Class VendorFunctionLibrary

  • All Implemented Interfaces:
    java.io.Serializable, FunctionLibrary

    public class VendorFunctionLibrary
    extends java.lang.Object
    implements FunctionLibrary
    The VendorFunctionLibrary represents specially-recognized functions in the Saxon namespace. It doesn't handle Saxon extension functions that are implemented as normal extension functions, which are bound using the JavaExtensionLibrary.
    See Also:
    Serialized Form
    • Constructor Summary

      Constructors 
      Constructor Description
      VendorFunctionLibrary()
      Create the Vendor Function Library for Saxon
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      Expression bind​(StructuredQName functionName, Expression[] staticArgs, StaticContext env)
      Bind an extension function, given the URI and local parts of the function name, and the list of expressions supplied as arguments.
      FunctionLibrary copy()
      This method creates a copy of a FunctionLibrary: if the original FunctionLibrary allows new functions to be added, then additions to this copy will not affect the original, or vice versa.
      protected void init()  
      boolean isAvailable​(StructuredQName functionName, int arity)
      Test whether a Saxon function with a given name and arity is available.
      Expression makeSaxonFunction​(java.lang.String localName, StaticContext env, Expression[] arguments)
      Make a Saxon function with a given name
      static java.lang.String pluralArguments​(int num)
      Utility routine used in constructing error messages
      protected StandardFunction.Entry register​(java.lang.String name, java.lang.Class implementationClass, int opcode, int minArguments, int maxArguments, ItemType itemType, int cardinality)
      Register an extension function in the table of function details.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • VendorFunctionLibrary

        public VendorFunctionLibrary()
        Create the Vendor Function Library for Saxon
    • Method Detail

      • register

        protected StandardFunction.Entry register​(java.lang.String name,
                                                  java.lang.Class implementationClass,
                                                  int opcode,
                                                  int minArguments,
                                                  int maxArguments,
                                                  ItemType itemType,
                                                  int cardinality)
        Register an extension function in the table of function details.
        Parameters:
        name - the function name
        implementationClass - the class used to implement the function
        opcode - identifies the function when a single class implements several functions
        minArguments - the minimum number of arguments required
        maxArguments - the maximum number of arguments allowed
        itemType - the item type of the result of the function
        cardinality - the cardinality of the result of the function
        Returns:
        the entry describing the function. The entry is incomplete, it does not yet contain information about the function arguments.
      • init

        protected void init()
      • isAvailable

        public boolean isAvailable​(StructuredQName functionName,
                                   int arity)
        Test whether a Saxon function with a given name and arity is available. This supports the function-available() function in XSLT. This method may be called either at compile time or at run time.
        Specified by:
        isAvailable in interface FunctionLibrary
        Parameters:
        functionName - the name of the function
        arity - The number of arguments. This is set to -1 in the case of the single-argument function-available() function; in this case the method should return true if there is some
        Returns:
        true if a function of this name and arity is available for calling.
      • bind

        public Expression bind​(StructuredQName functionName,
                               Expression[] staticArgs,
                               StaticContext env)
                        throws XPathException
        Bind an extension function, given the URI and local parts of the function name, and the list of expressions supplied as arguments. This method is called at compile time.
        Specified by:
        bind in interface FunctionLibrary
        Parameters:
        functionName - the name of the function
        staticArgs - The expressions supplied statically in the function call. The intention is that the static type of the arguments (obtainable via getItemType() and getCardinality() may be used as part of the binding algorithm.
        env -
        Returns:
        An object representing the extension function to be called, if one is found; null if no extension function was found matching the required name and arity.
        Throws:
        XPathException - if a function is found with the required name and arity, but the implementation of the function cannot be loaded or used; or if an error occurs while searching for the function; or if this function library "owns" the namespace containing the function call, but no function was found.
      • makeSaxonFunction

        public Expression makeSaxonFunction​(java.lang.String localName,
                                            StaticContext env,
                                            Expression[] arguments)
                                     throws XPathException
        Make a Saxon function with a given name
        Parameters:
        localName - the local name of the function
        env - the static context
        arguments - the arguments of the function
        Returns:
        an exprssion representing a call on the given function
        Throws:
        XPathException
      • pluralArguments

        public static java.lang.String pluralArguments​(int num)
        Utility routine used in constructing error messages
        Parameters:
        num - a number
        Returns:
        the string " argument" or " arguments" if num is plural
      • copy

        public FunctionLibrary copy()
        This method creates a copy of a FunctionLibrary: if the original FunctionLibrary allows new functions to be added, then additions to this copy will not affect the original, or vice versa.
        Specified by:
        copy in interface FunctionLibrary
        Returns:
        a copy of this function library. This must be an instance of the original class.