Class RootExpressionAdjunct


  • public class RootExpressionAdjunct
    extends StreamingAdjunct
    Streaming code for an expression that does not support streaming
    • Constructor Detail

      • RootExpressionAdjunct

        public RootExpressionAdjunct()
    • 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​(ContextItemStaticInfoEE contextInfo,
                                                    java.util.List<java.lang.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