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Provides a basic XSLT 2.0 and XQuery 1.0 processor (W3C Recommendations,
January 2007). Command line interfaces and implementations of several
Java APIs (DOM, XPath, s9api) are also included.
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package net.sf.saxon.functions;
import net.sf.saxon.Err;
import net.sf.saxon.expr.Expression;
import net.sf.saxon.expr.StaticContext;
import net.sf.saxon.om.NamespaceConstant;
import net.sf.saxon.om.StructuredQName;
import net.sf.saxon.trans.XPathException;
/**
* The SystemFunctionLibrary represents the collection of functions in the fn: namespace. That is, the
* functions defined in the "Functions and Operators" specification, optionally augmented by the additional
* functions defined in XSLT.
*/
public class SystemFunctionLibrary implements FunctionLibrary {
private int functionSet;
public static final int XPATH_ONLY = 0;
public static final int FULL_XSLT = 1;
public static final int USE_WHEN = 2;
private static SystemFunctionLibrary[] THE_INSTANCES = new SystemFunctionLibrary[3];
/**
* Factory method to create or get a SystemFunctionLibrary
* @param functionSet determines the set of functions allowed. One of
* {@link #XPATH_ONLY}, {@link #FULL_XSLT}, {@link #USE_WHEN}
* @return the appropriate SystemFunctionLibrary
*/
public static SystemFunctionLibrary getSystemFunctionLibrary(int functionSet) {
if (THE_INSTANCES[functionSet] == null) {
THE_INSTANCES[functionSet] = new SystemFunctionLibrary(functionSet);
}
return THE_INSTANCES[functionSet];
}
/**
* Create a SystemFunctionLibrary
* @param functionSet determines the set of functions allowed. One of
* {@link #XPATH_ONLY}, {@link #FULL_XSLT}, {@link #USE_WHEN}
*/
private SystemFunctionLibrary(int functionSet) {
this.functionSet = functionSet;
}
/**
* Test whether a system 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.
* @param functionName the name of the function being tested
* @param arity 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
*/
public boolean isAvailable(StructuredQName functionName, int arity) {
String uri = functionName.getNamespaceURI();
String local = functionName.getLocalName();
if (uri.equals(NamespaceConstant.FN)) {
StandardFunction.Entry entry = StandardFunction.getFunction(local, arity);
if (entry == null) {
return false;
}
if (!(arity == -1 || (arity >= entry.minArguments && arity <= entry.maxArguments))) {
return false;
}
//noinspection RedundantIfStatement
if (functionSet == USE_WHEN && (
local.equals("current") ||
local.equals("current-group") ||
local.equals("current-grouping-key") ||
local.equals("document") ||
local.equals("format-date") ||
local.equals("format-dateTime") ||
local.equals("format-time") ||
local.equals("generate-id") ||
local.equals("key") ||
local.equals("regex-group") ||
local.equals("unparsed-entity-uri") ||
local.equals("unparsed-entity-public-id") ||
local.equals("unparsed-text"))) {
return false;
}
return true;
} else {
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 the name of the function to be bound
* @param staticArgs 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.
* @param env
* @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 net.sf.saxon.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; or if this function library "owns" the namespace containing
* the function call, but no function was found.
*/
public Expression bind(StructuredQName functionName, Expression[] staticArgs, StaticContext env)
throws XPathException {
String uri = functionName.getNamespaceURI();
String local = functionName.getLocalName();
if (uri.equals(NamespaceConstant.FN)) {
StandardFunction.Entry entry = StandardFunction.getFunction(local, staticArgs.length);
if (entry == null) {
if (StandardFunction.getFunction(local, -1) == null) {
XPathException err = new XPathException("Unknown system function " + local + "()");
err.setErrorCode("XPST0017");
err.setIsStaticError(true);
throw err;
} else {
XPathException err = new XPathException("System function " + local + "() cannot be called with "
+ pluralArguments(staticArgs.length));
err.setErrorCode("XPST0017");
err.setIsStaticError(true);
throw err;
}
}
Class functionClass = entry.implementationClass;
SystemFunction f;
try {
f = (SystemFunction)functionClass.newInstance();
} catch (Exception err) {
throw new AssertionError("Failed to load system function: " + err.getMessage());
}
f.setDetails(entry);
f.setFunctionName(functionName);
if (functionSet != FULL_XSLT) {
if (f instanceof XSLTFunction || (f instanceof NamePart && entry.opcode==NamePart.GENERATE_ID)) {
if (functionSet == XPATH_ONLY) {
XPathException err = new XPathException("Cannot use the " + local + "() function in a non-XSLT context");
err.setErrorCode("XPST0017");
err.setIsStaticError(true);
throw err;
} else if (functionSet == USE_WHEN &&
!(f instanceof Available || f instanceof SystemProperty)) {
XPathException err = new XPathException("Cannot use the " + local + "() function in a use-when expression");
err.setErrorCode("XPST0017");
err.setIsStaticError(true);
throw err;
}
}
}
f.setArguments(staticArgs);
checkArgumentCount(staticArgs.length, entry.minArguments, entry.maxArguments, local);
return f;
} else {
return null;
}
}
/**
* Check number of arguments.
* A convenience routine for use in subclasses.
* @param numArgs the actual number of arguments (arity)
* @param min the minimum number of arguments allowed
* @param max the maximum number of arguments allowed
* @param local the local name of the function (for diagnostics)
* @return the actual number of arguments
* @throws net.sf.saxon.trans.XPathException if the number of arguments is out of range
*/
private int checkArgumentCount(int numArgs, int min, int max, String local) throws XPathException {
if (min==max && numArgs != min) {
throw new XPathException("Function " + Err.wrap(local, Err.FUNCTION) + " must have "
+ min + pluralArguments(min));
}
if (numArgs < min) {
throw new XPathException("Function " + Err.wrap(local, Err.FUNCTION) + " must have at least "
+ min + pluralArguments(min));
}
if (numArgs > max) {
throw new XPathException("Function " + Err.wrap(local, Err.FUNCTION) + " must have no more than "
+ max + pluralArguments(max));
}
return numArgs;
}
/**
* Utility routine used in constructing error messages
* @param num the number of arguments
* @return the string " argument" or "arguments" depending whether num is plural
*/
private static String pluralArguments(int num) {
if (num==1) return " argument";
return " arguments";
}
/**
* 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.
*
* @return a copy of this function library. This must be an instance of the original class.
*/
public FunctionLibrary copy() {
return this;
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay.
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//© 2015 - 2025 Weber Informatics LLC | Privacy Policy