/*
* @(#)$Id: NegativeExpr.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.math;
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.AbstractXQExpression;
import xbird.xquery.expr.XQExpression;
import xbird.xquery.meta.*;
import xbird.xquery.operator.OverloadedFunction;
import xbird.xquery.operator.math.UnaryMinus;
import xbird.xquery.parser.XQueryParserVisitor;
/**
*
* <DIV lang="en"></DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
*/
public final class NegativeExpr extends AbstractXQExpression {
private static final long serialVersionUID = -2769785866970377773L;
private XQExpression _expr;
private OverloadedFunction _op = null;
public NegativeExpr(XQExpression expr) {
this._expr = expr;
}
public XQExpression getExpression() {
return _expr;
}
public XQExpression visit(XQueryParserVisitor visitor, XQueryContext ctxt)
throws XQueryException {
return visitor.visit(this, ctxt);
}
public XQExpression staticAnalysis(StaticContext statEnv) throws XQueryException {
if(!_analyzed) {
this._analyzed = true;
this._expr = _expr.staticAnalysis(statEnv);
final UnaryMinus op = new UnaryMinus();
op.staticAnalysis(statEnv, _expr);
this._op = op;
this._type = op.getReturnType();
}
return this;
}
public Sequence<? extends Item> eval(Sequence<? extends Item> contextSeq, DynamicContext dynEnv)
throws XQueryException {
final Item v1 = _expr.evalAsItem(contextSeq, dynEnv, true);
if(v1 == null) {
return ValueSequence.EMPTY_SEQUENCE;
}
Sequence res = _op.eval(dynEnv, v1);
return res;
}
}