net.sf.saxon.value

Class NumericValue

java.lang.Object

net.sf.saxon.om.AbstractItem

net.sf.saxon.value.AtomicValue

net.sf.saxon.value.NumericValue

All Implemented Interfaces:

Comparable, Iterable<AtomicValue>, PullEvent, AtomicMatchKey, AtomicSequence, GroundedValue, IdentityComparable, Item, Sequence, ConversionResult

Direct Known Subclasses:

DecimalValue, DoubleValue, FloatValue, IntegerValue

public abstract class NumericValue
extends AtomicValue
implements Comparable, AtomicMatchKey

NumericValue is an abstract superclass for IntegerValue, DecimalValue, FloatValue, and DoubleValue

Field Summary

Fields inherited from class net.sf.saxon.value.AtomicValue

NaN_MATCH_KEY, typeLabel

Constructor Summary

Constructors

Constructor and Description
NumericValue()

Method Summary

Methods

Modifier and Type	Method and Description
abstract NumericValue	abs() Get the absolute value as defined by the XPath abs() function
abstract NumericValue	ceiling() Implement the XPath ceiling() function
abstract int	compareTo(long other) Compare the value to a long
int	compareTo(Object other) Compare the value to another numeric value
boolean	equals(Object other) The equals() function compares numeric equality among integers, decimals, floats, doubles, and their subtypes
abstract NumericValue	floor() Implement the XPath floor() function
abstract BigDecimal	getDecimalValue() Get the numeric value converted to a decimal
abstract double	getDoubleValue() Get the numeric value as a double
abstract float	getFloatValue() Get the numeric value converted to a float
AtomicMatchKey	getXPathComparable(boolean ordered, StringCollator collator, int implicitTimezone) Get a Comparable value that implements the XPath ordering comparison semantics for this value.
abstract int	hashCode() hashCode() must be the same for two values that are equal.
static boolean	isInteger(AtomicValue value) Test whether a value is an integer (an instance of a subtype of xs:integer)
boolean	isNegativeZero() Ask whether this value is negative zero
abstract boolean	isWholeNumber() Ask whether the value is a whole number, that is, whether it compares equal to some integer
abstract long	longValue() Return the numeric value as a Java long.
abstract NumericValue	negate() Change the sign of the number
static NumericValue	parseNumber(String in) Get a numeric value by parsing a string; the type of numeric value depends on the lexical form of the string, following the rules for XPath numeric literals.
abstract NumericValue	round(int scale) Implement the XPath round() function
abstract NumericValue	roundHalfToEven(int scale) Implement the XPath 2.0 round-half-to-even() function
abstract int	signum() Ask whether the value is negative, zero, or positive
String	toString() Produce a string representation of the value

Methods inherited from class net.sf.saxon.value.AtomicValue

asAtomic, checkPermittedContents, copyAsSubType, effectiveBooleanValue, getCanonicalLexicalRepresentation, getCardinality, getComponent, getItemType, getPrimitiveStringValue, getPrimitiveType, getSchemaComparable, getStringValue, getStringValueCS, head, identityHashCode, isIdentical, isIdentical, isNaN, itemAt, iterate, iterator, process, setTypeLabel

Methods inherited from class net.sf.saxon.om.AbstractItem

getLength, reduce, subsequence

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface net.sf.saxon.expr.sort.AtomicMatchKey

asAtomic

Methods inherited from interface net.sf.saxon.om.AtomicSequence

getLength

Methods inherited from interface net.sf.saxon.om.GroundedValue

reduce, subsequence

Constructor Detail

NumericValue

public NumericValue()

Method Detail

parseNumber

public static NumericValue parseNumber(String in)

Get a numeric value by parsing a string; the type of numeric value depends on the lexical form of the string, following the rules for XPath numeric literals.

Parameters:

in - the input string

Returns:

a NumericValue representing the value of the string. Returns Double.NaN if the value cannot be parsed as a string.

getDoubleValue

public abstract double getDoubleValue()

Get the numeric value as a double

Returns:

A double representing this numeric value; NaN if it cannot be converted

getFloatValue

public abstract float getFloatValue()

Get the numeric value converted to a float

Returns:

a float representing this numeric value; NaN if it cannot be converted

getDecimalValue

public abstract BigDecimal getDecimalValue()
                                    throws XPathException

Get the numeric value converted to a decimal

Returns:

a decimal representing this numeric value;

Throws:

XPathException - if the value cannot be converted, for example if it is NaN or infinite

isInteger

public static boolean isInteger(AtomicValue value)

Test whether a value is an integer (an instance of a subtype of xs:integer)

Parameters:

value - the value being tested

Returns:

true if the value is an instance of xs:integer or a type derived therefrom

longValue

public abstract long longValue()
                        throws XPathException

Return the numeric value as a Java long.

