Package net.sf.saxon.functions

Class CollatingFunctionFree

java.lang.Object

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.CollatingFunctionFree

All Implemented Interfaces:

Callable, FunctionItem, GroundedValue, Item, Sequence

public class CollatingFunctionFree
extends SystemFunction

Generic class for all functions that take an optional collation argument, where the collation argument is supplied and has not yet been resolved. The class provides methods that either do early evaluation of the collation argument (converting the function to the corresponding instance of CollatingFunctionFixed, or failing that, the collation argument is evaluated at run-time.

Constructor Summary

Constructors

Constructor	Description
CollatingFunctionFree()

Method Summary

Modifier and Type	Method	Description
CollatingFunctionFixed	bindCollation(String collationName)	Create an instance of (a subclass of) CollatingFunctionFixed representing the underlying function but with the collator already bound
Sequence	call(XPathContext context, Sequence[] args)	Invoke the function.
static String	expandCollationURI(String collationName, URI expressionBaseURI)	Expand a collation URI, which may be a relative URI reference
protected int	getCollationArgument()	Get the argument position (0-based) containing the collation name
String	getStreamerName()	Get a name that identifies the class that can be used to evaluate this function in streaming mode, that is, supplying one item or event at a time as it is delivered by the parser.
Expression	makeOptimizedFunctionCall(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo, Expression... arguments)	Allow the function to create an optimized call based on the values of the actual arguments

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

dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getCardinality, getContextNode, getDescription, getDetails, getElaborator, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getIntegerBounds, getNetCost, getOperandRoles, getRequiredType, getResultItemType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getUniStringArg, hashCode, importAttributes, isSequenceVariadic, isTrustedResultType, makeCall, makeFunction, makeFunction40, makeFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation, toShortString, toString, typeCheckCaller

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

atomize, deepEqual40, deepEquals, effectiveBooleanValue, getAnnotations, getUnicodeStringValue, isArray, isMap, makeNewContext, simplify, typeCheck

Methods inherited from class java.lang.Object

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

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

getGenre

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

asIterable, concatenate, containsNode, materialize

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

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

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

makeRepeatable

Constructor Details

CollatingFunctionFree

public CollatingFunctionFree()

Method Details

getCollationArgument

protected int getCollationArgument()

Get the argument position (0-based) containing the collation name

Returns:

the position of the argument containing the collation URI

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

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

bindCollation

public CollatingFunctionFixed bindCollation(String collationName)
                                     throws XPathException

Create an instance of (a subclass of) CollatingFunctionFixed representing the underlying function but with the collator already bound

Parameters:

collationName - the name of the collation to be used

Returns:

a function to implement this function with a fixed collation

Throws:

XPathException - if the collation is unknown

expandCollationURI

public static String expandCollationURI(String collationName,
 URI expressionBaseURI)
                                 throws XPathException

Expand a collation URI, which may be a relative URI reference

Parameters:

collationName - the collation URI as provided

expressionBaseURI - the base URI against which the collation URI will be resolved if it is relative

Returns:

the resolved (expanded) absolute collation URI

Throws:

XPathException - if the collation URI cannot be resolved

call

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

Invoke the function. This is done in effect by currying the function: that is, creating a new function in which the collation argument is bound, and then invoking that new function.

Parameters:

context - the XPath dynamic evaluation context

args - the actual arguments to be supplied

Returns:

the result of invoking the function

Throws:

XPathException - if a dynamic error occurs within the function

getStreamerName

public String getStreamerName()

Description copied from class: SystemFunction

Get a name that identifies the class that can be used to evaluate this function in streaming mode, that is, supplying one item or event at a time as it is delivered by the parser. Special streaming support is generally available in Saxon-EE for all system functions that take a sequence as their argument.

Overrides:

getStreamerName in class SystemFunction

Returns:

a name that identifies a class that supports streamed evaluation of this system function, or null if no such class is available. The mapping of names to classes is defined in the Saxon-EE class StreamerMap. In non-streaming Saxon editions (HE and PE) the method always returns null.