com.yahoo.text

Class DoubleFormatter

java.lang.Object

com.yahoo.text.DoubleFormatter

@Beta
public final class DoubleFormatter
extends Object

Utility class to format a double into a String.

This is intended as a lower-cost replacement for the standard String.valueOf(double) since that method will cause lock contention if it's used too often.

Note that this implementation won't always produce the same results as java.lang.* formatting.

Also, this implementation is very poorly tested at the moment, so it should be used carefully, only in cases where you know the input will be well-defined and you don't need full precision.

Author:

arnej27959

Field Summary

Fields

Modifier and Type	Field and Description
private static char[]	charForDigit
private static double[]	d_tenthPowers
static char[]	DOT_ZERO
static char[]	DOUBLE_ZERO
static char[]	DOUBLE_ZERO0
static char[]	DOUBLE_ZERO2
private static int	DoubleExpBias
private static long	DoubleExpMask
private static int	DoubleExpShift
private static long	DoubleFractMask
private static long	DoubleSignMask
static char[]	INFINITY
(package private) static long[]	l_tenthPowers
static char[]	NaN
static char[]	NEGATIVE_INFINITY
static char[]	POSITIVE_INFINITY
static char[][]	ZEROS

Constructor Summary

Constructors

Constructor and Description
DoubleFormatter()

Method Summary

Modifier and Type	Method and Description
static void	append(StringBuilder s, double d)
static void	append(StringBuilder s, int i)
private static void	appendFractDigits(StringBuilder s, long i, int decimalOffset)
static StringBuilder	fmt(StringBuilder target, double v)
static long	getNthDigit(long l, int n)
private static int	magnitude(double d)
static String	stringValue(double v)
private static long	tenthPower(long i) Assumes i is positive.
private static void	tooSmall(StringBuilder target, long mantissa, int exponent)

Methods inherited from class java.lang.Object

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

Field Detail

INFINITY

public static final char[] INFINITY

NaN

public static final char[] NaN

ZEROS

public static final char[][] ZEROS

charForDigit

private static final char[] charForDigit

DoubleSignMask

private static final long DoubleSignMask

See Also:

Constant Field Values

DoubleExpMask

private static final long DoubleExpMask

See Also:

Constant Field Values

DoubleFractMask

private static final long DoubleFractMask

See Also:

Constant Field Values

DoubleExpShift

private static final int DoubleExpShift

See Also:

Constant Field Values

DoubleExpBias

private static final int DoubleExpBias

See Also:

Constant Field Values

d_tenthPowers

private static final double[] d_tenthPowers

l_tenthPowers

static long[] l_tenthPowers

NEGATIVE_INFINITY

public static final char[] NEGATIVE_INFINITY

POSITIVE_INFINITY

public static final char[] POSITIVE_INFINITY

DOUBLE_ZERO

public static final char[] DOUBLE_ZERO

DOUBLE_ZERO2

public static final char[] DOUBLE_ZERO2

DOUBLE_ZERO0

public static final char[] DOUBLE_ZERO0

DOT_ZERO

public static final char[] DOT_ZERO

Constructor Detail

DoubleFormatter

public DoubleFormatter()

Method Detail

tooSmall

private static void tooSmall(StringBuilder target,
                             long mantissa,
                             int exponent)

fmt

public static StringBuilder fmt(StringBuilder target,
                                double v)

stringValue

public static String stringValue(double v)

tenthPower

private static long tenthPower(long i)

Assumes i is positive. Returns the magnitude of i in base 10.

magnitude

private static int magnitude(double d)

getNthDigit

public static long getNthDigit(long l,
                               int n)

append

public static void append(StringBuilder s,
                          double d)

append

public static void append(StringBuilder s,
                          int i)

appendFractDigits

private static void appendFractDigits(StringBuilder s,
                                      long i,
                                      int decimalOffset)