package net.sf.saxon.functions;
import net.sf.saxon.Configuration;
import net.sf.saxon.expr.CastExpression;
import net.sf.saxon.expr.Expression;
import net.sf.saxon.expr.StaticContext;
import net.sf.saxon.expr.StaticProperty;
import net.sf.saxon.om.NamespaceConstant;
import net.sf.saxon.om.StandardNames;
import net.sf.saxon.om.StructuredQName;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.AtomicType;
import net.sf.saxon.type.SchemaType;
import net.sf.saxon.type.Type;
import net.sf.saxon.value.SequenceType;
/**
* The ConstructorFunctionLibrary represents the collection of constructor functions for atomic types. These
* are provided for the built-in types such as xs:integer and xs:date, and also for user-defined atomic types.
*/
public class ConstructorFunctionLibrary implements FunctionLibrary {
private Configuration config;
/**
* Create a SystemFunctionLibrary
* @param config the Configuration
*/
public ConstructorFunctionLibrary(Configuration config) {
this.config = config;
}
/**
* 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
* @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 SequenceType[] getFunctionSignature(StructuredQName functionName, int arity) {
if (arity != 1 && arity != -1) {
return null;
}
String uri = functionName.getNamespaceURI();
String local = functionName.getLocalName();
if (uri.equals(NamespaceConstant.SCHEMA)) {
AtomicType type = (AtomicType)Type.getBuiltInItemType(uri, local);
if (type != null && type.getFingerprint() != StandardNames.XS_NOTATION) {
return new SequenceType[] {
SequenceType.makeSequenceType(type, StaticProperty.ALLOWS_ZERO_OR_ONE),
SequenceType.OPTIONAL_ATOMIC
};
} else {
return null;
}
}
int fingerprint = config.getNamePool().getFingerprint(uri, local);
if (fingerprint == -1) {
return null;
} else {
SchemaType st = config.getSchemaType(fingerprint);
if (st != null && st.isAtomicType()) {
return new SequenceType[] {
SequenceType.makeSequenceType((AtomicType)st, StaticProperty.ALLOWS_ZERO_OR_ONE),
SequenceType.OPTIONAL_ATOMIC
};
} else {
return null;
}
}
}
/**
* 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 arguments 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[] arguments, StaticContext env)
throws XPathException {
final String uri = functionName.getNamespaceURI();
final String localName = functionName.getLocalName();
String targetURI = uri;
boolean builtInNamespace = uri.equals(NamespaceConstant.SCHEMA);
if (builtInNamespace) {
// it's a constructor function: treat it as shorthand for a cast expression
if (arguments.length != 1) {
throw new XPathException("A constructor function must have exactly one argument");
}
AtomicType type = (AtomicType)Type.getBuiltInItemType(targetURI, localName);
if (type==null || type.getFingerprint() == StandardNames.XS_ANY_ATOMIC_TYPE ||
type.getFingerprint() == StandardNames.XS_NOTATION) {
XPathException err = new XPathException("Unknown constructor function: {" + uri + '}' + localName);
err.setErrorCode("XPST0017");
err.setIsStaticError(true);
throw err;
}
return new CastExpression(arguments[0], type, true);
}
// Now see if it's a constructor function for a user-defined type
if (arguments.length == 1) {
int fp = config.getNamePool().getFingerprint(uri, localName);
if (fp != -1) {
SchemaType st = config.getSchemaType(fp);
if (st != null && st.isAtomicType()) {
return new CastExpression(arguments[0], (AtomicType)st, true);
}
}
}
return null;
}
/**
* 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.
//