net.sf.saxon.functions

Class Number_1

java.lang.Object

net.sf.saxon.om.AbstractItem

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.ScalarSystemFunction

net.sf.saxon.functions.Number_1

All Implemented Interfaces:

Callable, Function, GroundedValue, Item, Sequence

public class Number_1
extends ScalarSystemFunction

Implements the XPath fn:number() function when called with one argument. Note: this function accepts the value "+INF" whether or not XSD 1.1 is enabled.

Field Summary

Fields inherited from class net.sf.saxon.functions.ScalarSystemFunction

ZERO_LENGTH_STRING

Constructor Summary

Constructors

Constructor and Description
Number_1()

Method Summary

Modifier and Type	Method and Description
static DoubleValue	convert(AtomicValue value, Configuration config) Static method to perform the same conversion as the number() function.
AtomicValue	evaluate(Item arg, XPathContext context) Abstract method that must be supplied in subclasses to perform the evaluation
java.lang.String	getCompilerName() Get the (local) name of a class that can be used to generate bytecode for this system function
ZeroOrOne<NumericValue>	resultWhenEmpty() Method that may be supplied in subclasses, to indicate the result that is returned when an empty sequence is supplied as the argument value.
static DoubleValue	toNumber(AtomicValue arg0) The actual implementation logic
Expression	typeCheckCaller(FunctionCall caller, ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) Type-check a calling expression.

Methods inherited from class net.sf.saxon.functions.ScalarSystemFunction

call, makeFunctionCall

Methods inherited from class net.sf.saxon.functions.SystemFunction

dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getCardinality, getContextNode, getDescription, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getIntegerBounds, getNetCost, getOperandRoles, getRequiredType, getResultItemType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getStreamerName, importAttributes, isTrustedResultType, makeCall, makeFunction, makeOptimizedFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation

Methods inherited from class net.sf.saxon.functions.AbstractFunction

atomize, deepEquals, effectiveBooleanValue, getAnnotations, getStringValue, getStringValueCS, isArray, isMap, makeNewContext, simplify, typeCheck

Methods inherited from class net.sf.saxon.om.AbstractItem

getLength, head, isStreamed, itemAt, iterate, reduce, subsequence

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

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

iterate

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

head

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

getLength, head, itemAt, reduce, subsequence

Constructor Detail

Number_1

public Number_1()

Method Detail

evaluate

public AtomicValue evaluate(Item arg,
                            XPathContext context)
                     throws XPathException

Description copied from class: ScalarSystemFunction

Abstract method that must be supplied in subclasses to perform the evaluation

Specified by:

evaluate in class ScalarSystemFunction

Parameters:

arg - the supplied argument

context - the dynamic context

Returns:

the result of the evaluation

Throws:

XPathException - if a dynamic error occurs

resultWhenEmpty

public ZeroOrOne<NumericValue> resultWhenEmpty()

Description copied from class: ScalarSystemFunction

Method that may be supplied in subclasses, to indicate the result that is returned when an empty sequence is supplied as the argument value. The default is to return the empty sequence

Overrides:

resultWhenEmpty in class ScalarSystemFunction

Returns:

the result of evaluation when the supplied argument is an empty sequence

typeCheckCaller

public Expression typeCheckCaller(FunctionCall caller,
                                  ExpressionVisitor visitor,
                                  ContextItemStaticInfo contextInfo)

Type-check a calling expression.

Overrides:

typeCheckCaller in class SystemFunction

toNumber

public static DoubleValue toNumber(AtomicValue arg0)
                            throws XPathException

The actual implementation logic

Parameters:

arg0 - the atomic value to be converted

Returns:

the result of the conversion

Throws:

XPathException

convert

public static DoubleValue convert(AtomicValue value,
                                  Configuration config)

Static method to perform the same conversion as the number() function. This is different from the convert(Type.DOUBLE) in that it produces NaN rather than an error for non-numeric operands.

Parameters:

value - the value to be converted

config - the Saxon configuration

Returns:

the result of the conversion

getCompilerName

public java.lang.String getCompilerName()

Description copied from class: SystemFunction

Get the (local) name of a class that can be used to generate bytecode for this system function

Overrides:

getCompilerName in class SystemFunction

Returns:

the name of a bytecode generation class, or null if there is no bytecode support for this function