net.sf.saxon.value

Class NumericValue

java.lang.Object

net.sf.saxon.value.AtomicValue

net.sf.saxon.value.NumericValue

All Implemented Interfaces:

java.lang.Comparable<XPathComparable>, java.lang.Iterable<AtomicValue>, AtomicMatchKey, XPathComparable, AtomicSequence, GroundedValue, IdentityComparable, Item, Sequence, ConversionResult, ContextFreeAtomicValue

Direct Known Subclasses:

DecimalValue, DoubleValue, FloatValue

public abstract class NumericValue
extends AtomicValue
implements XPathComparable, AtomicMatchKey, ContextFreeAtomicValue

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

Field Summary

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

typeLabel

Constructor Summary

Constructors

Constructor and Description
NumericValue()

Method Summary

Modifier and Type	Method and Description
abstract NumericValue	abs() Get the absolute value as defined by the XPath abs() function
abstract int	asSubscript() Test whether a number is a possible subscript into a sequence, that is, a whole number greater than zero and less than 2^31
abstract NumericValue	ceiling() Implement the XPath ceiling() function
abstract int	compareTo(long other) Compare the value to a long
int	compareTo(XPathComparable other) Compare the value to another numeric value
abstract boolean	effectiveBooleanValue() Get the effective boolean value of the value.
boolean	equals(java.lang.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 java.math.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
XPathComparable	getXPathComparable() Get an XPathComparable object that supports the semantics of context-free eq and lt comparisons between atomic values.
XPathComparable	getXPathComparable(StringCollator collator, int implicitTimezone) Get an object value that implements the XPath equality and ordering comparison semantics for this value.
AtomicMatchKey	getXPathMatchKey(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(java.lang.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
java.lang.String	show() Produce a string representation of the value
abstract int	signum() Ask whether the value is negative, zero, or positive

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

asAtomic, asMapKey, atomize, checkPermittedContents, checkValidInJavascript, copyAsSubType, getCanonicalLexicalRepresentation, getCardinality, getComponent, getGenre, getItemType, getLength, getPrimitiveStringValue, getPrimitiveType, getUnicodeStringValue, getUType, head, identityHashCode, isIdentical, isIdentical, isNaN, isUntypedAtomic, itemAt, iterate, iterator, setTypeLabel, toShortString, toString

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.Item

getStringValue, isStreamed, reduce, subsequence

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

asIterable, concatenate, containsNode, materialize

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

makeRepeatable

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

NumericValue

public NumericValue()

Method Detail

parseNumber

public static NumericValue parseNumber(java.lang.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 java.math.BigDecimal getDecimalValue()
                                              throws ValidationException

Get the numeric value converted to a decimal

Returns:

a decimal representing this numeric value;

Throws:

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

effectiveBooleanValue

public abstract boolean effectiveBooleanValue()

Get the effective boolean value of the value. This override of this method throws no exceptions.

Specified by:

effectiveBooleanValue in interface GroundedValue

Overrides:

effectiveBooleanValue in class AtomicValue

Returns:

true, unless the value is boolean false, numeric zero, or zero-length string

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

asSubscript

public abstract int asSubscript()

Test whether a number is a possible subscript into a sequence, that is, a whole number greater than zero and less than 2^31

Returns:

the number as an int if it is a possible subscript, or -1 otherwise

abs

public abstract NumericValue abs()

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

Returns:

the absolute value

Since:

9.2

getXPathMatchKey

public final AtomicMatchKey getXPathMatchKey(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:

getXPathMatchKey in class AtomicValue

Parameters:

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

getXPathComparable

public XPathComparable getXPathComparable(StringCollator collator,
                                          int implicitTimezone)
                                   throws NoDynamicContextException

Description copied from class: AtomicValue

Get an object value that implements the XPath equality and ordering comparison semantics for this value. A collation is supplied for comparing strings, and an implicit timezone for comparing date/time values that have no saved timezone. An atomic value may return itself as the result, provided that its ordering rules are independent of the collation and timezone, and provided that it implements the XPathComparable interface: which means that its compareTo, equals, and hashCode methods must be compatible with the rules for XPath value comparisons.

Specified by:

getXPathComparable in class AtomicValue

Parameters:

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:

an Object that implements the XPath value comparison semantics with respect to this atomic value. For an atomic type that is not ordered (according to XPath rules), return null.

Throws:

NoDynamicContextException - if the supplied implicit timezone is "NO_TIMEZONE" (meaning unknown), and the implicit timezone is actually required because the value in question is a date/time value with no timezone. This can cause a failure to evaluate expressions statically (because the implicit timezone is not known statically), and it will then be caught, meaning that the expression has to be evaluated dynamically.

getXPathComparable

public XPathComparable getXPathComparable()

Description copied from interface: ContextFreeAtomicValue

Get an XPathComparable object that supports the semantics of context-free eq and lt comparisons between atomic values. Note that in many cases the returned XPathComparable will be the AtomicValue itself; however because of the constraints of the generic Comparable interface, this cannot be assumed.

Specified by:

getXPathComparable in interface ContextFreeAtomicValue

Returns:

an XPathComparable that can be used in comparisons with other atomic values.

compareTo

public int compareTo(XPathComparable other)

Compare the value to another numeric value

Specified by:

compareTo in interface java.lang.Comparable<XPathComparable>

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:

java.lang.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(java.lang.Object other)

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

Overrides:

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 AtomicValue

Returns:

the hash code of the numeric value

show

public java.lang.String show()

Produce a string representation of the value

Overrides:

show in class AtomicValue

Returns:

The result of casting the number to a string