Returns:

the numeric value as a Java long. This performs truncation towards zero.

Throws:

XPathException - if the value cannot be converted

negate

public abstract NumericValue negate()

Change the sign of the number

Returns:

a value, of the same type as the original, with its sign inverted

floor

public abstract NumericValue floor()

Implement the XPath floor() function

Returns:

a value, of the same type as that supplied, rounded towards minus infinity

ceiling

public abstract NumericValue ceiling()

Implement the XPath ceiling() function

Returns:

a value, of the same type as that supplied, rounded towards plus infinity

round

public abstract NumericValue round(int scale)

Implement the XPath round() function

Parameters:

scale - the number of decimal places required in the result (supply 0 for rounding to an integer)

Returns:

a value, of the same type as that supplied, rounded towards the nearest whole number (0.5 rounded up)

roundHalfToEven

public abstract NumericValue roundHalfToEven(int scale)

Implement the XPath 2.0 round-half-to-even() function

Parameters:

scale - the decimal position for rounding: e.g. 2 rounds to a multiple of 0.01, while -2 rounds to a multiple of 100

Returns:

a value, of the same type as the original, rounded towards the nearest multiple of 10**(-scale), with rounding towards the nearest even number if two values are equally near

signum

public abstract int signum()

Ask whether the value is negative, zero, or positive

Returns:

-1 if negative, 0 if zero (including negative zero) or NaN, +1 if positive

isNegativeZero

public boolean isNegativeZero()

Ask whether this value is negative zero

Returns:

true if this value is float or double negative zero

isWholeNumber

public abstract boolean isWholeNumber()

Ask whether the value is a whole number, that is, whether it compares equal to some integer

Returns:

true if the value is a whole number

abs

public abstract NumericValue abs()

Get the absolute value as defined by the XPath abs() function

Returns:

the absolute value

Since:

9.2

getXPathComparable

public final AtomicMatchKey getXPathComparable(boolean ordered,
                                StringCollator collator,
                                int implicitTimezone)

Get a Comparable value that implements the XPath ordering comparison semantics for this value. Returns null if the value is not comparable according to XPath rules. The implementation for all kinds of NumericValue returns the value itself.

Specified by:

getXPathComparable in class AtomicValue

Parameters:

ordered - true if an ordered comparison is required. In this case the result is null if the type is unordered; in other cases the returned value will be a Comparable.

collator - the collation to be used when comparing strings

implicitTimezone - the implicit timezone in the dynamic context, used when comparing dates/times with and without timezone

Returns:

a collation key that implements the comparison semantics

compareTo

public int compareTo(Object other)

Compare the value to another numeric value

Specified by:

compareTo in interface Comparable

Parameters:

other - The other numeric value

Returns:

-1 if this one is the lower, 0 if they are numerically equal, +1 if this one is the higher, or if either value is NaN. Where NaN values are involved, they should be handled by the caller before invoking this method.

Throws:

ClassCastException - if the other value is not a NumericValue (the parameter is declared as Object to satisfy the Comparable interface)

compareTo

public abstract int compareTo(long other)

Compare the value to a long

Parameters:

other - the value to be compared with

Returns:

-1 if this is less, 0 if this is equal, +1 if this is greater or if this is NaN

equals

public final boolean equals(Object other)

The equals() function compares numeric equality among integers, decimals, floats, doubles, and their subtypes

Specified by:

equals in class AtomicValue

Parameters:

other - the value to be compared with this one

Returns:

true if the two values are numerically equal

hashCode

public abstract int hashCode()

hashCode() must be the same for two values that are equal. One way to ensure this is to convert the value to a double, and take the hashCode of the double. But this is expensive in the common case where we are comparing integers. So we adopt the rule: for values that are in the range of a Java Integer, we use the int value as the hashcode. For values outside that range, we convert to a double and take the hashCode of the double. This method needs to have a compatible implementation in each subclass.

Overrides:

hashCode in class Object

Returns:

the hash code of the numeric value

toString

public String toString()

Produce a string representation of the value

Overrides:

toString in class AtomicValue

Returns:

The result of casting the number to a string