org.graalvm.shadowed.com.ibm.icu.impl.number

Class RoundingUtils

java.lang.Object

org.graalvm.shadowed.com.ibm.icu.impl.number.RoundingUtils

public class RoundingUtils
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
static MathContext	DEFAULT_MATH_CONTEXT_34_DIGITS The default MathContext, 34-digit version.
static MathContext	DEFAULT_MATH_CONTEXT_UNLIMITED The default MathContext, unlimited-precision version.
static RoundingMode	DEFAULT_ROUNDING_MODE The default rounding mode.
static int	MAX_INT_FRAC_SIG The maximum number of fraction places, integer numerals, or significant digits.
static int	SECTION_LOWER
static int	SECTION_MIDPOINT
static int	SECTION_UPPER

Constructor Summary

Constructors

Constructor and Description
RoundingUtils()

Method Summary

Modifier and Type	Method and Description
static MathContext	getMathContextOr34Digits(DecimalFormatProperties properties) Gets the user-specified math context out of the property bag.
static MathContext	getMathContextOrUnlimited(DecimalFormatProperties properties) Gets the user-specified math context out of the property bag.
static StandardPlural	getPluralSafe(Precision rounder, PluralRules rules, DecimalQuantity dq) Computes the plural form after copying the number and applying rounding rules.
static boolean	getRoundingDirection(boolean isEven, boolean isNegative, int section, int roundingMode, Object reference) Converts a rounding mode and metadata about the quantity being rounded to a boolean determining whether the value should be rounded toward infinity or toward zero.
static MathContext	mathContextUnlimited(RoundingMode roundingMode) Gets a MathContext with unlimited precision and the specified RoundingMode.
static boolean	roundsAtMidpoint(int roundingMode) Gets whether the given rounding mode's rounding boundary is at the midpoint.
static Scale	scaleFromProperties(DecimalFormatProperties properties)

Methods inherited from class java.lang.Object

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

Field Detail

SECTION_LOWER

public static final int SECTION_LOWER

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Constant Field Values

SECTION_MIDPOINT

public static final int SECTION_MIDPOINT

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Constant Field Values

SECTION_UPPER

public static final int SECTION_UPPER

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Constant Field Values

DEFAULT_ROUNDING_MODE

public static final RoundingMode DEFAULT_ROUNDING_MODE

The default rounding mode.

MAX_INT_FRAC_SIG

public static final int MAX_INT_FRAC_SIG

The maximum number of fraction places, integer numerals, or significant digits. TODO: This does not feel like the best home for this value.

See Also:

Constant Field Values

DEFAULT_MATH_CONTEXT_UNLIMITED

public static final MathContext DEFAULT_MATH_CONTEXT_UNLIMITED

The default MathContext, unlimited-precision version.

DEFAULT_MATH_CONTEXT_34_DIGITS

public static final MathContext DEFAULT_MATH_CONTEXT_34_DIGITS

The default MathContext, 34-digit version.

Constructor Detail

RoundingUtils

public RoundingUtils()

Method Detail

getRoundingDirection

public static boolean getRoundingDirection(boolean isEven,
                                           boolean isNegative,
                                           int section,
                                           int roundingMode,
                                           Object reference)

Converts a rounding mode and metadata about the quantity being rounded to a boolean determining whether the value should be rounded toward infinity or toward zero.

The parameters are of type int because benchmarks on an x86-64 processor against OpenJDK showed that ints were demonstrably faster than enums in switch statements.

Parameters:

isEven - Whether the digit immediately before the rounding magnitude is even.

isNegative - Whether the quantity is negative.

section - Whether the part of the quantity to the right of the rounding magnitude is exactly halfway between two digits, whether it is in the lower part (closer to zero), or whether it is in the upper part (closer to infinity). See RoundingUtils.SECTION_LOWER, RoundingUtils.SECTION_MIDPOINT, and RoundingUtils.SECTION_UPPER.

roundingMode - The integer version of the RoundingMode, which you can get via Enum.ordinal.

reference - A reference object to be used when throwing an ArithmeticException.

Returns:

true if the number should be rounded toward zero; false if it should be rounded toward infinity.

roundsAtMidpoint

public static boolean roundsAtMidpoint(int roundingMode)

Gets whether the given rounding mode's rounding boundary is at the midpoint. The rounding boundary is the point at which a number switches from being rounded down to being rounded up. For example, with rounding mode HALF_EVEN, HALF_UP, or HALF_DOWN, the rounding boundary is at the midpoint, and this function would return true. However, for UP, DOWN, CEILING, and FLOOR, the rounding boundary is at the "edge", and this function would return false.

Parameters:

roundingMode - The integer version of the RoundingMode.

Returns:

true if rounding mode is HALF_EVEN, HALF_UP, or HALF_DOWN; false otherwise.

getMathContextOrUnlimited

public static MathContext getMathContextOrUnlimited(DecimalFormatProperties properties)

Gets the user-specified math context out of the property bag. If there is none, falls back to a math context with unlimited precision and the user-specified rounding mode, which defaults to HALF_EVEN (the IEEE 754R default).

Parameters:

properties - The property bag.

Returns:

A MathContext. Never null.

getMathContextOr34Digits

public static MathContext getMathContextOr34Digits(DecimalFormatProperties properties)

Gets the user-specified math context out of the property bag. If there is none, falls back to a math context with 34 digits of precision (the 128-bit IEEE 754R default) and the user-specified rounding mode, which defaults to HALF_EVEN (the IEEE 754R default).

Parameters:

properties - The property bag.

Returns:

A MathContext. Never null.

mathContextUnlimited

public static MathContext mathContextUnlimited(RoundingMode roundingMode)

Gets a MathContext with unlimited precision and the specified RoundingMode. Equivalent to "new MathContext(0, roundingMode)", but pulls from a singleton to prevent object thrashing.

Parameters:

roundingMode - The RoundingMode to use.

Returns:

The corresponding MathContext.

scaleFromProperties

public static Scale scaleFromProperties(DecimalFormatProperties properties)

getPluralSafe

public static StandardPlural getPluralSafe(Precision rounder,
                                           PluralRules rules,
                                           DecimalQuantity dq)

Computes the plural form after copying the number and applying rounding rules.