net.sf.saxon.functions

Class CurrentMergeGroup

java.lang.Object

net.sf.saxon.om.AbstractItem

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.CurrentMergeGroup

All Implemented Interfaces:

Callable, Function, GroundedValue, Item, Sequence

public class CurrentMergeGroup
extends SystemFunction

Implements the XSLT 3.0 function current-merge-group()

Constructor Summary

Constructors

Constructor and Description
CurrentMergeGroup()

Method Summary

Modifier and Type	Method and Description
Sequence	call(XPathContext context, Sequence[] arguments) Evaluate the expression
MergeInstr	getControllingInstruction() Get the innermost containing xsl:merge instruction, if there is one
ItemType	getResultItemType() Determine the item type of the value returned by the function
int	getSpecialProperties(Expression[] arguments) Determine the special properties of this expression.
java.lang.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.
boolean	isInLoop() Determine whether the current-group() function is executed repeatedly within a single iteration of the containing xsl:for-each-group
Expression	makeFunctionCall(Expression... arguments) Make an expression that either calls this function, or that is equivalent to a call on this function
void	setControllingInstruction(MergeInstr instruction, boolean isInLoop) Set the containing xsl:merge instruction, if there is one

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

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

CurrentMergeGroup

public CurrentMergeGroup()

Method Detail

setControllingInstruction

public void setControllingInstruction(MergeInstr instruction,
                                      boolean isInLoop)
                               throws XPathException

Set the containing xsl:merge instruction, if there is one

Parameters:

instruction - the (innermost) containing xsl:merge instruction

isInLoop - true if the current-merge-group() expression is evaluated more than once during evaluation of the body of the for-each-group instruction

Throws:

XPathException - for example if the argument to the function is statically known and is not a valid source name

getControllingInstruction

public MergeInstr getControllingInstruction()

Get the innermost containing xsl:merge instruction, if there is one

Returns:

the innermost containing xsl:merge instruction

isInLoop

public boolean isInLoop()

Determine whether the current-group() function is executed repeatedly within a single iteration of the containing xsl:for-each-group

Returns:

true if it is evaluated repeatedly

getResultItemType

public ItemType getResultItemType()

Determine the item type of the value returned by the function

Overrides:

getResultItemType in class SystemFunction

getSpecialProperties

public int getSpecialProperties(Expression[] arguments)

Determine the special properties of this expression.

Overrides:

getSpecialProperties in class SystemFunction

Parameters:

arguments - the actual arguments supplied to the function call

Returns:

StaticProperty.NON_CREATIVE (unless the variable is assignable using saxon:assign)

makeFunctionCall

public Expression makeFunctionCall(Expression... arguments)

Make an expression that either calls this function, or that is equivalent to a call on this function

Overrides:

makeFunctionCall in class SystemFunction

Parameters:

arguments - the supplied arguments to the function call

Returns:

either a function call on this function, or an expression that delivers the same result

call

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

Evaluate the expression

Parameters:

context - the dynamic evaluation context

arguments - the values of the arguments, supplied as SequenceIterators

Returns:

the result of the evaluation, in the form of a SequenceIterator

Throws:

XPathException - if a dynamic error occurs during the evaluation of the expression

getStreamerName

public java.lang.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.