package client.net.sf.saxon.ce.functions;
import client.net.sf.saxon.ce.expr.*;
import client.net.sf.saxon.ce.lib.NamespaceConstant;
import client.net.sf.saxon.ce.om.StructuredQName;
import client.net.sf.saxon.ce.trans.Err;
import client.net.sf.saxon.ce.trans.XPathException;
import client.net.sf.saxon.ce.value.AnyURIValue;
import client.net.sf.saxon.ce.value.BooleanValue;
import client.net.sf.saxon.ce.value.EmptySequence;
import java.util.HashMap;
/**
* 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;
private static HashMap<Integer, SystemFunctionLibrary> THE_INSTANCES =
new HashMap<Integer, SystemFunctionLibrary>(3);
/**
* Factory method to create or get a SystemFunctionLibrary
* @param functionSet determines the set of functions allowed. One or more of the bit settings
* {@link StandardFunction#CORE}, {@link StandardFunction#XSLT}, etc
* @return the appropriate SystemFunctionLibrary
*/
public static SystemFunctionLibrary getSystemFunctionLibrary(int functionSet) {
if (THE_INSTANCES.get(functionSet) == null) {
THE_INSTANCES.put(functionSet, new SystemFunctionLibrary(functionSet));
}
return THE_INSTANCES.get(functionSet);
}
/**
* Create a SystemFunctionLibrary
* @param functionSet determines the set of functions allowed. One or more of the bit settings
* {@link StandardFunction#CORE}, {@link StandardFunction#XSLT}, etc
*/
private SystemFunctionLibrary(int functionSet) {
this.functionSet = functionSet;
}
/**
* Test whether a function with a given name and arity is available; if so, return its signature.
* This supports the function-available() function in XSLT; it is also used to support
* higher-order functions introduced in XQuery 1.1.
*
* <p>This method may be called either at compile time
* or at run time. If the function library is to be used only in an XQuery or free-standing XPath
* environment, this method may throw an UnsupportedOperationException.</p>
* @param functionName the qualified name of the function being called
* @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 a zero-length array
* if there is some
* function of this name available for calling.
* @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; or a zero-length
* array if the function exists but the signature is not known; or null if the function does not exist
*/
public boolean hasFunctionSignature(StructuredQName functionName, int arity) {
String uri = functionName.getNamespaceURI();
String local = functionName.getLocalName();
if (uri.equals(NamespaceConstant.FN)) {
StandardFunction.Entry entry = StandardFunction.getFunction(local, arity);
return entry != null &&
((functionSet & entry.applicability) != 0) &&
(arity == -1 ||
(arity >= entry.minArguments && arity <= entry.maxArguments));
} else {
return false;
}
}
/**
* Bind a 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
* @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; 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, Container container)
throws XPathException {
String uri = functionName.getNamespaceURI();
if (uri.equals(NamespaceConstant.FN)) {
String local = functionName.getLocalName();
StandardFunction.Entry entry = StandardFunction.getFunction(local, staticArgs.length);
if (entry != null && entry.minArguments == 1 && staticArgs.length == 0 &&
("name".equals(local) || "local-name".equals(local) || "namespace-uri".equals(local) ||
"generate-id".equals(local) || "string".equals(local) || "number".equals(local) ||
"base-uri".equals(local))) {
Expression[] newArgs = new Expression[]{new ContextItemExpression()};
return bind(functionName, newArgs, env, container);
}
if (entry == null) {
// Functions that can be evaluated or simplified immediately...
if ("true".equals(local) && staticArgs.length == 0) {
return new Literal(BooleanValue.TRUE);
} else if ("false".equals(local) && staticArgs.length == 0) {
return new Literal(BooleanValue.FALSE);
} else if ("collection".equals(local) && staticArgs.length <= 1) {
if (staticArgs.length == 0) {
return new Literal(EmptySequence.getInstance());
} else {
return new ErrorExpression(
new XPathException("No collection URIs are recognized by Saxon-CE", "FODC0002"));
}
} else if ("data".equals(local) && staticArgs.length == 1) {
return new Atomizer(staticArgs[0]);
} else if ("default-collation".equals(local) && staticArgs.length == 0) {
return new StringLiteral(env.getDefaultCollationName());
} else if ("exactly-one".equals(local) && staticArgs.length == 1) {
RoleLocator role = new RoleLocator(RoleLocator.FUNCTION, "one-or-more", 1);
role.setErrorCode("FORG0005");
return CardinalityChecker.makeCardinalityChecker(staticArgs[0], StaticProperty.EXACTLY_ONE, role);
} else if ("idref".equals(local) && (staticArgs.length == 1 || staticArgs.length == 2)) {
return new Literal(EmptySequence.getInstance());
} else if ("nilled".equals(local) && staticArgs.length == 1) {
return new Literal(BooleanValue.FALSE);
} else if ("one-or-more".equals(local) && staticArgs.length == 1) {
RoleLocator role = new RoleLocator(RoleLocator.FUNCTION, "one-or-more", 1);
role.setErrorCode("FORG0004");
return CardinalityChecker.makeCardinalityChecker(staticArgs[0], StaticProperty.ALLOWS_ONE_OR_MORE, role);
} else if ("static-base-uri".equals(local) && staticArgs.length == 0) {
String baseURI = env.getBaseURI();
return (baseURI == null ? Literal.makeEmptySequence() : new Literal(new AnyURIValue(baseURI)));
} else if ("trace".equals(local) && staticArgs.length == 2) {
return staticArgs[0];
} else if ("unordered".equals(local) && staticArgs.length == 1) {
return staticArgs[0];
} else if ("unparsed-entity-uri".equals(local) && staticArgs.length == 1) {
return new StringLiteral("");
} else if ("unparsed-entity-public-id".equals(local) && staticArgs.length == 1) {
return new StringLiteral("");
} else if ("zero-or-one".equals(local) && staticArgs.length == 1) {
RoleLocator role = new RoleLocator(RoleLocator.FUNCTION, "zero-or-one", 1);
role.setErrorCode("FORG0003");
return CardinalityChecker.makeCardinalityChecker(staticArgs[0], StaticProperty.ALLOWS_ZERO_OR_ONE, role);
} else 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 + "#"+staticArgs.length +" cannot be called with "
+ pluralArguments(staticArgs.length));
err.setErrorCode("XPST0017");
err.setIsStaticError(true);
throw err;
}
}
if ((functionSet & entry.applicability) == 0) {
XPathException err = new XPathException("System function " + local + "#"+staticArgs.length +" is not available with this host language");
err.setErrorCode("XPST0017");
err.setIsStaticError(true);
throw err;
}
SystemFunction f = entry.skeleton.newInstance();
f.setDetails(entry);
f.setFunctionName(functionName);
f.setArguments(staticArgs);
f.setContainer(container);
checkArgumentCount(staticArgs.length, entry.minArguments, entry.maxArguments, local);
return f;
} else {
return null;
}
}
/**
* Check number of arguments. <BR>
* 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 client.net.sf.saxon.ce.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 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.