/*
* @(#)$Id: QuantifiedExpr.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.cond;
import xbird.xquery.XQueryException;
import xbird.xquery.dm.value.Item;
import xbird.xquery.dm.value.Sequence;
import xbird.xquery.dm.value.xsi.BooleanValue;
import xbird.xquery.expr.*;
import xbird.xquery.expr.var.BindingVariable;
import xbird.xquery.expr.var.BindingVariable.QuantifiedVariable;
import xbird.xquery.expr.var.Variable.PreEvaluatedVariable;
import xbird.xquery.func.seq.FnBoolean;
import xbird.xquery.meta.*;
import xbird.xquery.misc.TypeUtil;
import xbird.xquery.parser.XQueryParserVisitor;
import xbird.xquery.type.SequenceType;
import xbird.xquery.type.xs.BooleanType;
/**
*
* <DIV lang="en"></DIV>
* <DIV lang="ja"></DIV>
*
* @author yui (yuin405+xbird@gmail.com)
* @link http://www.w3.org/TR/xquery/#id-quantified-expressions
* @link http://www.w3.org/TR/xquery-semantics/#id-quantified-expressions
*/
public class QuantifiedExpr extends AbstractXQExpression implements BooleanOp {
private static final long serialVersionUID = 3130103441451724447L;
private final boolean every;
private final QuantifiedVariable bindingVar;
private XQExpression condExpr = null;
public QuantifiedExpr(boolean every, QuantifiedVariable bindingVar) {
assert (bindingVar != null);
this.every = every;
this.bindingVar = bindingVar;
this._type = BooleanType.BOOLEAN;
}
public XQExpression visit(XQueryParserVisitor visitor, XQueryContext ctxt)
throws XQueryException {
return visitor.visit(this, ctxt);
}
public boolean isEvery() {
return this.every;
}
public BindingVariable getBinding() {
return bindingVar;
}
public void setCondExpr(XQExpression cond) {
this.condExpr = cond;
}
public XQExpression getCondExpr() {
return this.condExpr;
}
//--------------------------------------------
// static analysis/dynamic evaluation
public XQExpression staticAnalysis(StaticContext statEnv) throws XQueryException {
if(!_analyzed) {
this._analyzed = true;
final XQExpression analyzed = bindingVar.staticAnalysis(statEnv);
if(analyzed instanceof Evaluable) {
final Sequence<? extends Item> src = analyzed.eval(null, DynamicContext.DUMMY);
final Sequence<? extends Item> evaluated = effectiveBooleanValue(src, null, DynamicContext.DUMMY);
return new PreEvaluatedVariable(evaluated);
} else if(TypeUtil.subtypeOf(SequenceType.EMPTY, bindingVar.getType())) {
final boolean isEvery = every;
return new LiteralExpr(isEvery ? BooleanValue.TRUE : BooleanValue.FALSE);
}
this.condExpr = condExpr.staticAnalysis(statEnv);
}
return this;
}
public Sequence<? extends Item> eval(Sequence<? extends Item> contextSeq, DynamicContext dynEnv)
throws XQueryException {
final XQExpression inExpr = bindingVar.getValue();
final Sequence<? extends Item> src = inExpr.eval(contextSeq, dynEnv);
return effectiveBooleanValue(src, contextSeq, dynEnv);
}
public Sequence<? extends Item> effectiveBooleanValue(Sequence<? extends Item> src, Sequence<? extends Item> contextSeq, DynamicContext dynEnv)
throws XQueryException {
final IFocus<? extends Item> srcItor = src.iterator();
if(every) {
while(true) {
if(!srcItor.hasNext()) {
srcItor.closeQuietly();
return BooleanValue.TRUE;
} else {
final Item curitem = srcItor.next();
bindingVar.allocateResult(curitem, dynEnv);
final Sequence v = condExpr.eval(contextSeq, dynEnv);
if(!FnBoolean.effectiveBooleanValue(v)) {
srcItor.closeQuietly();
return BooleanValue.FALSE;
}
}
}
} else {//some
while(true) {
if(!srcItor.hasNext()) {
srcItor.closeQuietly();
return BooleanValue.FALSE;
} else {
final Item curitem = srcItor.next();
bindingVar.allocateResult(curitem, dynEnv);
final Sequence v = condExpr.eval(contextSeq, dynEnv);
if(FnBoolean.effectiveBooleanValue(v)) {
srcItor.closeQuietly();
return BooleanValue.TRUE;
}
}
}
}
}
}