Class While

  • All Implemented Interfaces:
    ExportAgent, Locatable, IdentityComparable, Traceable

    public class While
    extends Instruction
    Handler for saxon:while elements in stylesheet.
    The saxon:while element has a mandatory attribute test, a boolean expression. The content is output repeatedly so long as the test condition is true.
    • Method Detail

      • setTest

        public void setTest​(Expression test)
      • setAction

        public void setAction​(Expression action)
      • operands

        public java.lang.Iterable<Operand> operands()
        Description copied from class: Expression
        Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression.

        If the expression is a Callable, then it is required that the order of the operands returned by this function is the same as the order of arguments supplied to the corresponding call() method.

        Specified by:
        operands in class Instruction
        Returns:
        an iterator containing the sub-expressions of this expression
      • getInstructionNameCode

        public int getInstructionNameCode()
        Get the name of this instruction for diagnostic and tracing purposes
        Overrides:
        getInstructionNameCode in class Instruction
        Returns:
        the string "saxon:while"
      • getActionExpression

        public Expression getActionExpression()
        Get the action expression (the content of the for-each)
      • copy

        public Expression copy​(RebindingMap rebindings)
        Copy an expression. This makes a deep copy.
        Specified by:
        copy in class Expression
        Parameters:
        rebindings - variables that need to be re-bound
        Returns:
        the copy of the original expression
      • getItemType

        public ItemType getItemType()
        Get the item type of the items returned by evaluating this instruction
        Overrides:
        getItemType in class Instruction
        Returns:
        the static item type of the instruction
      • mayCreateNewNodes

        public final boolean mayCreateNewNodes()
        Determine whether this instruction creates new nodes. This implementation returns true if the "action" creates new nodes. (Nodes created by the condition can't contribute to the result).
        Overrides:
        mayCreateNewNodes in class Instruction
        Returns:
        true if the instruction creates new nodes under some input conditions (or if it can't be proved that it doesn't)
      • export

        public void export​(ExpressionPresenter out)
                    throws XPathException
        Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
        Specified by:
        export in interface ExportAgent
        Specified by:
        export in class Expression
        Parameters:
        out - the expression presenter used to display the structure
        Throws:
        XPathException - if the export fails, for example if an expression is found that won't work in the target environment.