net.sf.saxon.functions

Class VendorFunctionLibrary

public class VendorFunctionLibrary extends 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.
Constructor Summary
VendorFunctionLibrary()
Method Summary
Expressionbind(int nameCode, String uri, String local, Expression[] staticArgs)
Bind an extension function, given the URI and local parts of the function name, and the list of expressions supplied as arguments.
FunctionLibrarycopy()
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 voidinit()
booleanisAvailable(int fingerprint, String uri, String local, int arity)
Test whether a Saxon function with a given name and arity is available.
ExpressionmakeSaxonFunction(String localName, StaticContext env, Expression[] arguments)
Make a Saxon function with a given name
static StringpluralArguments(int num)
Utility routine used in constructing error messages
protected StandardFunction.Entryregister(String name, Class implementationClass, int opcode, int minArguments, int maxArguments, ItemType itemType, int cardinality)
Register an extension function in the table of function details.

Constructor Detail

VendorFunctionLibrary

public VendorFunctionLibrary()

Method Detail

bind

public Expression bind(int nameCode, String uri, String local, Expression[] staticArgs)
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.

Parameters: uri The URI of the function name local The local part of the function name 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.

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: net.sf.saxon.trans.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.

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.

Returns: a copy of this function library. This must be an instance of the original class.

init

protected void init()

isAvailable

public boolean isAvailable(int fingerprint, String uri, String local, 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.

Parameters: uri The URI of the function name local The local part of the function name 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 matching extension function, regardless of its arity.

makeSaxonFunction

public Expression makeSaxonFunction(String localName, StaticContext env, Expression[] arguments)
Make a Saxon function with a given name

pluralArguments

public static String pluralArguments(int num)
Utility routine used in constructing error messages

register

protected StandardFunction.Entry register(String name, 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.