Package com.saxonica.ee.stream.adjunct
Class VennExpressionAdjunct
java.lang.Object
com.saxonica.ee.stream.adjunct.StreamingAdjunct
com.saxonica.ee.stream.adjunct.TransmissionAdjunct
com.saxonica.ee.stream.adjunct.VennExpressionAdjunct
- All Implemented Interfaces:
FeedMaker
Class to handle streaming of union, intersect, and except expressions
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptioncomputeStreamability
(ContextItemStaticInfoEE contextInfo, List<String> reasons) Get the "sweep" of this expression as defined in the W3C streamability specifications.getWatchMaker
(boolean forGrouping) Get a WatchMaker, a factory class that creates a Watch to evaluate this expression in streaming mode.makeItemFeed
(WatchManager watchManager, ItemFeed out, XPathContext context) 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, setExpression
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Constructor Details
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Method Details
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toStreamingPattern
Convert this expression to a streaming pattern (a pattern used internally to match nodes during push processing of an event stream)- Overrides:
toStreamingPattern
in classStreamingAdjunct
- Parameters:
config
- the Saxon configuration- Returns:
- the equivalent pattern if conversion succeeds; otherwise null
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computeStreamability
public PostureAndSweep computeStreamability(ContextItemStaticInfoEE contextInfo, List<String> reasons) Get the "sweep" of this expression as defined in the W3C streamability specifications. This provides an assessment of stylesheet code against the W3C criteria for guaranteed streamability, and is implemented to allow these criteria to be tested. It is not the case that all expression that emerge as streamable from this analysis are currently capable of being streamed by Saxon- Overrides:
computeStreamability
in classStreamingAdjunct
- Parameters:
contextInfo
- static information about the context itemreasons
- the caller may supply a list, in which case the implementation may add to this- Returns:
- the posture and sweep of the expression
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getWatchMaker
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 valueExpression.WATCH_METHOD
- Overrides:
getWatchMaker
in classTransmissionAdjunct
- 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
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makeItemFeed
public ItemFeed makeItemFeed(WatchManager watchManager, ItemFeed out, XPathContext context) throws XPathException - Throws:
XPathException
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