net.sf.saxon.value
Class BooleanValue

java.lang.Object
  net.sf.saxon.value.Value
      net.sf.saxon.value.AtomicValue
          net.sf.saxon.value.BooleanValue

All Implemented Interfaces:

Serializable, Comparable, Expression, Item

public final class BooleanValue
extends AtomicValue
implements Comparable

A boolean XPath value

See Also:

Serialized Form

Field Summary

static BooleanValue	FALSE The boolean value FALSE
static BooleanValue	TRUE The boolean value TRUE

Method Summary

int	compareTo(Object other) Compare the value to another boolean value
int	conversionPreference(Class required) Get conversion preference for this value to a Java class.
AtomicValue	convert(int requiredType) Convert to target data type
Object	convertToJava(Class target) 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 this expression
boolean	equals(Object other) Determine whether two boolean values are equal
static BooleanValue	get(boolean value) Factory method: get a BooleanValue
ItemType	getItemType() Determine the data type of the expression
String	getStringValue() Convert to string
boolean	getValue() Get the value
int	hashCode() Get a hash code for comparing two BooleanValues
String	toString() Diagnostic display of this value as a string

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

convert, 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, stringToInteger, stringToNumber, trimWhitespace

Methods inherited from class java.lang.Object

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

Field Detail

TRUE

public static final BooleanValue TRUE

The boolean value TRUE

FALSE

public static final BooleanValue FALSE

The boolean value FALSE

Method Detail

get

public static BooleanValue get(boolean value)

Factory method: get a BooleanValue

Parameters:

value - true or false, to determine which boolean value is required

Returns:

the BooleanValue requested

getValue

public boolean getValue()

Get the value

Returns:

true or false, the actual boolean value of this BooleanValue

effectiveBooleanValue

public boolean effectiveBooleanValue(XPathContext context)

Get the effective boolean value of this expression

Specified by:

effectiveBooleanValue in interface Expression

Overrides:

effectiveBooleanValue in class AtomicValue

Parameters:

context - dynamic evaluation context, not used in this implementation

Returns:

the boolean value

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 String getStringValue()

Convert to string

Specified by:

getStringValue in interface Item

Returns:

"true" or "false"

getItemType

public ItemType getItemType()

Determine the data type of the expression

Specified by:

getItemType in interface Expression

Returns:

Type.BOOLEAN,

conversionPreference

public int conversionPreference(Class required)

Get conversion preference for this value to a Java class.

Overrides:

conversionPreference in class AtomicValue

Parameters:

required - the Java class to which the value is to be converted

Returns:

An integer giving the conversion preference. A low result indicates higher preference.

convertToJava

public Object convertToJava(Class target)
                     throws XPathException

Convert to Java object (for passing to external functions)

Overrides:

convertToJava in class AtomicValue

Parameters:

target - the Java class to which conversion is required

Returns:

An object of the specified Java class

Throws:

XPathException - if conversion is not possible or fails

compareTo

public int compareTo(Object other)

Compare the value to another boolean value

Specified by:

compareTo in interface Comparable

Parameters:

other - The other boolean value

Returns:

-1 if this one is the lower, 0 if they are equal, +1 if this one is the higher. False is considered to be less than true.

Throws:

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

equals

public boolean equals(Object other)

Determine whether two boolean values are equal

Overrides:

equals in class Object

Parameters:

other - the value to be compared to this value

Returns:

true if the other value is a boolean value and is equal to this value

hashCode

public int hashCode()

Get a hash code for comparing two BooleanValues

Overrides:

hashCode in class Object

Returns:

the hash code

display

public void display(int level,
                    NamePool pool)

Diagnostic print of expression structure

Specified by:

display in interface Expression

Parameters:

level - indentation level of output

toString

public String toString()

Diagnostic display of this value as a string

Overrides:

toString in class Object

Returns:

a string representation of this value: "true()" or "false()"