net.sf.saxon.value

Class DoubleValue

java.lang.Object

net.sf.saxon.om.AbstractItem

net.sf.saxon.value.AtomicValue

net.sf.saxon.value.NumericValue

net.sf.saxon.value.DoubleValue

All Implemented Interfaces:

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

public final class DoubleValue
extends NumericValue

A numeric (double precision floating point) value

Field Summary

Fields

Modifier and Type	Field and Description
static DoubleValue	NaN
static DoubleValue	NEGATIVE_ZERO
static DoubleValue	ONE
static DoubleValue	ZERO

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

NaN_MATCH_KEY, typeLabel

Constructor Summary

Constructors

Constructor and Description
DoubleValue(double value) Constructor supplying a double
DoubleValue(double value, AtomicType type) Constructor supplying a double and an AtomicType, for creating a value that belongs to a user-defined subtype of xs:double.

Method Summary

Methods

Modifier and Type	Method and Description
NumericValue	abs() Get the absolute value as defined by the XPath abs() function
AtomicMatchKey	asMapKey() Get a value whose equals() method follows the "same key" rules for comparing the keys of a map.
NumericValue	ceiling() Implement the XPath ceiling() function
int	compareTo(long other) Compare the value to a long.
AtomicValue	copyAsSubType(AtomicType typeLabel) Create a copy of this atomic value, with a different type label
static CharSequence	doubleToString(double value) Internal method used for conversion of a double to a string
boolean	effectiveBooleanValue() Get the effective boolean value
NumericValue	floor() Implement the XPath floor() function
CharSequence	getCanonicalLexicalRepresentation() Get the canonical lexical representation as defined in XML Schema.
BigDecimal	getDecimalValue() Get the numeric value converted to a decimal
double	getDoubleValue() Return this numeric value as a double
float	getFloatValue() Get the numeric value converted to a float
CharSequence	getPrimitiveStringValue() Convert the double to a string according to the XPath 2.0 rules
BuiltInAtomicType	getPrimitiveType() Determine the primitive type of the value.
Comparable	getSchemaComparable() Get an object that implements XML Schema comparison semantics
int	hashCode() Get the hashCode.
boolean	isIdentical(AtomicValue v) Determine whether two atomic values are identical, as determined by XML Schema rules.
boolean	isNaN() Test whether the value is the double/float value NaN
boolean	isNegativeZero() Ask whether this value is negative zero
boolean	isWholeNumber() Determine whether the value is a whole number, that is, whether it compares equal to some integer
long	longValue() Return the numeric value as a Java long.
static DoubleValue	makeDoubleValue(double value) Static factory method (for convenience in compiled bytecode)
NumericValue	negate() Negate the value
NumericValue	round(int scale) Implement the XPath round() function
NumericValue	roundHalfToEven(int scale) Implement the XPath round-to-half-even() function
int	signum() Determine whether the value is negative, zero, or positive

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

compareTo, equals, getXPathComparable, isInteger, parseNumber, toString

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

asAtomic, atomize, checkPermittedContents, getCardinality, getComponent, getItemType, getStringValue, getStringValueCS, getUType, head, identityHashCode, isIdentical, 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

Field Detail

ZERO

public static final DoubleValue ZERO

NEGATIVE_ZERO

public static final DoubleValue NEGATIVE_ZERO

ONE

public static final DoubleValue ONE

NaN

public static final DoubleValue NaN

Constructor Detail

DoubleValue

public DoubleValue(double value)

Constructor supplying a double

Parameters:

value - the value of the NumericValue

DoubleValue

public DoubleValue(double value,
           AtomicType type)

Constructor supplying a double and an AtomicType, for creating a value that belongs to a user-defined subtype of xs:double. It is the caller's responsibility to ensure that the supplied value conforms to the supplied type.

Parameters:

value - the value of the NumericValue

type - the type of the value. This must be a subtype of xs:double, and the value must conform to this type. The methosd does not check these conditions.

Method Detail

makeDoubleValue

public static DoubleValue makeDoubleValue(double value)

Static factory method (for convenience in compiled bytecode)

Parameters:

value - the value of the double

Returns:

a new DoubleValue

copyAsSubType

public AtomicValue copyAsSubType(AtomicType typeLabel)

Create a copy of this atomic value, with a different type label

Specified by:

copyAsSubType in class AtomicValue

Parameters:

typeLabel - the type label of the new copy. The caller is responsible for checking that the value actually conforms to this type.

Returns:

the copied value

getPrimitiveType

public BuiltInAtomicType getPrimitiveType()

Determine the primitive type of the value. This delivers the same answer as getItemType().getPrimitiveItemType(). The primitive types are the 19 primitive types of XML Schema, plus xs:integer, xs:dayTimeDuration and xs:yearMonthDuration, and xs:untypedAtomic. For external objects, the result is AnyAtomicType.

