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:

java.lang.Comparable, Expression, Item, java.io.Serializable

public final class DoubleValue

extends NumericValue

A numeric (double precision floating point) value

See Also:

Serialized Form

Field Summary
static DoubleValue	NaN
static DoubleValue	ZERO

 

Constructor Summary

DoubleValue(double value)           Constructor supplying a double

 

Method Summary
NumericValue	arithmetic(int operator, NumericValue other)           Evaluate a binary arithmetic operator.
double	asDouble()           Get the numeric value as a double
NumericValue	ceiling()           Implement the XPath ceiling() function
int	conversionPreference(java.lang.Class required, Configuration config)           Get conversion preference for this value to a Java class.
AtomicValue	convert(int requiredType)           Convert to target data type
java.lang.Object	convertToJava(java.lang.Class target, Configuration config)           Convert to Java object (for passing to external functions)
void	display(int level, NamePool pool)           Diagnostic print of expression structure
boolean	effectiveBooleanValue(XPathContext context)           Get the effective boolean value of the value
NumericValue	floor()           Implement the XPath floor() function
ItemType	getItemType()           Determine the data type of the expression
java.lang.String	getStringValue()           Get the value of the item as a string
double	getValue()           Get the value
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
NumericValue	round()           Implement the XPath round() function
NumericValue	roundToHalfEven(int scale)           Implement the XPath round-to-half-even() function

 

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

asLong, compareTo, equals, isInteger, promote, toString

 

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

convert, evaluateAsString, evaluateItem, getCardinality, getComponent, getPrimitiveValue, getTypedValue, iterate

 

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

analyze, asItem, asValue, collapseWhitespace, getDependencies, getSpecialProperties, getSubExpressions, inverse, normalizeWhitespace, promote, simplify, stringToNumber, trimWhitespace

 

Methods inherited from class java.lang.Object

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

 

Field Detail

ZERO

public static final DoubleValue ZERO

NaN

public static final DoubleValue NaN

DoubleValue

public DoubleValue(double value)

Constructor supplying a double

Parameters:

value - the value of the NumericValue

getValue

public double getValue()

Get the value

asDouble

public double asDouble()

Description copied from class: NumericValue

Get the numeric value as a double

Overrides:

asDouble in class NumericValue

Returns:

A double representing this numeric value; NaN if it 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 NumericValue

effectiveBooleanValue

public boolean effectiveBooleanValue(XPathContext context)

Description copied from class: AtomicValue

Get the effective boolean value of the value

Specified by:

effectiveBooleanValue in interface Expression

Overrides:

effectiveBooleanValue in class AtomicValue

Parameters:

context - the evaluation context (not used in this implementation)

Returns:

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

convert

public AtomicValue convert(int requiredType)
                    throws XPathException

Convert to target data type

Specified by:

convert in class AtomicValue

Parameters:

requiredType - an integer identifying the required atomic type

Returns:

an AtomicValue, a value of the required type

Throws:

XPathException - if the conversion is not possible

getStringValue

public java.lang.String getStringValue()

Description copied from interface: Item

Get the value of the item as a string

Specified by:

getStringValue in interface Item

Specified by:

getStringValue in class Value

Returns:

the string value of the item

getItemType

public ItemType getItemType()

Determine the data type of the expression

Returns:

Type.DOUBLE

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)

roundToHalfEven

public NumericValue roundToHalfEven(int scale)

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

Specified by:

roundToHalfEven 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

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

arithmetic

public NumericValue arithmetic(int operator,
                               NumericValue other)
                        throws XPathException

Evaluate a binary arithmetic operator.

Specified by:

arithmetic in class NumericValue

Parameters:

operator - the binary arithmetic operation to be performed. Uses the constants defined in the Tokenizer class

other - the other operand

Returns:

the result of the arithmetic operation

Throws:

XPathException - if an arithmetic error occurs

See Also:

Tokenizer

conversionPreference

public int conversionPreference(java.lang.Class required,
                                Configuration config)

Get conversion preference for this value to a Java class. A low result indicates higher preference.

Overrides:

conversionPreference in class AtomicValue

convertToJava

public java.lang.Object convertToJava(java.lang.Class target,
                                      Configuration config)
                               throws XPathException

Convert to Java object (for passing to external functions)

Overrides:

convertToJava in class AtomicValue

Parameters:

target - The class required by the external function

config - The configuration (needed for access to schema information)

Returns:

an object of the target class

XPathException

display

public void display(int level,
                    NamePool pool)

Diagnostic print of expression structure

Parameters:

level - indentation level for this expression