Class Concat

    • Constructor Detail

      • Concat

        public Concat()
    • Method Detail

      • resultIfEmpty

        protected Sequence resultIfEmpty​(int arg)
        Description copied from class: SystemFunction
        Ask if the function always returns a known result when one of the arguments is an empty sequence
        Overrides:
        resultIfEmpty in class SystemFunction
        Parameters:
        arg - the argument whose value is an empty sequence (counting from zero)
        Returns:
        the value to be returned when this argument is an empty sequence, or null if unknown / not applicable
      • makeOptimizedFunctionCall

        public Expression makeOptimizedFunctionCall​(ExpressionVisitor visitor,
                                                    ContextItemStaticInfo contextInfo,
                                                    Expression... arguments)
                                             throws XPathException
        Allow the function to create an optimized call based on the values of the actual arguments
        Overrides:
        makeOptimizedFunctionCall in class SystemFunction
        Parameters:
        visitor - the expression visitor
        contextInfo - information about the context item
        arguments - the supplied arguments to the function call. Note: modifying the contents of this array should not be attempted, it is likely to have no effect.
        Returns:
        either a function call on this function, or an expression that delivers the same result, or null indicating that no optimization has taken place
        Throws:
        XPathException - if an error is detected
      • call

        public StringValue call​(XPathContext context,
                                Sequence[] arguments)
                         throws XPathException
        Description copied from interface: Function
        Invoke the function
        Specified by:
        call in interface Callable
        Specified by:
        call in interface Function
        Parameters:
        context - the XPath dynamic evaluation context
        arguments - the actual arguments to be supplied
        Returns:
        the result of invoking the function
        Throws:
        XPathException - if a dynamic error occurs within the function
      • process

        public void process​(Outputter destination,
                            XPathContext context,
                            Sequence[] arguments)
                     throws XPathException
        Description copied from interface: PushableFunction
        Evaluate the function in "push" mode
        Specified by:
        process in interface PushableFunction
        Parameters:
        destination - the destination for the function result
        context - the dynamic evaluation context
        arguments - the supplied arguments to the function
        Throws:
        XPathException - if a dynamic error occurs during the evaluation
      • getRequiredType

        public SequenceType getRequiredType​(int arg)
        Get the required type of the nth argument
        Overrides:
        getRequiredType in class SystemFunction
        Parameters:
        arg - the number of the argument whose type is requested, zero-based
        Returns:
        the required type of the argument as defined in the function signature
      • getCompilerName

        public java.lang.String getCompilerName()
        Description copied from class: SystemFunction
        Get the (local) name of a class that can be used to generate bytecode for this system function
        Overrides:
        getCompilerName in class SystemFunction
        Returns:
        the name of a bytecode generation class, or null if there is no bytecode support for this function