Package com.saxonica.ee.stream.adjunct

Class RootExpressionAdjunct

java.lang.Object
com.saxonica.ee.stream.adjunct.StreamingAdjunct
com.saxonica.ee.stream.adjunct.RootExpressionAdjunct
public class RootExpressionAdjunct extends StreamingAdjunct
Streaming code for an expression that does not support streaming

  • Constructor Details

    • RootExpressionAdjunct

      public RootExpressionAdjunct()

  • Method Details

    • 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(ContextItemStaticInfoEE contextInfo, List<String> reasons)
      Get the posture and 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 class StreamingAdjunct
      Parameters:
      contextInfo - Information about the context item for the expression
      reasons - the caller may supply a list, in which case the implementation may add to this
      Returns:
      the posture and sweep of the expression

    • getWatchMaker

      public WatchMaker getWatchMaker(boolean forGrouping) throws XPathException
      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 StreamingAdjunct
      Parameters:
      forGrouping - true if this is for for-each-group grouping
      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