Class SimpleStepExpression

    • Constructor Detail

    • Method Detail

      • getOperandRole

        protected OperandRole getOperandRole​(int arg)
        Description copied from class: BinaryExpression
        Get the operand role
        Overrides:
        getOperandRole in class SlashExpression
        Parameters:
        arg - which argument: 0 for the lhs, 1 for the rhs
        Returns:
        the operand role
      • typeCheck

        public Expression typeCheck​(ExpressionVisitor visitor,
                                    ContextItemStaticInfo contextInfo)
                             throws XPathException
        Description copied from class: SlashExpression
        Type-check the expression
        Overrides:
        typeCheck in class SlashExpression
        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
        Description copied from class: BinaryExpression
        Perform optimisation of an expression and its subexpressions.

        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 SlashExpression
        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)
      • iterate

        public SequenceIterator iterate​(XPathContext context)
                                 throws XPathException
        Evaluate the expression, returning an iterator over the result
        Overrides:
        iterate in class SlashExpression
        Parameters:
        context - the evaluation context
        Returns:
        a SequenceIterator that can be used to iterate over the result of the expression
        Throws:
        XPathException - if any dynamic error occurs evaluating the expression
      • getExpressionName

        public java.lang.String getExpressionName()
        Description copied from class: Expression
        Get a name identifying the kind of expression, in terms meaningful to a user.
        Overrides:
        getExpressionName in class SlashExpression
        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 export() output displaying the expression.