package client.net.sf.saxon.ce.functions;
import client.net.sf.saxon.ce.expr.Container;
import client.net.sf.saxon.ce.expr.Expression;
import client.net.sf.saxon.ce.expr.StaticContext;
import client.net.sf.saxon.ce.om.StructuredQName;
import client.net.sf.saxon.ce.trans.XPathException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
/**
* A FunctionLibraryList is a list of FunctionLibraries. It is also a FunctionLibrary in its own right.
* When required, it searches the list of FunctionLibraries to find the required function.
*/
public class FunctionLibraryList implements FunctionLibrary {
public List<FunctionLibrary> libraryList = new ArrayList(8);
public FunctionLibraryList() {}
/**
* Add a new FunctionLibrary to the list of FunctionLibraries in this FunctionLibraryList. Note
* that libraries are searched in the order they are added to the list.
* @param lib A function library to be added to the list of function libraries to be searched.
* @return the position of the library in the list
*/
public int addFunctionLibrary(FunctionLibrary lib) {
libraryList.add(lib);
return libraryList.size() - 1;
}
/**
* Get the n'th function library in the list
*/
public FunctionLibrary get(int n) {
return libraryList.get(n);
}
/**
* 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.
* @param functionName the name of the function
* @param arity The number of arguments. This is set to -1 in the case of the single-argument function-available() function
* @return 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
*/
public boolean hasFunctionSignature(StructuredQName functionName, int arity) {
for (Iterator it=libraryList.iterator(); it.hasNext();) {
FunctionLibrary lib = (FunctionLibrary)it.next();
boolean b = lib.hasFunctionSignature(functionName, arity);
if (b) {
return true;
}
}
return false;
}
/**
* 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.
* @param functionName
* @param staticArgs 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.
* @param env
* @param container
* @return 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 client.net.sf.saxon.ce.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.
*/
public Expression bind(StructuredQName functionName, Expression[] staticArgs, StaticContext env, Container container)
throws XPathException {
for (FunctionLibrary lib : libraryList) {
Expression func = lib.bind(functionName, staticArgs, env, container);
if (func != null) {
return func;
}
}
return null;
}
/**
* Get the list of contained FunctionLibraries. This method allows the caller to modify
* the library list, for example by adding a new FunctionLibrary at a chosen position,
* by removing a library from the list, or by changing the order of libraries in the list.
* Note that such changes may violate rules in the
* language specifications, or assumptions made within the product.
* @return a list whose members are of class FunctionLibrary
*/
public List<FunctionLibrary> getLibraryList() {
return libraryList;
}
}
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is “Incompatible With Secondary Licenses”, as defined by the Mozilla Public License, v. 2.0.