net.sf.saxon.functions

Class StartsWith

java.lang.Object

net.sf.saxon.om.AbstractItem

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.CollatingFunctionFixed

net.sf.saxon.functions.StartsWith

All Implemented Interfaces:

Callable, StatefulSystemFunction, Function, GroundedValue, Item, Sequence

public class StartsWith
extends CollatingFunctionFixed

Implements the fn:starts-with() function, with the collation already known

Constructor Summary

Constructors

Constructor and Description
StartsWith()

Method Summary

Modifier and Type	Method and Description
BooleanValue	call(XPathContext context, Sequence[] arguments) Evaluate the function
java.lang.String	getCompilerName() Get the (local) name of a class that can be used to generate bytecode for this system function
boolean	isSubstringMatchingFunction() Ask whether this function needs a collation that can handle substring matching
Expression	makeOptimizedFunctionCall(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo, Expression... arguments) Allow the function to create an optimized call based on the values of the actual arguments
static boolean	startsWith(StringValue arg0, StringValue arg1, SubstringMatcher collator)

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

copy, exportAttributes, getAtomicComparer, getPreAllocatedAtomicComparer, getStringCollator, importAttributes, preAllocateComparer, setCollationName, setRetainedStaticContext

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

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

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

StartsWith

public StartsWith()

Method Detail

isSubstringMatchingFunction

public boolean isSubstringMatchingFunction()

Description copied from class: CollatingFunctionFixed

Ask whether this function needs a collation that can handle substring matching

Overrides:

isSubstringMatchingFunction in class CollatingFunctionFixed

Returns:

true in the case of functions such as contains() and starts-with() where substring matching is required. Returns false by default;

makeOptimizedFunctionCall

public Expression makeOptimizedFunctionCall(ExpressionVisitor visitor,
                                            ContextItemStaticInfo contextInfo,
                                            Expression... arguments)
                                     throws XPathException

Allow the function to create an optimized call based on the values of the actual arguments

Overrides:

makeOptimizedFunctionCall in class SystemFunction

Parameters:

visitor - the expression visitor

contextInfo - information about the context item

arguments - the supplied arguments to the function call. Note: modifying the contents of this array should not be attempted, it is likely to have no effect.

Returns:

either a function call on this function, or an expression that delivers the same result, or null indicating that no optimization has taken place

Throws:

XPathException - if an error is detected

startsWith

public static boolean startsWith(StringValue arg0,
                                 StringValue arg1,
                                 SubstringMatcher collator)
                          throws XPathException

Throws:

XPathException

call

public BooleanValue call(XPathContext context,
                         Sequence[] arguments)
                  throws XPathException

Evaluate the function

Parameters:

context - the XPath dynamic evaluation context

arguments - the actual arguments to be supplied

Returns:

the result of invoking the function

Throws:

XPathException - if a dynamic error occurs within the function

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