Specified by:

getPrimitiveType in class AtomicValue

Returns:

the primitive type

getDoubleValue

public double getDoubleValue()

Return this numeric value as a double

Specified by:

getDoubleValue in class NumericValue

Returns:

the value as a double

getFloatValue

public float getFloatValue()

Get the numeric value converted to a float

Specified by:

getFloatValue in class NumericValue

Returns:

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

getDecimalValue

public BigDecimal getDecimalValue()
                           throws XPathException

Get the numeric value converted to a decimal

Specified by:

getDecimalValue in class NumericValue

Returns:

a decimal representing this numeric value;

Throws:

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

longValue

public long longValue()
               throws XPathException

Return the numeric value as a Java long.

Specified by:

longValue in class NumericValue

Returns:

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

Throws:

XPathException - if the value cannot be converted

hashCode

public int hashCode()

Get the hashCode. This must conform to the rules for other NumericValue hashcodes

Specified by:

hashCode in class NumericValue

Returns:

the hash code of the numeric value

See Also:

NumericValue.hashCode()

isNaN

public boolean isNaN()

Test whether the value is the double/float value NaN

Overrides:

isNaN in class AtomicValue

Returns:

true if the value is float NaN or double NaN or precisionDecimal NaN; otherwise false

effectiveBooleanValue

public boolean effectiveBooleanValue()

Get the effective boolean value

Specified by:

effectiveBooleanValue in interface GroundedValue

Overrides:

effectiveBooleanValue in class AtomicValue

Returns:

the effective boolean value (true unless the value is zero or NaN)

getPrimitiveStringValue

public CharSequence getPrimitiveStringValue()

Convert the double to a string according to the XPath 2.0 rules

Specified by:

getPrimitiveStringValue in class AtomicValue

Returns:

the string value

getCanonicalLexicalRepresentation

public CharSequence getCanonicalLexicalRepresentation()

Get the canonical lexical representation as defined in XML Schema. This is not always the same as the result of casting to a string according to the XPath rules. For xs:double, the canonical representation always uses exponential notation.

Specified by:

getCanonicalLexicalRepresentation in interface AtomicSequence

Overrides:

getCanonicalLexicalRepresentation in class AtomicValue

Returns:

the canonical lexical representation if defined in XML Schema; otherwise, the result of casting to string according to the XPath 2.0 rules

doubleToString

public static CharSequence doubleToString(double value)

Internal method used for conversion of a double to a string

Parameters:

value - the actual value

Returns:

the value converted to a string, according to the XPath casting rules.

negate

public NumericValue negate()

Negate the value

Specified by:

negate in class NumericValue

Returns:

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

floor

public NumericValue floor()

Implement the XPath floor() function

Specified by:

floor in class NumericValue

Returns:

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

ceiling

public NumericValue ceiling()

Implement the XPath ceiling() function

Specified by:

ceiling in class NumericValue

Returns:

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

round

public NumericValue round(int scale)

Implement the XPath round() function

Specified by:

round in class NumericValue

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 NumericValue roundHalfToEven(int scale)

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

Specified by:

roundHalfToEven in class NumericValue

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 int signum()

Determine whether the value is negative, zero, or positive

Specified by:

signum in class NumericValue

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

Overrides:

isNegativeZero in class NumericValue

Returns:

true if this value is float or double negative zero

isWholeNumber

public boolean isWholeNumber()

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

Specified by:

isWholeNumber in class NumericValue

Returns:

true if the value is a whole number

abs

public NumericValue abs()

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

Specified by:

abs in class NumericValue

Returns:

the absolute value

Since:

9.2

compareTo

public int compareTo(long other)

Compare the value to a long.

Specified by:

compareTo in class NumericValue

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

getSchemaComparable

public Comparable getSchemaComparable()

Get an object that implements XML Schema comparison semantics

Specified by:

getSchemaComparable in interface AtomicSequence

Specified by:

getSchemaComparable in class AtomicValue

Returns:

a Comparable that follows XML Schema comparison rules

asMapKey

public AtomicMatchKey asMapKey()

Get a value whose equals() method follows the "same key" rules for comparing the keys of a map.

Overrides:

asMapKey in class AtomicValue

Returns:

a value with the property that the equals() and hashCode() methods follow the rules for comparing keys in maps.

isIdentical

public boolean isIdentical(AtomicValue v)

Determine whether two atomic values are identical, as determined by XML Schema rules. This is a stronger test than equality (even schema-equality); for example two dateTime values are not identical unless they are in the same timezone.

Note that even this check ignores the type annotation of the value. The integer 3 and the short 3 are considered identical, even though they are not fully interchangeable. "Identical" means the same point in the value space, regardless of type annotation.

NaN is identical to itself.

Overrides:

isIdentical in class AtomicValue

Parameters:

v - the other value to be compared with this one

Returns:

true if the two values are identical, false otherwise.