net.sf.saxon.value
Class DoubleValue

java.lang.Object
  net.sf.saxon.value.Value
      net.sf.saxon.value.AtomicValue
          net.sf.saxon.value.NumericValue
              net.sf.saxon.value.DoubleValue

All Implemented Interfaces:

Serializable, Comparable, PullEvent, SequenceIterable, GroundedValue, Item, ValueRepresentation, ConversionResult

public final class DoubleValue
extends NumericValue

A numeric (double precision floating point) value

See Also:

Serialized Form

Field Summary

static DoubleValue	NaN
static DoubleValue	NEGATIVE_ZERO
static DoubleValue	ONE
static DoubleValue	ZERO

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

EMPTY_CLASS_ARRAY, INDETERMINATE_ORDERING

Fields inherited from interface net.sf.saxon.om.ValueRepresentation

EMPTY_VALUE_ARRAY

Fields inherited from interface net.sf.saxon.om.ValueRepresentation

EMPTY_VALUE_ARRAY

Constructor Summary

DoubleValue(CharSequence val)
Constructor supplying a string

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

NumericValue	ceiling() Implement the XPath ceiling() function
int	compareTo(long other) Compare the value to a long.
ConversionResult	convertPrimitive(BuiltInAtomicType requiredType, boolean validate, XPathContext context) Convert to target data type
Object	convertToJava(Class target, XPathContext context) Convert to Java object (for passing to external functions)
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.
double	getDoubleValue() Return this numeric value as a double
BuiltInAtomicType	getPrimitiveType() Determine the primitive type of the value.
Comparable	getSchemaComparable() Get an object that implements XML Schema comparison semantics
String	getStringValue() Convert the double to a string according to the XPath 2.0 rules
CharSequence	getStringValueCS() Convert the double to a string according to the XPath 2.0 rules
int	hashCode() Get the hashCode.
boolean	isNaN() Test whether the value is the double/float value NaN
boolean	isWholeNumber() Determine whether the value is a whole number, that is, whether it compares equal to some integer
NumericValue	negate() Negate the value
static void	printInternalForm(double d) Diagnostic method: print the sign, exponent, and significand
NumericValue	round() Implement the XPath round() function
NumericValue	roundHalfToEven(int scale) Implement the XPath round-to-half-even() function
double	signum() Determine whether the value is negative, zero, or positive

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

compareTo, equals, getDecimalValue, getFloatValue, getXPathComparable, isInteger, longValue, parseNumber, promote, toString

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

asAtomic, checkPermittedContents, convert, convert, getCardinality, getComponent, getItemType, getLength, getTypedValue, getTypeLabel, itemAt, iterate, process, setTypeLabel, subsequence

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

asItem, asItem, asIterator, asValue, convertJavaObjectToXPath, convertToJava, fromItem, getIterator, iterate, makeQNameValue, reduce, stringToNumber

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

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(CharSequence val)
            throws ValidationException

Constructor supplying a string

Parameters:

val - the string representation of the double value, conforming to the XML Schema lexical representation of xs:double, with leading and trailing spaces permitted

Throws:

ValidationException - if the string does not have the correct lexical form for a double. Note that the error will contain no error code or context information.

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

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

Overrides:

getDoubleValue in class NumericValue

Returns:

the value as a double

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; otherwise false

effectiveBooleanValue

public boolean effectiveBooleanValue()

Get the effective boolean value

Overrides:

effectiveBooleanValue in class AtomicValue

Returns:

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

convertPrimitive

public ConversionResult convertPrimitive(BuiltInAtomicType requiredType,
                                         boolean validate,
                                         XPathContext context)

Convert to target data type

Parameters:

requiredType - an integer identifying the required atomic type

validate - true if the supplied value must be validated, false if the caller warrants that it is valid

context - the XPath dynamic context

Returns:

an AtomicValue, a value of the required type

getStringValue

public String getStringValue()

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

Specified by:

getStringValue in interface Item

Specified by:

getStringValue in interface ValueRepresentation

Specified by:

getStringValue in class AtomicValue

Returns:

the string value

See Also:

Item.getStringValueCS()

getStringValueCS

public CharSequence getStringValueCS()

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

Specified by:

getStringValueCS in interface Item

Specified by:

getStringValueCS in interface ValueRepresentation

Overrides:

getStringValueCS in class AtomicValue

Returns:

the string value

See Also:

Item.getStringValue()

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.

Overrides:

getCanonicalLexicalRepresentation in class Value

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()

Implement the XPath round() function

Specified by:

round in class NumericValue

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 double 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), +1 if positive, NaN if NaN

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

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 class AtomicValue

Returns:

a Comparable that follows XML Schema comparison rules

convertToJava

public Object convertToJava(Class target,
                            XPathContext context)
                     throws XPathException

Convert to Java object (for passing to external functions)

Overrides:

convertToJava in class Value

Parameters:

target - the required target class

context - the XPath dynamic evaluation context

Returns:

the (boxed) Java object that best represents the XPath value

Throws:

XPathException

printInternalForm

public static void printInternalForm(double d)

Diagnostic method: print the sign, exponent, and significand

Parameters:

d - the double to be diagnosed