net.sf.saxon.functions

Class ConstructorFunctionLibrary

java.lang.Object

net.sf.saxon.functions.ConstructorFunctionLibrary

All Implemented Interfaces:

FunctionLibrary

public class ConstructorFunctionLibrary
extends Object
implements FunctionLibrary

The ConstructorFunctionLibrary represents the collection of constructor functions for atomic types. These are provided for the built-in types such as xs:integer and xs:date, and also for user-defined atomic types.

Constructor Summary

Constructors

Constructor and Description
ConstructorFunctionLibrary(Configuration config) Create a SystemFunctionLibrary

Method Summary

Methods

Modifier and Type	Method and Description
Expression	bind(SymbolicName functionName, Expression[] arguments, StaticContext env, Container container) Bind a static function call, 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.
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

Constructor Detail

ConstructorFunctionLibrary

public ConstructorFunctionLibrary(Configuration config)

Create a SystemFunctionLibrary

Parameters:

config - the Configuration

Method Detail

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 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 - the container for the new function item

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)

Description copied from interface: FunctionLibrary

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, together with its arity. For legacy reasons, the arity may be set to -1 to mean any arity will do

Returns:

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

bind

public Expression bind(SymbolicName functionName,
              Expression[] arguments,
              StaticContext env,
              Container container)
                throws XPathException

Bind a static function call, 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 QName of the function

arguments - 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 - The static context

container - A container to provide location information for the expression

Returns:

An object representing the constructor function to be called, if one is found; null if no constructor 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.