Class SwitchAdjunct

  • All Implemented Interfaces:

    public class SwitchAdjunct
    extends TransmissionAdjunct
    Streaming code to implement a switch expression, which results from optimizing a choose where all the branches have similar test conditions. Unlike a choose, the conditions cannot be consuming: this is because the conditions must be similar, and if one is consuming then several will be consuming.
    • Constructor Detail

      • SwitchAdjunct

        public SwitchAdjunct()
    • Method Detail

      • setExpression

        public void setExpression​(Expression expression)
        Description copied from class: StreamingAdjunct
        Set the expression being processed by this StreamingAdjunct
        setExpression in class StreamingAdjunct
        expression - the expression being processed
      • getWatchMaker

        public WatchMaker getWatchMaker​(boolean forGrouping)
                                 throws XPathException
        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 value Expression.WATCH_METHOD
        getWatchMaker in class TransmissionAdjunct
        forGrouping - true if the selected items are being grouped
        a Watchmaker to evaluate the expression, or null if it is not streamable with respect to the specificed argument.
        XPathException - in the event of a failure
      • makeTransmissionFlow

        public Trigger makeTransmissionFlow​(WatchManager watchManager,
                                            Expression exp,
                                            ItemFeed out,
                                            XPathContext context)
                                     throws XPathException
        Description copied from class: TransmissionAdjunct
        Make a Trigger that implements this expression in streaming mode. This method is used for an expression that is striding or crawling, and it delivers a Trigger connected to a sequence of Feeds which together have the effect of delivering a sequence of events and/or items that together represent the results of this instruction. This method MUST be implemented for every expression that has an operand whose usage is transmission (and for every such operand).
        makeTransmissionFlow in class TransmissionAdjunct
        watchManager - the WatchManager that fires this trigger
        exp - the expression
        out - the next action in the push pipeline for evaluation
        context - the XPath dynamic context
        the Trigger (a Watch with a pattern)
        XPathException - if a dynamic evaluation error occurs.