net.sf.saxon.functions
Class SystemFunctionLibrary

java.lang.Object
  extended by net.sf.saxon.functions.SystemFunctionLibrary
All Implemented Interfaces:
Serializable, 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.

See Also:
Serialized Form

Field Summary
static int FULL_XSLT
           
static int USE_WHEN
           
static int XPATH_ONLY
           
 
Method Summary
 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.
static SystemFunctionLibrary getSystemFunctionLibrary(int functionSet)
          Factory method to create or get a SystemFunctionLibrary
 boolean isAvailable(StructuredQName functionName, int arity)
          Test whether a system function with a given name and arity is available.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

XPATH_ONLY

public static final int XPATH_ONLY
See Also:
Constant Field Values

FULL_XSLT

public static final int FULL_XSLT
See Also:
Constant Field Values

USE_WHEN

public static final int USE_WHEN
See Also:
Constant Field Values
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 of XPATH_ONLY, FULL_XSLT, USE_WHEN
Returns:
the appropriate SystemFunctionLibrary

isAvailable

public boolean isAvailable(StructuredQName functionName,
                           int arity)
Test whether a system 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 being tested
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 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 -
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.

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.


Copyright (C) Michael H. Kay. All rights reserved.