copyArray

public java.lang.Object copyArray()

Constructs and returns a simple array containing the same data as held in this growable array.

Returns:

array containing a shallow copy of the data.

remove

public void remove(int index)

Remove a value from the array. All values above the index removed are moved down one index position.

AbstractList subclasses should always increment their modCount method after calling this, as remove always causes a structural modification.

Parameters:

index - index number of value to be removed

remove

public void remove(int start,
                   int stop)

Removes a range from the array at the specified indices.

Parameters:

start - inclusive

stop - exclusive

replaceSubArray

public void replaceSubArray(java.lang.Object array,
                            int atIndex)

Allows an array type to overwrite a segment of the array. Will expand the array if (atIndex + 1) + ofArrayType's length is greater than the current length.

AbstractList subclasses should update their modCount after calling this method.

Parameters:

array -

atIndex -

replaceSubArray

public void replaceSubArray(int thisStart,
                            int thisStop,
                            java.lang.Object srcArray,
                            int srcStart,
                            int srcStop)

Replace a range of this array with another subarray.

Parameters:

thisStart - the start index (inclusive) of the subarray in this array to be replaced

thisStop - the stop index (exclusive) of the subarray in this array to be replaced

srcArray - the source array from which to copy

srcStart - the start index (inclusive) of the replacement subarray

srcStop - the stop index (exclusive) of the replacement subarray

setSize

public void setSize(int count)

Sets the number of values currently present in the array. If the new size is greater than the current size, the added values are initialized to the default values. If the new size is less than the current size, all values dropped from the array are discarded.

AbstractList subclasses should update their modCount after calling this method.

Parameters:

count - number of values to be set

getSize

public int getSize()

Get the number of values currently present in the array.

Returns:

count of values present

toString

public java.lang.String toString()

Provides a default comma-delimited representation of array.

See Also:

Object.toString()

getModCountIncr

public int getModCountIncr()

Returns the modification count increment, which is used by AbstractList subclasses to adjust modCount AbstractList uses it's modCount field to invalidate concurrent operations (like iteration) that should fail if the underlying array changes structurally during the operation.

Returns:

the modification count increment (0 if no change, 1 if changed)