net.sf.saxon.functions

Class SystemFunctionLibrary

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.
Field Summary
static intFULL_XSLT
static intUSE_WHEN
static intXPATH_ONLY
Constructor Summary
SystemFunctionLibrary(int functionSet)
Create a SystemFunctionLibrary
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.
booleanisAvailable(int fingerprint, String uri, String local, int arity)
Test whether a system function with a given name and arity is available.

Field Detail

FULL_XSLT

public static final int FULL_XSLT

USE_WHEN

public static final int USE_WHEN

XPATH_ONLY

public static final int XPATH_ONLY

Constructor Detail

SystemFunctionLibrary

public SystemFunctionLibrary(int functionSet)
Create a SystemFunctionLibrary

Parameters: functionSet determines the set of functions allowed. One of XPATH_ONLY, FULL_XSLT, USE_WHEN

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.

isAvailable

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

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.