net.sf.saxon.functions
Class VendorFunctionLibrary
java.lang.Object
net.sf.saxon.functions.VendorFunctionLibrary
- FunctionLibrary, Serializable
public class VendorFunctionLibrary
extends java.lang.Object
The VendorFunctionLibrary represents specially-recognized functions in the Saxon namespace. It doesn't
handle Saxon extension functions that are implemented as normal extension functions, which are bound using
the
JavaExtensionLibrary
.
Expression | bind(StructuredQName functionName, Expression[] staticArgs, StaticContext env) - Bind an extension function, given the URI and local parts of the function name,
and the list of expressions supplied as arguments.
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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.
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protected void | init()
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boolean | isAvailable(StructuredQName functionName, int arity) - Test whether a Saxon function with a given name and arity is available.
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Expression | makeSaxonFunction(String localName, StaticContext env, Expression[] arguments) - Make a Saxon function with a given name
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static String | pluralArguments(int num) - Utility routine used in constructing error messages
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protected StandardFunction.Entry | register(String name, Class implementationClass, int opcode, int minArguments, int maxArguments, ItemType itemType, int cardinality) - Register an extension function in the table of function details.
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VendorFunctionLibrary
public VendorFunctionLibrary()
Create the Vendor Function Library for Saxon
bind
public Expression bind(StructuredQName functionName,
Expression[] staticArgs,
StaticContext env)
throws XPathException
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.
- bind in interface FunctionLibrary
functionName
- the name of the functionstaticArgs
- 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
-
- 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.
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.
- copy in interface FunctionLibrary
- a copy of this function library. This must be an instance of the original class.
init
protected void init()
isAvailable
public boolean isAvailable(StructuredQName functionName,
int arity)
Test whether a Saxon 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.
- isAvailable in interface FunctionLibrary
functionName
- the name of the functionarity
- 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
makeSaxonFunction
public Expression makeSaxonFunction(String localName,
StaticContext env,
Expression[] arguments)
throws XPathException
Make a Saxon function with a given name
localName
- the local name of the functionenv
- the static contextarguments
- the arguments of the function
- an exprssion representing a call on the given function
pluralArguments
public static String pluralArguments(int num)
Utility routine used in constructing error messages
- the string " argument" or " arguments" if num is plural
register
protected StandardFunction.Entry register(String name,
Class implementationClass,
int opcode,
int minArguments,
int maxArguments,
ItemType itemType,
int cardinality)
Register an extension function in the table of function details.
name
- the function nameimplementationClass
- the class used to implement the functionopcode
- identifies the function when a single class implements several functionsminArguments
- the minimum number of arguments requiredmaxArguments
- the maximum number of arguments alloweditemType
- the item type of the result of the functioncardinality
- the cardinality of the result of the function
- the entry describing the function. The entry is incomplete, it does not yet contain information
about the function arguments.