All Known Subinterfaces:

XQueryFunctionBinder

All Known Implementing Classes:

ArrayFunctionSet, BuiltInFunctionSet, ConstructorFunctionLibrary, ExecutableFunctionLibrary, EXPathFileFunctionSet, ExsltCommonFunctionSet, FunctionLibraryList, ImportedFunctionLibrary, IntegratedFunctionLibrary, IXSLFunctionSet, JavaExtensionLibrary, JSFunctionLibrary, MapFunctionSet, MathFunctionSet, OnDemandFunctionSet, PublicStylesheetFunctionLibrary, SQLFunctionSet, StylesheetFunctionLibrary, UnboundFunctionLibrary, UseWhen30FunctionSet, VendorFunctionSetEE, VendorFunctionSetHE, VendorFunctionSetPE, XPath20FunctionSet, XPath30FunctionSet, XPath31FunctionSet, XPathFunctionLibrary, XQueryFunctionLibrary, XQUpdate10FunctionSet, XSLOriginalLibrary, XSLT30FunctionSet
```
public interface FunctionLibrary
```
A FunctionLibrary handles the binding of function calls in XPath (or XQuery) expressions. There are a number of implementations of this class to handle different kinds of function: system functions, constructor functions, vendor-defined functions, Java extension functions, stylesheet functions, and so on. There is also an implementation FunctionLibraryList that allows a FunctionLibrary to be constructed by combining other FunctionLibrary objects.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`Expression`	`bind(SymbolicName.F functionName, Expression[] staticArgs, StaticContext env, java.util.List<java.lang.String> reasons)`	Bind a 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.
`Function`	`getFunctionItem(SymbolicName.F functionName, StaticContext staticContext)`	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.F functionName)`	Test whether a function with a given name and arity is available
`default void`	`setConfiguration(Configuration config)`

- Method Detail
  - setConfiguration
```
default void setConfiguration(Configuration config)
```
  - isAvailable
```
boolean isAvailable(SymbolicName.F functionName)
```
    Test whether a function with a given name and arity is available
    This supports the function-available() function in XSLT.
    
    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
```
Expression bind(SymbolicName.F functionName,
                Expression[] staticArgs,
                StaticContext env,
                java.util.List<java.lang.String> reasons)
```
    Bind a 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 - the QName of the function being called
    
    staticArgs - May be null; if present, the length of the array must match the value of arity. Contains the expressions supplied statically in arguments to 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. In some cases it may be possible for the function to be pre-evaluated at compile time, for example if these expressions are all constant values.
    The conventions of the XPath language demand that the results of a function depend only on the values of the expressions supplied as arguments, and not on the form of those expressions. For example, the result of f(4) is expected to be the same as f(2+2). The actual expression is supplied here to enable the binding mechanism to select the most efficient possible implementation (including compile-time pre-evaluation where appropriate).
    
    env - The static context of the function call
    
    reasons - If no matching function is found by the function library, it may add a diagnostic explanation to this list explaining why none of the available functions could be used.
    
    Returns:
    
    An expression equivalent to a call on the specified function, if one is found; null if no function was found matching the required name and arity.
  - copy
```
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.
  - getFunctionItem
```
Function getFunctionItem(SymbolicName.F functionName,
                         StaticContext staticContext)
                  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.
    
    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
    
    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

Interface FunctionLibrary

Method Summary

Method Detail

setConfiguration

isAvailable

bind

copy

getFunctionItem