Class BreakInstr

  • All Implemented Interfaces:
    java.io.Serializable, javax.xml.transform.SourceLocator, LocationProvider, SaxonLocator, EvaluableItem, SequenceIterable, TailCallReturner, InstructionInfo, org.xml.sax.Locator

    public class BreakInstr
    extends Instruction
    A compiled saxon:break instruction. The effect of executing this instruction is to register with the dynamic context that a tail call on a pseudo-function break() has been made; the enclosing saxon:iterate loop detects this tail call request and uses it as a signal to terminate execution of the loop.
    See Also:
    Serialized Form
    • Constructor Detail

      • BreakInstr

        public BreakInstr()
        Create the instruction
    • Method Detail

      • simplify

        public Expression simplify​(ExpressionVisitor visitor)
                            throws XPathException
        Description copied from class: Instruction
        Simplify an expression. This performs any static optimization (by rewriting the expression as a different expression). The default implementation does nothing.
        Specified by:
        simplify in class Instruction
        Parameters:
        visitor - an expression visitor
        Returns:
        the simplified expression
        Throws:
        XPathException - if an error is discovered during expression rewriting
      • copy

        public Expression copy()
        Description copied from class: Expression
        Copy an expression. This makes a deep copy.
        Specified by:
        copy in class Expression
        Returns:
        the copy of the original expression
      • createsNewNodes

        public boolean createsNewNodes()
        Description copied from class: Instruction
        Determine whether this instruction creates new nodes. This implementation returns a default value of false
        Overrides:
        createsNewNodes in class Instruction
        Returns:
        true if the instruction creates new nodes (or if it can't be proved that it doesn't)
      • processLeavingTail

        public TailCall processLeavingTail​(XPathContext context)
                                    throws XPathException
        Description copied from class: Instruction
        ProcessLeavingTail: called to do the real work of this instruction. This method must be implemented in each subclass. The results of the instruction are written to the current Receiver, which can be obtained via the Controller.
        Specified by:
        processLeavingTail in interface TailCallReturner
        Specified by:
        processLeavingTail in class Instruction
        Parameters:
        context - The dynamic context of the transformation, giving access to the current node, the current variables, etc.
        Returns:
        null if the instruction has completed execution; or a TailCall indicating a function call or template call that is delegated to the caller, to be made after the stack has been unwound so as to save stack space.
        Throws:
        XPathException
      • explain

        public void explain​(ExpressionPresenter out)
        Description copied from class: Expression
        Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
        Specified by:
        explain in class Expression
        Parameters:
        out - the expression presenter used to display the structure