Class NumberFn

    • Constructor Detail

      • NumberFn

        public NumberFn()
    • Method Detail

      • simplify

        public Expression simplify​(ExpressionVisitor visitor)
                            throws XPathException
        Simplify and validate. This is a pure function so it can be simplified in advance if the arguments are known
        Overrides:
        simplify in class FunctionCall
        Parameters:
        visitor - an expression visitor
        Returns:
        the simplified expression
        Throws:
        XPathException - if an error is discovered during expression rewriting
      • typeCheck

        public Expression typeCheck​(ExpressionVisitor visitor,
                                    ExpressionVisitor.ContextItemType contextItemType)
                             throws XPathException
        Type-check the expression. This also calls preEvaluate() to evaluate the function if all the arguments are constant; functions that do not require this behavior can override the preEvaluate method.
        Overrides:
        typeCheck in class FunctionCall
        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 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)
      • addDocToPathMap

        public PathMap.PathMapNodeSet addDocToPathMap​(PathMap pathMap,
                                                      PathMap.PathMapNodeSet pathMapNodes)
        Add a representation of a doc() call or similar function to a PathMap. This is a convenience method called by the addToPathMap() methods for doc(), document(), collection() and similar functions. These all create a new root expression in the path map.
        Overrides:
        addDocToPathMap in class SystemFunction
        Parameters:
        pathMap - the PathMap to which the expression should be added
        pathMapNodes - the node in the PathMap representing the focus at the point where this expression is called. Set to null if this expression appears at the top level.
        Returns:
        the pathMapNode representing the focus established by this expression, in the case where this expression is the first operand of a path expression or filter expression
      • evaluateItem

        public Item evaluateItem​(XPathContext context)
                          throws XPathException
        Evaluate in a general context
        Overrides:
        evaluateItem in class Expression
        Parameters:
        context - The context in which the expression is to be evaluated
        Returns:
        the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence
        Throws:
        XPathException - if any dynamic error occurs evaluating the expression
      • convert

        public static DoubleValue convert​(AtomicValue value,
                                          Configuration config)
        Static method to perform the same conversion as the number() function. This is different from the convert(Type.DOUBLE) in that it produces NaN rather than an error for non-numeric operands.
        Parameters:
        value - the value to be converted
        config -
        Returns:
        the result of the conversion