Package net.sf.saxon.expr

Class BreakInstr

java.lang.Object
net.sf.saxon.expr.Expression
net.sf.saxon.instruct.Instruction
net.sf.saxon.expr.BreakInstr
All Implemented Interfaces:
Serializable, SourceLocator, LocationProvider, SaxonLocator, EvaluableItem, SequenceIterable, TailCallReturner, InstructionInfo, 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:

  • Field Details

  • Constructor Details

    • BreakInstr

      public BreakInstr()
      Create the instruction

  • Method Details

    • 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