frysk.gui.common
Class UBigInteger

java.lang.Object
  frysk.gui.common.UBigInteger

public class UBigInteger
extends Object

Some utility functions for treating BigIntegers as unsigned integers.

Constructor Summary

UBigInteger()

Method Summary

private static BigInteger	makeMask(int integerLength)
static BigInteger	mask(BigInteger val, int integerLength) Mask off the lower bits of a BigInteger, replacing the upper bits with zeros (obviously).
static BigInteger	signExtend(BigInteger val, int integerLength) Treat the MSB of an unsigned integer stored in a BigInteger as a sign bit and return a positive or negative BigInteger as appropriate.
static String	toString(BigInteger val, int integerLength, int radix) Print the string representation of an unsigned integer.

Methods inherited from class java.lang.Object

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

Constructor Detail

UBigInteger

public UBigInteger()

Method Detail

makeMask

private static BigInteger makeMask(int integerLength)

mask

public static BigInteger mask(BigInteger val,
                              int integerLength)

Mask off the lower bits of a BigInteger, replacing the upper bits with zeros (obviously).

Parameters:

val - BigInteger value

integerLength - length of bits to preserve

Returns:

masked value.

toString

public static String toString(BigInteger val,
                              int integerLength,
                              int radix)

Print the string representation of an unsigned integer.

Parameters:

val - the BigInteger holding the unsigned integer

integerLength - length of unsigned integer

radix - of output

Returns:

string represntation

signExtend

public static BigInteger signExtend(BigInteger val,
                                    int integerLength)

Treat the MSB of an unsigned integer stored in a BigInteger as a sign bit and return a positive or negative BigInteger as appropriate.

Parameters:

val - the BigInteger value

integerLength - length of unsigned integer, or 1 plus bit position of sign bit.

Returns:

new integer with proper sign.