Package net.sf.saxon.functions
Class IntegratedFunctionLibrary
java.lang.Object
net.sf.saxon.functions.IntegratedFunctionLibrary
- All Implemented Interfaces:
FunctionLibrary
A library of integrated function calls, that is, user-written extension functions implemented
as instances of the class
ExtensionFunctionDefinition
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionbind
(SymbolicName.F functionName, Expression[] staticArgs, Map<StructuredQName, Integer> keywords, StaticContext env, List<String> reasons) Bind an extension function, given the URI and local parts of the function name, and the list of expressions supplied as arguments.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.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, int languageLevel) Test whether a function with a given name and arity is availablestatic Expression
makeFunctionCall
(ExtensionFunctionDefinition defn, Expression[] staticArgs) void
registerFunction
(ExtensionFunctionDefinition function) Register an integrated function with this function libraryMethods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface net.sf.saxon.functions.FunctionLibrary
setConfiguration
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Constructor Details
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IntegratedFunctionLibrary
public IntegratedFunctionLibrary()
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Method Details
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registerFunction
Register an integrated function with this function library- Parameters:
function
- the implementation of the function (or set of functions)
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bind
public Expression bind(SymbolicName.F functionName, Expression[] staticArgs, Map<StructuredQName, Integer> keywords, StaticContext env, List<String> reasons) 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 interfaceFunctionLibrary
- Parameters:
functionName
- the QName and arity of the function being calledstaticArgs
- The expressions supplied statically in arguments to the function call. The length of this array represents the arity of the function. 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).
keywords
- May be null if no keywords are used in the function call. Otherwise, a map identifying the keywords appearing in the function call, and the 0-based position at which they appeared.env
- The static context of the function callreasons
- 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 object representing the function to be called, if one is found; null if no function was found matching the required name and arity.
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makeFunctionCall
public static Expression makeFunctionCall(ExtensionFunctionDefinition defn, Expression[] staticArgs) -
getFunctionItem
public FunctionItem 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.
- Specified by:
getFunctionItem
in interfaceFunctionLibrary
- Parameters:
functionName
- the qualified name of the function being calledstaticContext
- 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
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isAvailable
Test whether a function with a given name and arity is availableThis supports the function-available() function in XSLT.
- Specified by:
isAvailable
in interfaceFunctionLibrary
- Parameters:
functionName
- the qualified name of the function being calledlanguageLevel
- the XPath language level, times 10 (31 = XPath 3.1)- Returns:
- true if a function of this name and arity is available for calling
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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 interfaceFunctionLibrary
- Returns:
- a copy of this function library. This must be an instance of the original class.
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