/*
* @(#)$Id: RecursiveCall.java 3619 2008-03-26 07:23:03Z yui $
*
* Copyright 2006-2008 Makoto YUI
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Contributors:
* Makoto YUI - initial implementation
*/
package xbird.xquery.expr.func;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import xbird.xquery.XQueryException;
import xbird.xquery.dm.value.Item;
import xbird.xquery.dm.value.Sequence;
import xbird.xquery.dm.value.sequence.ValueSequence;
import xbird.xquery.expr.XQExpression;
import xbird.xquery.expr.var.BindingVariable.ParametricVariable;
import xbird.xquery.func.UserFunction;
import xbird.xquery.meta.DynamicContext;
import xbird.xquery.meta.XQueryContext;
import xbird.xquery.misc.QNameUtil;
import xbird.xquery.parser.XQueryParserVisitor;
/**
*
* <DIV lang="en"></DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
*/
public class RecursiveCall extends DirectFunctionCall {
private static final long serialVersionUID = -9206675238870249718L;
private static final Log LOG = LogFactory.getLog(LazyFunctionCall.class);
public RecursiveCall(UserFunction func, List<XQExpression> params) {
super(func, params);
this._type = func.getReturnType();
assert (_type != null);
}
public RecursiveCall() {// for Externalizable
super();
}
@Override
public XQExpression visit(XQueryParserVisitor visitor, XQueryContext ctxt)
throws XQueryException {
return visitor.visit(this, ctxt);
}
@Override
public UserFunction getFunction() {
return (UserFunction) func;
}
@Override
public Sequence<? extends Item> eval(Sequence<? extends Item> contextSeq, DynamicContext dynEnv)
throws XQueryException {
UserFunction uf = this.getFunction();
List<ParametricVariable> params = uf.getParameters();
int paramArity = _params.size();
int argArity = params.size();
assert (paramArity == argArity);
FunctionCallContext recEnv = new FunctionCallContext(dynEnv);
for(int i = 0; i < paramArity; i++) {
ParametricVariable paramVar = params.get(i);
XQExpression argExpr = _params.get(i);
Sequence argValue = argExpr.eval(contextSeq, dynEnv);
paramVar.allocateResult(argValue, recEnv);
}
Sequence<? extends Item> result = uf.eval(contextSeq, ValueSequence.EMPTY_SEQUENCE, recEnv);
if(LOG.isDebugEnabled()) {
LOG.debug("Invoke RecursiveCall: " + QNameUtil.toLexicalForm(getFuncName()));
}
return result;
}
}