org.exist.xquery.VariableDeclaration Maven / Gradle / Ivy
/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-06 Wolfgang M. Meier
* [email protected]
* 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.QName;
import org.exist.xquery.util.ExpressionDumper;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
import java.util.Optional;
/**
* A global variable declaration (with: declare variable). Variable bindings within
* for and let expressions are handled by {@link org.exist.xquery.ForExpr} and
* {@link org.exist.xquery.LetExpr}.
*
* @author wolf
*/
public class VariableDeclaration extends AbstractExpression implements RewritableExpression {
final QName qname;
Optional expression;
SequenceType sequenceType = null;
boolean analyzeDone = false;
public VariableDeclaration(XQueryContext context, QName qname, Expression expr) {
super(context);
this.qname = qname;
this.expression = Optional.ofNullable(expr);
}
public QName getName() {
return qname;
}
/**
* Set the sequence type of the variable.
*
* @param type the sequence type
*/
public void setSequenceType(SequenceType type) {
this.sequenceType = type;
}
public SequenceType getSequenceType() {
return sequenceType;
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#analyze(org.exist.xquery.AnalyzeContextInfo)
*/
public void analyze(AnalyzeContextInfo contextInfo) throws XPathException {
contextInfo.setParent(this);
final Variable var = new VariableImpl(qname);
var.setIsInitialized(false);
if (!analyzeDone) {
final Module myModule = context.getModule(qname.getNamespaceURI());
if(myModule != null) {
// WM: duplicate var declaration is now caught in the XQuery tree parser
// if (myModule.isVarDeclared(qn))
// throw new XPathException(this, ErrorCodes.XQST0049, "It is a static error if more than one " +
// "variable declared or imported by a module has the same expanded QName. Variable: " + qn);
myModule.declareVariable(var);
} else {
// WM: duplicate var declaration is now caught in the XQuery tree parser
// if(context.isVarDeclared(qn)) {
// throw new XPathException(this, ErrorCodes.XQST0049, "It is a static error if more than one " +
// "variable declared or imported by a module has the same expanded QName. Variable: " + qn);
// }
context.declareGlobalVariable(var);
}
analyzeDone = true;
}
analyzeExpression(contextInfo);
var.setIsInitialized(true);
}
/**
* Analyze just the expression. For dynamically imported modules this needs to be done one time
* after import.
*
* @param contextInfo context information
* @throws XPathException in case of static error
*/
public void analyzeExpression(AnalyzeContextInfo contextInfo) throws XPathException {
if (expression.isPresent()) {
expression.get().analyze(contextInfo);
}
}
@Override
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);}
}
context.pushInScopeNamespaces(false);
try {
final Module myModule = context.getRootModule(qname.getNamespaceURI());
context.pushDocumentContext();
try {
context.prologEnter(this);
if (expression.isPresent()) {
// normal variable declaration or external var with default value
final Sequence seq = expression.get().eval(contextSequence, null);
final Variable var;
if (myModule != null) {
var = myModule.declareVariable(qname, seq);
var.setSequenceType(sequenceType);
var.checkType();
} else {
var = new VariableImpl(qname);
var.setValue(seq);
var.setSequenceType(sequenceType);
var.checkType();
context.declareGlobalVariable(var);
}
if (context.getProfiler().isEnabled()) {
//Note : that we use seq but we return Sequence.EMPTY_SEQUENCE
context.getProfiler().end(this, "", seq);
}
} else {
// external variable without default
final Variable external = context.resolveGlobalVariable(qname);
if (external == null) {
// If no value is provided for the variable by the external environment, and VarDefaultValue
// is not specified, then a dynamic error is raised [err:XPDY0002]
throw new XPathException(ErrorCodes.XPDY0002, "no value specified for external variable " +
qname);
}
external.setSequenceType(sequenceType);
if (myModule != null) {
// declare on module
myModule.declareVariable(external);
}
}
} finally {
context.popDocumentContext();
}
} finally {
context.popInScopeNamespaces();
}
return null;
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#dump(org.exist.xquery.util.ExpressionDumper)
*/
public void dump(ExpressionDumper dumper) {
dumper.nl().display("declare variable $").display(qname.toString(), line);
if(sequenceType != null) {
dumper.display(" as ").display(sequenceType.toString());
}
dumper.display("{");
dumper.startIndent();
expression.ifPresent(e -> e.dump(dumper));
dumper.endIndent();
dumper.nl().display("}").nl();
}
public String toString() {
final StringBuilder result = new StringBuilder();
result.append("declare variable $").append(qname);
if(sequenceType != null) {
result.append(" as ").append(sequenceType.toString());
}
if (expression.isPresent()) {
result.append("{");
result.append(expression.toString());
result.append("}");
}
return result.toString();
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#returnsType()
*/
public int returnsType() {
return expression.isPresent() ? expression.get().returnsType() : Type.ITEM;
}
/* (non-Javadoc)
* @see org.exist.xquery.AbstractExpression#getDependencies()
*/
public int getDependencies() {
return Dependency.CONTEXT_SET;
}
/* (non-Javadoc)
* @see org.exist.xquery.AbstractExpression#getCardinality()
*/
public int getCardinality() {
return expression.isPresent() ? expression.get().getCardinality() : Cardinality.ONE_OR_MORE;
}
public Optional getExpression() {
return expression;
}
/* RewritableExpression API */
public void replace(Expression oldExpr, Expression newExpr) {
if (expression.isPresent() && expression.get() == oldExpr) {
this.expression = Optional.ofNullable(newExpr);
}
}
@Override
public Expression getPrevious(Expression current) {
return null;
}
@Override
public Expression getFirst() {
return null;
}
@Override
public void remove(Expression oldExpr) throws XPathException {
}
/* END RewritableExpression API */
@Override
public boolean allowMixedNodesInReturn() {
return true;
}
@Override
public void accept(ExpressionVisitor visitor) {
visitor.visitVariableDeclaration(this);
}
/* (non-Javadoc)
* @see org.exist.xquery.AbstractExpression#resetState()
*/
public void resetState(boolean postOptimization) {
super.resetState(postOptimization);
expression.ifPresent(e -> e.resetState(postOptimization));
if (!postOptimization)
{analyzeDone = false;}
}
}
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