Class SourceDocument

    • Method Detail

      • setSpaceStrippingRule

        public void setSpaceStrippingRule​(SpaceStrippingRule rule)
        Set the whitespace stripping rule to be used. (This method is used when reloading the instruction from a SEF file)
        Parameters:
        rule - the whitespace stripping rule
      • getExpressionName

        public java.lang.String getExpressionName()
        Get a name identifying the kind of expression, in terms meaningful to a user.
        Overrides:
        getExpressionName in class Instruction
        Returns:
        a name identifying the kind of expression, in terms meaningful to a user. The name will always be in the form of a lexical XML QName, and should match the name used in explain() output displaying the expression.
      • getExportTag

        public java.lang.String getExportTag()
      • setHref

        public void setHref​(Expression href)
      • setBody

        public void setBody​(Expression body)
      • setUsedAccumulators

        public void setUsedAccumulators​(java.util.Set<? extends Accumulator> used)
      • 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
      • allowExtractingCommonSubexpressions

        public boolean allowExtractingCommonSubexpressions()
        Ask whether common subexpressions found in the operands of this expression can be extracted and evaluated outside the expression itself. The result is irrelevant in the case of operands evaluated with a different focus, which will never be extracted in this way, even if they have no focus dependency.
        Overrides:
        allowExtractingCommonSubexpressions in class Expression
        Returns:
        false for this kind of expression
      • typeCheck

        public Expression typeCheck​(ExpressionVisitor visitor,
                                    ContextItemStaticInfo contextInfo)
                             throws XPathException
        Perform type checking of an expression and its subexpressions. This is the second phase of static optimization.
        Overrides:
        typeCheck in class Expression
        Parameters:
        visitor - an expression visitor
        contextInfo - Information available statically about the context item: whether it is (possibly) absent; its static type; its streaming posture.
        Returns:
        the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
        Throws:
        XPathException - if an error is discovered during this phase (typically a type error)
      • optimize

        public Expression optimize​(ExpressionVisitor visitor,
                                   ContextItemStaticInfo contextItemType)
                            throws XPathException
        Perform optimisation of an expression and its subexpressions. This is the third and final phase of static optimization.

        This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.

        Overrides:
        optimize in class Expression
        Parameters:
        visitor - an expression visitor
        contextItemType - the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set to Type.ITEM_TYPE
        Returns:
        the original expression, rewritten if appropriate to optimize execution
        Throws:
        XPathException - if an error is discovered during this phase (typically a type error)
      • mayCreateNewNodes

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

        public int computeDependencies()
        Compute the dependencies of an expression, as the union of the dependencies of its subexpressions. (This is overridden for path expressions and filter expressions, where the dependencies of a subexpression are not all propogated). This method should be called only once, to compute the dependencies; after that, getDependencies should be used.
        Overrides:
        computeDependencies in class Expression
        Returns:
        the depencies, as a bit-mask
      • computeSpecialProperties

        protected int computeSpecialProperties()
        Get the static properties of this expression (other than its type). The result is bit-signficant. These properties are used for optimizations. In general, if property bit is set, it is true, but if it is unset, the value is unknown.
        Overrides:
        computeSpecialProperties in class Instruction
        Returns:
        a set of flags indicating static properties of this expression
      • 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.
      • 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
      • push

        public void push​(Outputter output,
                         XPathContext context)
                  throws XPathException
        Evaluate the instruction in push mode
        Parameters:
        output - the destination for the result
        context - the evaluation context
        Throws:
        XPathException - in the event of a failure
        QuitParsingException - if there was an early exit, that is, if the instruction was evaluated without reading the input to completion