net.sf.saxon.functions

Class StringLength_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.StringLength_1

All Implemented Interfaces:

PullEvent, Callable, Function, GroundedValue, Item, Sequence

public class StringLength_1
extends ScalarSystemFunction

Implement the XPath string-length() function

Field Summary

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

ZERO_LENGTH_STRING

Constructor Summary

Constructors

Constructor and Description
StringLength_1()

Method Summary

Methods

Modifier and Type	Method and Description
AtomicValue	evaluate(Item arg, XPathContext context) Abstract method that must be supplied in subclasses to perform the evaluation
ExpressionCompiler	getExpressionCompiler() Return the compiler of the StringLength expression
IntegerValue[]	getIntegerBounds() For an expression that returns an integer or a sequence of integers, get a lower and upper bound on the values of the integers that may be returned, from static analysis.
ZeroOrOne<? extends AtomicValue>	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.

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

call, makeFunctionCall

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

equals, export, exportAttributes, getArity, getCardinality, getContextNode, getDescription, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getOperandRoles, getRequiredType, getResultItemType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getStreamingAdjunct, importAttributes, makeCall, makeFunction, makeOptimizedFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation, typeCheckCaller

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

atomize, deepEquals, effectiveBooleanValue, getStringValue, getStringValueCS, isArray, isMap, optimize, simplify, typeCheck

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

getLength, head, 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

StringLength_1

public StringLength_1()

Method Detail

getIntegerBounds

public IntegerValue[] getIntegerBounds()

For an expression that returns an integer or a sequence of integers, get a lower and upper bound on the values of the integers that may be returned, from static analysis. The default implementation returns null, meaning "unknown" or "not applicable". Other implementations return an array of two IntegerValue objects, representing the lower and upper bounds respectively. The values UNBOUNDED_LOWER and UNBOUNDED_UPPER are used by convention to indicate that the value may be arbitrarily large. The values MAX_STRING_LENGTH and MAX_SEQUENCE_LENGTH are used to indicate values limited by the size of a string or the size of a sequence.

Overrides:

getIntegerBounds in class SystemFunction

Returns:

the lower and upper bounds of integer values in the result, or null to indicate unknown or not applicable.

resultWhenEmpty

public ZeroOrOne<? extends AtomicValue> 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

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

getExpressionCompiler

public ExpressionCompiler getExpressionCompiler()

Return the compiler of the StringLength expression

Overrides:

getExpressionCompiler in class SystemFunction

Returns:

the relevant ExpressionCompiler