DPJRuntime
Class DPJArrayInt<region R>

java.lang.Object
  DPJRuntime.DPJArrayInt<region R>

Type Parameters:

R - The region of a cell of this DPJArrayInt

public class DPJArrayInt<region R>
extends java.lang.Object

The DPJArray class, specialized to int.

The DPJArrayInt class wraps and provides a "view" of an ordinary Java array of int. In addition to array-element access, the DPJArrayInt class supports the creation of a subarray, which is a contiguous slice of the original array. The subarray itself is a new DPJArrayInt object. Both the original DPJArrayInt and the subarray wrap the same underlying Java array.

A DPJArrayInt stores a start position (indexed into the underlying array) and a length. Accesses to the DPJArrayInt are translated into accesses into the underlying array, offset by the start position. They are bounds-checked against the length of the DPJArrayInt. For example:

 // Create a Java array a of 10 int
 int[] a = new int[10];
 // Wrap a in a DPJArrayInt
 DPJArrayInt A = new DPJArrayInt(a);
 // Create a subarray of A
 DPJArrayInt B = A.subarray(5,2);
 // Store value 1 into position 5 of a
 B.put(0,1);
 // Error:  Out of bounds
 B.put(3,5);
 

Field Summary

int	length The number of elements in the DPJArrayInt
int	start The start index for indexing into the underlying array

Constructor Summary

DPJArrayInt(int length)
Creates a DPJArrayInt of the specified length, wrapping a freshly created Java array with the same length.

DPJArrayInt(int[]<R> elts)
Creates a DPJArrayInt that wraps the given Java array.

Method Summary

int	get(int idx) Returns the value stored at index idx of this DPJArrayInt.
void	put(int idx, int val) Replaces the value at index idx of this DPJArrayInt with value val.
DPJArrayInt<R>	subarray(int start, int length) Creates and returns a new DPJArrayInt starting at index start with length length that wraps the same underlying array as this DPJArrayInt.
void	swap(int i, int j) Swaps the values at indices i and j of this DPJArrayInt.
int[]<R>	toArray() Returns the underlying Java array for this DPJArrayInt.
java.lang.String	toString() Returns a string representation of this DPJArrayInt.

Methods inherited from class java.lang.Object

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

Field Detail

start

public final int start

The start index for indexing into the underlying array

length

public final int length

The number of elements in the DPJArrayInt

Constructor Detail

DPJArrayInt

public DPJArrayInt(int length)
            pure

Creates a DPJArrayInt of the specified length, wrapping a freshly created Java array with the same length.

Parameters:

length - The length of the DPJArrayInt

DPJArrayInt

public DPJArrayInt(int[]<R> elts)
            pure

Creates a DPJArrayInt that wraps the given Java array.

Parameters:

elts - The Java array to wrap

Method Detail

get

public int get(int idx)
        reads  R

Returns the value stored at index idx of this DPJArrayInt.

Throws ArrayIndexOutOfBoundsException if idx is outside the bounds of this DPJArrayInt (even if it is in bounds for the underlying array).

Parameters:

idx - Index of value to return

return - Value stored at idx

put

public void put(int idx,
                int val)
         writes R

Replaces the value at index idx of this DPJArrayInt with value val.

Throws ArrayIndexOutOfBoundsException if idx is outside the bounds of this DPJArrayInt (even if it is in bounds for the underlying array).

Parameters:

idx - Index of value to replace

val - New value

subarray

public DPJArrayInt<R> subarray(int start,
                               int length)
                        pure

Creates and returns a new DPJArrayInt starting at index start with length length that wraps the same underlying array as this DPJArrayInt. Index i of the new DPJArrayInt refers to the same cell of the underlying array as index start+i of this.

Throws ArrayIndexOutOfBoundsException if the interval start,start+length-1] is not in bounds for this DPJArrayInt.

Parameters:

start - Start index for the subarray

length - Length of the subarray

Returns:

Subarray of this DPJArrayInt defined by start and length

toArray

public int[]<R> toArray()
                       pure

Returns the underlying Java array for this DPJArrayInt.

Returns:

The underlying Java array

toString

public java.lang.String toString()
                          reads  R

Returns a string representation of this DPJArrayInt.

Overrides:

toString in class java.lang.Object

Returns:

A string representation

swap

public void swap(int i,
                 int j)
          writes R

Swaps the values at indices i and j of this DPJArrayInt.

Parameters:

i - First index to swap

j - Second index to swap