com.saxonica.ee.stream.adjunct

Class ContextItemExprAdjunct

java.lang.Object

com.saxonica.ee.stream.adjunct.StreamingAdjunct

com.saxonica.ee.stream.adjunct.ContextItemExprAdjunct

public class ContextItemExprAdjunct
extends StreamingAdjunct

Constructor Summary

Constructors

Constructor and Description
ContextItemExprAdjunct()

Method Summary

Methods

Modifier and Type	Method and Description
PostureAndSweep	computeStreamability(boolean allowExtensions, ContextItemStaticInfo contextInfo, List<String> reasons) Compute the posture and sweep of this expression as defined in the W3C streamability specifications.
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.StreamingAdjunct

getConfiguration, getDefaultFeedMaker, getExpression, getFeedMaker, getWatchMaker, setConfiguration, setExpression

Methods inherited from class java.lang.Object

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

Constructor Detail

ContextItemExprAdjunct

public ContextItemExprAdjunct()

Method Detail

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

computeStreamability

public PostureAndSweep computeStreamability(boolean allowExtensions,
                                   ContextItemStaticInfo 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:

allowExtensions - if false, the definition of "guaranteed streamability" in the W3C specification is used. If true, Saxon extensions are permitted, which make some

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