Package com.saxonica.ee.stream.adjunct

Class ForEachAdjunct

java.lang.Object

com.saxonica.ee.stream.adjunct.StreamingAdjunct

com.saxonica.ee.stream.adjunct.TransmissionAdjunct

com.saxonica.ee.stream.adjunct.ForEachAdjunct

All Implemented Interfaces:

FeedMaker

Direct Known Subclasses:

ForEachGroupAdjunct

public class ForEachAdjunct
extends TransmissionAdjunct
implements FeedMaker

Compile an xsl:for-each instruction to streaming code. Also handles a path expression (SlashExpression).

Constructor Summary

Constructors

Constructor	Description
ForEachAdjunct()

Method Summary

Modifier and Type	Method	Description
PostureAndSweep	computeStreamability(ContextItemStaticInfoEE contextInfo, List<String> reasons)	Compute the posture and sweep of this expression as defined in the W3C streamability specifications.
protected Inversion	getActionInversion(boolean forGrouping)
static PostureAndSweep	getStreamability(ContextSwitchingExpression expression, ContextItemStaticInfoEE contextInfo, List<String> reasons)
WatchMaker	getWatchMaker(boolean forGrouping)	Get a WatchMaker, a factory class that creates a Watch to evaluate this expression in streaming mode.
ItemFeed	makeItemFeed(WatchManager watchManager, ItemFeed out, XPathContext context)
void	setExpression(Expression expression)	Set the expression being processed by this StreamingAdjunct
Pattern	toStreamingPattern(Configuration config)	Convert this expression to a streaming pattern (a pattern used internally to match nodes during push processing of an event stream)

Methods inherited from class com.saxonica.ee.stream.adjunct.TransmissionAdjunct

makeTransmissionFlow

Methods inherited from class com.saxonica.ee.stream.adjunct.StreamingAdjunct

emptyAdjunctMap, findConsumingArg, genId, getConfiguration, getDefaultFeedMaker, getExpression, getFeedMaker, makeStreamingAdjunct, setConfiguration

Methods inherited from class java.lang.Object

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

Constructor Details

ForEachAdjunct

public ForEachAdjunct()

Method Details

setExpression

public void setExpression(Expression expression)

Set the expression being processed by this StreamingAdjunct

Overrides:

setExpression in class StreamingAdjunct

Parameters:

expression - the expression being processed

toStreamingPattern

public Pattern toStreamingPattern(Configuration config)

Convert this expression to a streaming pattern (a pattern used internally to match nodes during push processing of an event stream)

Overrides:

toStreamingPattern in class StreamingAdjunct

Parameters:

config - the Saxon configuration

Returns:

the equivalent pattern if conversion succeeds; otherwise null

getActionInversion

protected Inversion getActionInversion(boolean forGrouping)
                                throws XPathException

Throws:

XPathException

getWatchMaker

public WatchMaker getWatchMaker(boolean forGrouping)
                         throws XPathException

Description copied from class: StreamingAdjunct

Get a WatchMaker, a factory class that creates a Watch to evaluate this expression in streaming mode. This method will only be called if the getImplementationMethod() method of the expression includes the value Expression.WATCH_METHOD

Overrides:

getWatchMaker in class TransmissionAdjunct

Parameters:

forGrouping - true if the selected items are being grouped

Returns:

a Watchmaker to evaluate the expression, or null if it is not streamable with respect to the specificed argument.

Throws:

XPathException - in the event of a failure

makeItemFeed

public ItemFeed makeItemFeed(WatchManager watchManager,
 ItemFeed out,
 XPathContext context)
                      throws XPathException

Specified by:

makeItemFeed in interface FeedMaker

Throws:

XPathException

computeStreamability

public PostureAndSweep computeStreamability(ContextItemStaticInfoEE contextInfo,
 List<String> reasons)

Description copied from class: StreamingAdjunct

Compute the posture and sweep of this expression as defined in the W3C streamability specifications. This must be implemented in all subclasses that don't use the general streamability rules. The implementation should have the side-effect of computing the streamability of all subexpressions, recursively.

Overrides:

computeStreamability in class StreamingAdjunct

Parameters:

contextInfo - Information about the context item type and posture

reasons - the caller may supply a list, in which case the implementation may add to this; the contents are human-readable messages explaining why the expression is not streamable.

Returns:

the posture and sweep of the expression

getStreamability

public static PostureAndSweep getStreamability(ContextSwitchingExpression expression,
 ContextItemStaticInfoEE contextInfo,
 List<String> reasons)