net.sf.saxon.functions

Class ConstructorFunctionLibrary

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
ConstructorFunctionLibrary(Configuration config)
Create a SystemFunctionLibrary
Method Summary
Expressionbind(StructuredQName functionName, Expression[] arguments, StaticContext env)
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.
SequenceType[]getFunctionSignature(StructuredQName functionName, int arity)
Test whether a system function with a given name and arity is available, and return its signature.

Constructor Detail

ConstructorFunctionLibrary

public ConstructorFunctionLibrary(Configuration config)
Create a SystemFunctionLibrary

Parameters: config the Configuration

Method Detail

bind

public Expression bind(StructuredQName functionName, Expression[] arguments, StaticContext env)
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: functionName 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

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.

getFunctionSignature

public SequenceType[] getFunctionSignature(StructuredQName functionName, int arity)
Test whether a system function with a given name and arity is available, and return its signature. This supports the function-available() function in XSLT. This method may be called either at compile time or at run time.

Parameters: functionName the name of the function arity The number of arguments. This is set to -1 in the case of the single-argument

Returns: if a function of this name and arity is available for calling, then the type signature of the function, as an array of sequence types in which the zeroth entry represents the return type; otherwise null