/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-06 Wolfgang M. Meier
* wolfgang@exist-db.org
* http://exist.sourceforge.net
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id$
*/
package org.exist.xquery;
import org.exist.dom.DocumentSet;
import org.exist.xquery.util.ExpressionDumper;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.Type;
/**
* Represents a reference to an in-scope variable.
*
* @author wolf
*/
public class VariableReference extends AbstractExpression {
private final String qname;
public VariableReference(XQueryContext context, String qname) {
super(context);
this.qname = qname;
}
public String getName() {
return qname;
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#analyze(org.exist.xquery.AnalyzeContextInfo)
*/
public void analyze(AnalyzeContextInfo contextInfo) throws XPathException {
Variable var = null;
try {
var = getVariable();
} catch (final XPathException e) {
// ignore: variable might not be known yet
return;
}
if (var == null)
{throw new XPathException(this, ErrorCodes.XPDY0002,
"variable '$" + qname + "' is not set.");}
if (!var.isInitialized())
{throw new XPathException(this, ErrorCodes.XQST0054,
"variable declaration of '$" + qname + "' cannot " +
"be executed because of a circularity.");}
contextInfo.setStaticReturnType(var.getStaticType());
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#eval(org.exist.xquery.StaticContext, org.exist.dom.DocumentSet, org.exist.xquery.value.Sequence, org.exist.xquery.value.Item)
*/
public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathException {
if (context.getProfiler().isEnabled()) {
context.getProfiler().start(this);
context.getProfiler().message(this, Profiler.DEPENDENCIES,
"DEPENDENCIES", Dependency.getDependenciesName(this.getDependencies()));
if (contextSequence != null)
{context.getProfiler().message(this, Profiler.START_SEQUENCES,
"CONTEXT SEQUENCE", contextSequence);}
if (contextItem != null)
{context.getProfiler().message(this, Profiler.START_SEQUENCES,
"CONTEXT ITEM", contextItem.toSequence());}
}
final Variable var = getVariable();
if (var == null)
{throw new XPathException(this, ErrorCodes.XPDY0002, "variable '$" + qname + "' is not set.");}
final Sequence seq = var.getValue();
if (seq == null)
{throw new XPathException(this, ErrorCodes.XPDY0002, "undefined value for variable '$" + qname + "'");}
final Sequence result = seq;
if (context.getProfiler().isEnabled())
{context.getProfiler().end(this, "", result);}
return result;
}
protected Variable getVariable() throws XPathException {
try {
return context.resolveVariable(qname);
} catch (final XPathException e) {
e.setLocation(line, column);
throw e;
}
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#preselect(org.exist.dom.DocumentSet, org.exist.xquery.StaticContext)
*/
public DocumentSet preselect(DocumentSet in_docs) throws XPathException {
return in_docs;
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#dump(org.exist.xquery.util.ExpressionDumper)
*/
public void dump(ExpressionDumper dumper) {
dumper.display('$').display(qname);
}
public String toString() {
return "$" + qname;
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#returnsType()
*/
public int returnsType() {
try {
final Variable var = context.resolveVariable(qname);
if(var != null) {
if (var.getValue() != null) {
final int type = var.getValue().getItemType();
return type;
} else {
return var.getType();
}
}
} catch (final XPathException e) {
//TODO : don't ignore ? -pb
}
return Type.ITEM;
}
/* (non-Javadoc)
* @see org.exist.xquery.AbstractExpression#getDependencies()
*/
public int getDependencies() {
try {
final Variable var = context.resolveVariable(qname);
if (var != null) {
final int deps = var.getDependencies(context);
return deps;
}
} catch (final XPathException e) {
//TODO : don't ignore ? -pb
}
return Dependency.CONTEXT_SET + Dependency.CONTEXT_ITEM;
}
/* (non-Javadoc)
* @see org.exist.xquery.AbstractExpression#getCardinality()
*/
public int getCardinality() {
try {
final Variable var = context.resolveVariable(qname);
if (var != null && var.getValue() != null) {
final int card = var.getValue().getCardinality();
return card;
}
} catch (final XPathException e) {
//TODO : don't ignore ?
}
return Cardinality.ZERO_OR_MORE; // unknown cardinality
}
/* (non-Javadoc)
* @see org.exist.xquery.AbstractExpression#resetState()
*/
public void resetState(boolean postOptimization) {
super.resetState(postOptimization);
}
public void accept(ExpressionVisitor visitor) {
visitor.visitVariableReference(this);
}
@Override
public boolean allowMixedNodesInReturn() {
return true;
}
}