net.sf.saxon.query
public class UnboundFunctionLibrary extends Object implements FunctionLibrary
Constructor Summary | |
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UnboundFunctionLibrary()
Create an XQueryFunctionLibrary |
Method Summary | |
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Expression | bind(StructuredQName functionName, Expression[] arguments, StaticContext env)
Identify a (namespace-prefixed) function appearing in the expression. |
void | bindUnboundFunctionCalls(XQueryFunctionBinder lib, Configuration config)
Bind function calls that could not be bound when first encountered. |
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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SequenceType[] | getFunctionSignature(StructuredQName functionName, int arity)
Test whether a function with a given name and arity is available. |
Note that a function call may appear earlier in the query than the definition of the function to which it is bound. Unlike XSLT, we cannot search forwards to find the function definition. Binding of function calls is therefore a two-stage process; at the time the function call is parsed, we simply register it as pending; subsequently at the end of query parsing all the pending function calls are resolved. Another consequence of this is that we cannot tell at the time a function call is parsed whether it is a call to an internal (XSLT or XQuery) function or to an extension function written in Java.
Returns: an Expression representing the function call. This will normally be a FunctionCall, but it may be rewritten as some other expression.
Throws: net.sf.saxon.trans.XPathException if the function call is invalid, either because it is an unprefixed call to a non-system function, or because it is calling a system function that is available in XSLT only. A prefixed function call that cannot be recognized at this stage is assumed to be a forwards reference, and is bound later when bindUnboundFunctionCalls() is called.
Parameters: lib A library containing all the XQuery functions that have been declared; the method searches this library for this missing function call config The Saxon configuration
Throws: XPathException if a function call refers to a function that has not been declared
Returns: a copy of this function library. This must be an instance of the original class.
Parameters: functionName the name of the function required arity The number of arguments. This is set to -1 in the case of the single-argument