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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.expr;
import net.sf.saxon.om.Item;
import net.sf.saxon.om.SequenceIterator;
import net.sf.saxon.trace.ExpressionPresenter;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.AnyItemType;
import net.sf.saxon.type.ItemType;
import net.sf.saxon.type.TypeHierarchy;
/**
* Error expression: this expression is generated when the supplied expression cannot be
* parsed, and the containing element enables forwards-compatible processing. It defers
* the generation of an error message until an attempt is made to evaluate the expression
*/
public class ErrorExpression extends Expression {
private XPathException exception; // the error found when parsing this expression
/**
* Constructor
* @param exception the error found when parsing this expression
*/
public ErrorExpression(XPathException exception) {
this.exception = exception;
exception.setLocator(this); // to remove any links to the compile-time stylesheet objects
};
/**
* Get the wrapped exception
*/
public XPathException getException() {
return exception;
}
/**
* Type-check the expression.
*/
public Expression typeCheck(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException {
return this;
}
public Expression optimize(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException {
return this;
}
/**
* Evaluate the expression. This always throws the exception registered when the expression
* was first parsed.
*/
public Item evaluateItem(XPathContext context) throws XPathException {
// copy the exception for thread-safety, because we want to add context information
XPathException err = new XPathException(exception.getMessage());
err.setLocator(this);
err.setErrorCode(exception.getErrorCodeLocalPart());
err.setXPathContext(context);
throw err;
}
/**
* Iterate over the expression. This always throws the exception registered when the expression
* was first parsed.
*/
public SequenceIterator iterate(XPathContext context) throws XPathException {
evaluateItem(context);
return null; // to fool the compiler
}
/**
* Determine the data type of the expression, if possible
* @return Type.ITEM (meaning not known in advance)
* @param th the type hierarchy cache
*/
public ItemType getItemType(TypeHierarchy th) {
return AnyItemType.getInstance();
}
/**
* Determine the static cardinality
*/
public int computeCardinality() {
return StaticProperty.ALLOWS_ZERO_OR_MORE;
// we return a liberal value, so that we never get a type error reported
// statically
}
/**
* Copy an expression. This makes a deep copy.
*
* @return the copy of the original expression
*/
public Expression copy() {
return new ErrorExpression(exception);
}
/**
* Diagnostic print of expression structure. The abstract expression tree
* is written to the supplied output destination.
*/
public void explain(ExpressionPresenter destination) {
destination.startElement("error");
destination.emitAttribute("message", exception.getMessage());
destination.endElement();
}
}
//
// 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.
//
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