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eXist-db NoSQL Database Core
/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-2010 The eXist Project
* http://exist-db.org
*
* 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* $Id$
*/
package org.exist.xquery;
import org.exist.dom.persistent.DocumentSet;
import org.exist.dom.QName;
import org.exist.dom.memtree.NodeImpl;
import org.exist.xquery.util.Error;
import org.exist.xquery.util.Messages;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceIterator;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
import org.exist.xquery.value.ValueSequence;
/**
* An XQuery/XPath variable, consisting of a QName and a value.
*
* @author wolf
*/
public class VariableImpl implements Variable {
// the name of the variable
private final QName qname;
// the current value assigned to the variable
private Sequence value = null;
// the context position of this variable in the local variable stack
// this can be used to determine if a variable has been declared
// before another
private int positionInStack = 0;
// the context document set
private DocumentSet contextDocs = null;
// the sequence type of this variable if known
private SequenceType type = null;
private int staticType = Type.ITEM;
private boolean initialized = true;
public VariableImpl(QName qname) {
this.qname = qname;
}
public VariableImpl(VariableImpl var) {
this(var.qname);
this.value = var.value;
this.contextDocs = var.contextDocs;
this.type = var.type;
this.staticType = var.staticType;
}
public void setValue(Sequence val) {
this.value = val;
if (val instanceof NodeImpl) {
ValueSequence newSeq = new ValueSequence(1);
newSeq.add((Item) val);
newSeq.setHolderVariable(this);
this.value = newSeq;
} else if (val instanceof ValueSequence) {
((ValueSequence) this.value).setHolderVariable(this);
}
}
public Sequence getValue() {
return value;
}
public QName getQName() {
return qname;
}
public int getType() {
if(type != null)
{return type.getPrimaryType();}
else
{return Type.ITEM;}
}
public void setSequenceType(SequenceType type) throws XPathException {
this.type = type;
//Check the value's type if it is already assigned : happens with external variables
if (getValue() != null) {
if (getSequenceType() != null) {
int actualCardinality;
if (getValue().isEmpty()) {actualCardinality = Cardinality.EMPTY;}
else if (getValue().hasMany()) {actualCardinality = Cardinality.MANY;}
else {actualCardinality = Cardinality.ONE;}
//Type.EMPTY is *not* a subtype of other types ; checking cardinality first
if (!Cardinality.checkCardinality(getSequenceType().getCardinality(), actualCardinality))
{throw new XPathException("XPTY0004: Invalid cardinality for variable $" + getQName() +
". Expected " +
Cardinality.getDescription(getSequenceType().getCardinality()) +
", got " + Cardinality.getDescription(actualCardinality));}
//TODO : ignore nodes right now ; they are returned as xs:untypedAtomicType
if (!Type.subTypeOf(getSequenceType().getPrimaryType(), Type.NODE)) {
if (!getValue().isEmpty() && !Type.subTypeOf(getValue().getItemType(), getSequenceType().getPrimaryType()))
{throw new XPathException("XPTY0004: Invalid type for variable $" + getQName() +
". Expected " +
Type.getTypeName(getSequenceType().getPrimaryType()) +
", got " +Type.getTypeName(getValue().getItemType()));}
//Here is an attempt to process the nodes correctly
} else {
//Same as above : we probably may factorize
if (!getValue().isEmpty() && !Type.subTypeOf(getValue().getItemType(), getSequenceType().getPrimaryType()))
{throw new XPathException("XPTY0004: Invalid type for variable $" + getQName() +
". Expected " +
Type.getTypeName(getSequenceType().getPrimaryType()) +
", got " +Type.getTypeName(getValue().getItemType()));}
}
}
}
}
public SequenceType getSequenceType() {
return type;
}
public void setStaticType(int type) {
staticType = type;
}
public int getStaticType() {
return staticType;
}
public boolean isInitialized() {
return initialized;
}
public void setIsInitialized(boolean initialized) {
this.initialized = initialized;
}
public void destroy(XQueryContext context, Sequence contextSequence) {
if (value != null)
{value.destroy(context, contextSequence);}
}
public String toString() {
final StringBuilder result = new StringBuilder();
result.append("$").append(qname.getStringValue());
result.append(" as ");
result.append(Type.getTypeName(getType()));
result.append(Cardinality.toString(getCardinality()));
result.append(" ");
if (value == null)
{result.append("[not set]");}
else
{result.append(":= ").append(value.toString());}
return result.toString();
}
public int getDependencies(XQueryContext context) {
// if(context.getCurrentStackSize() > positionInStack)
// return Dependency.CONTEXT_SET + Dependency.GLOBAL_VARS+ Dependency.CONTEXT_ITEM;
// else
// return Dependency.CONTEXT_SET + Dependency.LOCAL_VARS;
if(context.getCurrentStackSize() > positionInStack)
{return Dependency.CONTEXT_SET + Dependency.CONTEXT_VARS;}
else
{return Dependency.CONTEXT_SET + Dependency.LOCAL_VARS;}
}
public int getCardinality() {
return Cardinality.ZERO_OR_MORE;
}
public void setStackPosition(int position) {
positionInStack = position;
}
public DocumentSet getContextDocs() {
return contextDocs;
}
public void setContextDocs(DocumentSet docs) {
this.contextDocs = docs;
}
public void checkType() throws XPathException {
if (type == null)
{return;}
type.checkCardinality(value);
if (value.isEmpty())
{return;}
final int requiredType = type.getPrimaryType();
if(Type.subTypeOf(requiredType, Type.ATOMIC)) {
if(!Type.subTypeOf(value.getItemType(), Type.ATOMIC))
{value = Atomize.atomize(value);}
//TODO : we should recheck the dependencies of this method
//and remove that conversion !
if(requiredType != Type.ATOMIC)
{value = convert(value);}
}
if(!type.checkType(value))
{throw new XPathException( Messages.getMessage( Error.VAR_TYPE_MISMATCH,
toString(),
type.toString(),
new SequenceType(value.getItemType(), value.getCardinality()).toString()
)
);}
}
private Sequence convert(Sequence seq) throws XPathException {
final ValueSequence result = new ValueSequence();
Item item;
for(final SequenceIterator i = seq.iterate(); i.hasNext(); ) {
item = i.nextItem();
result.add(item.convertTo(type.getPrimaryType()));
}
return result;
}
}
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