org.python.core

Class AbstractArray

public abstract class AbstractArray extends Object implements 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):

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

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(int size)
Use when the subclass has a preexisting array.
AbstractArray(Class type)
Creates the managed array with a default size of 10.
AbstractArray(Class type, int[] dimensions)
Construtor for multi-dimensional array types.
AbstractArray(Class type, int size)
Creates the managed array with the specified size.
Method Summary
voidappendArray(Object ofArrayType)
Appends the supplied array, which must be an array of the same type as this, to the end of this.
voidclear()
Set the array to the empty state, clearing all the data out and nulling objects (or "zero-ing" primitives).
ObjectcopyArray()
Constructs and returns a simple array containing the same data as held in this growable array.
intgetModCountIncr()
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.
intgetSize()
Get the number of values currently present in the array.
voidremove(int index)
Remove a value from the array.
voidremove(int start, int stop)
Removes a range from the array at the specified indices.
voidreplaceSubArray(Object array, int atIndex)
Allows an array type to overwrite a segment of the array.
voidreplaceSubArray(int thisStart, int thisStop, Object srcArray, int srcStart, int srcStop)
Replace a range of this array with another subarray.
voidsetSize(int count)
Sets the number of values currently present in the array.
StringtoString()
Provides a default comma-delimited representation of array.

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(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(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(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(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 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.

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)

getSize

public int getSize()
Get the number of values currently present in the array.

Returns: count of values present

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(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, 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

toString

public String toString()
Provides a default comma-delimited representation of array.

See Also: java.lang.Object#toString()