Package net.sf.saxon.functions

Class ConstantFunction

    • Constructor Detail

      • ConstantFunction

        public ConstantFunction​(GroundedValue value)

    • Method Detail

      • call

        public Sequence call​(XPathContext context,
                     Sequence[] arguments)
              throws XPathException
        Description copied from interface: Callable
        Call the Callable.
        Parameters:
        context - the dynamic evaluation context
        arguments - the values of the arguments, supplied as Sequences.

        Generally it is advisable, if calling iterate() to process a supplied sequence, to call it only once; if the value is required more than once, it should first be converted to a GroundedValue by calling the utility method SequenceTool.toGroundedValue().

        If the expected value is a single item, the item should be obtained by calling Sequence.head(): it cannot be assumed that the item will be passed as an instance of Item or AtomicValue.

        It is the caller's responsibility to perform any type conversions required to convert arguments to the type expected by the callee. An exception is where this Callable is explicitly an argument-converting wrapper around the original Callable.

        Returns:
        the result of the evaluation, in the form of a Sequence. It is the responsibility of the callee to ensure that the type of result conforms to the expected result type.
        Throws:
        XPathException - if a dynamic error occurs during the evaluation of the expression

      • makeFunctionCall

        public Expression makeFunctionCall​(Expression[] arguments)
        Description copied from class: SystemFunction
        Make an expression that either calls this function, or that is equivalent to a call on this function
        Overrides:
        makeFunctionCall in class SystemFunction
        Parameters:
        arguments - the supplied arguments to the function call
        Returns:
        either a function call on this function, or an expression that delivers the same result

      • getIntegerBounds

        public IntegerValue[] getIntegerBounds()
        Description copied from class: SystemFunction
        For a function that returns an integer or a sequence of integers, get a lower and upper bound on the values of the integers that may be returned, from static analysis. The default implementation returns null, meaning "unknown" or "not applicable". Other implementations return an array of two IntegerValue objects, representing the lower and upper bounds respectively. The values UNBOUNDED_LOWER and UNBOUNDED_UPPER are used by convention to indicate that the value may be arbitrarily large. The values MAX_STRING_LENGTH and MAX_SEQUENCE_LENGTH are used to indicate values limited by the size of a string or the size of a sequence.
        Overrides:
        getIntegerBounds in class SystemFunction
        Returns:
        the lower and upper bounds of integer values in the result, or null to indicate unknown or not applicable.