Package com.saxonica.ee.stream.adjunct

Class SubsequenceStreamer

java.lang.Object

com.saxonica.ee.stream.adjunct.StreamingAdjunct

com.saxonica.ee.stream.adjunct.TransmissionAdjunct

com.saxonica.ee.stream.adjunct.FilteringAdjunct

com.saxonica.ee.stream.adjunct.SubsequenceStreamer

All Implemented Interfaces:

FeedMaker

public class SubsequenceStreamer
extends FilteringAdjunct
implements FeedMaker

Generate streaming code for a subsequence() function call. Also used for expressions such as tail() that compile into a subsequence() call

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SubsequenceStreamer.SubsequenceFilter

Constructor Summary

Constructors

Constructor	Description
SubsequenceStreamer()

Method Summary

Modifier and Type	Method	Description
FeedMaker	getFeedMaker(int arg)	Get a FeedMaker, a factory class that creates a Feed to evaluate this expression in streaming mode.
FilteringFeed.Filter	makeFilter(XPathContext context, ItemFeed out)	Make a filter for the event stream

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

makeItemFeed

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

getWatchMaker, makeTransmissionFlow

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

computeStreamability, emptyAdjunctMap, findConsumingArg, genId, getConfiguration, getDefaultFeedMaker, getExpression, makeStreamingAdjunct, setConfiguration, setExpression, toStreamingPattern

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.saxonica.ee.stream.feed.FeedMaker

makeItemFeed

Constructor Detail

SubsequenceStreamer

public SubsequenceStreamer()

Method Detail

getFeedMaker

public FeedMaker getFeedMaker(int arg)
                       throws XPathException

Description copied from class: StreamingAdjunct

Get a FeedMaker, a factory class that creates a Feed to evaluate this expression in streaming mode. In many cases the StreamingAdjunct is itself a FeedMaker, in which case it returns itself. But where an expression has several operands, it will typically create different feeds depending on which argument is the streamed input, and in such cases the individual StreamingAdjunct makes the decision which feed to use, by returning an appropriate FeedMaker.

Overrides:

getFeedMaker in class StreamingAdjunct

Parameters:

arg - identifies the argument with respect to which the expression is to be inverted: usually 0 to indicate the first argument is the value that is streamed. Argument numbering is the same as the sequence of arguments/operands returned by the method Expression.operands()

Returns:

a FeedMaker 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

makeFilter

public FilteringFeed.Filter makeFilter(XPathContext context,
                                       ItemFeed out)
                                throws XPathException

Description copied from class: FilteringAdjunct

Make a filter for the event stream

Specified by:

makeFilter in class FilteringAdjunct

Parameters:

context - the XPath dynamic context

out - the destination for the filtered events

Returns:

a filter that can be added to the event stream

Throws:

XPathException - if a dynamic evaluation error occurs