net.sf.saxon.functions

Class SystemFunctionLibrary

java.lang.Object

net.sf.saxon.functions.SystemFunctionLibrary

All Implemented Interfaces:

FunctionLibrary

public class SystemFunctionLibrary
extends Object
implements FunctionLibrary

The SystemFunctionLibrary represents the collection of functions in the fn: namespace. That is, the functions defined in the "Functions and Operators" specification, optionally augmented by the additional functions defined in XSLT.

Method Summary

Methods

Modifier and Type	Method and Description
Expression	bind(SymbolicName symbolicName, Expression[] staticArgs, StaticContext env, Container container) 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.
FunctionItem	getFunctionItem(SymbolicName functionName, StaticContext staticContext, Container container) Test whether a function with a given name and arity is available; if so, return a function item that can be dynamically called.
static SystemFunctionLibrary	getSystemFunctionLibrary(int functionSet) Factory method to create or get a SystemFunctionLibrary
boolean	isAvailable(SymbolicName functionName) Test whether a function with a given name and arity is available

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getSystemFunctionLibrary

public static SystemFunctionLibrary getSystemFunctionLibrary(int functionSet)

Factory method to create or get a SystemFunctionLibrary

Parameters:

functionSet - determines the set of functions allowed. One or more of the bit settings StandardFunction.CORE, StandardFunction.XSLT, StandardFunction.XQUPDATE, etc

Returns:

the appropriate SystemFunctionLibrary

bind

public Expression bind(SymbolicName symbolicName,
              Expression[] staticArgs,
              StaticContext env,
              Container container)
                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:

symbolicName - the name and arity of the function to be bound

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 -

container -

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.

getFunctionItem

public FunctionItem getFunctionItem(SymbolicName functionName,
                           StaticContext staticContext,
                           Container container)
                             throws XPathException

Test whether a function with a given name and arity is available; if so, return a function item that can be dynamically called.

This supports the function-lookup() function in XPath 3.0.

Specified by:

getFunctionItem in interface FunctionLibrary

Parameters:

functionName - the qualified name and arity of the function being called

staticContext - the static context to be used by the function, in the event that it is a system function with dependencies on the static context

container -

Returns:

if a function of this name and arity is available for calling, then a corresponding function item; or null if the function does not exist

Throws:

XPathException - in the event of certain errors, for example attempting to get a function that is private

isAvailable

public boolean isAvailable(SymbolicName functionName)

Test whether a function with a given name and arity is available

This supports the function-available() function in XSLT.

Specified by:

isAvailable in interface FunctionLibrary

Parameters:

functionName - the qualified name of the function being called

Returns:

true if a function of this name and arity is available for calling

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.