/*
* @(#)$Id: AdditiveExpr.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.Evaluable;
import xbird.xquery.expr.XQExpression;
import xbird.xquery.expr.var.Variable.PreEvaluatedVariable;
import xbird.xquery.meta.*;
import xbird.xquery.operator.OverloadedFunction;
import xbird.xquery.operator.math.MinusOp;
import xbird.xquery.operator.math.PlusOp;
import xbird.xquery.parser.XQueryParserVisitor;
/**
*
* <DIV lang="en"></DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
* @link http://www.w3.org/TR/xquery/#id-arithmetic
* @link http://www.w3.org/TR/xquery-semantics/#sec_arithmetic
*/
public final class AdditiveExpr extends ArithmeticExpr {
private static final long serialVersionUID = 819347526645410348L;
private final boolean isPlusOp;
private OverloadedFunction _op = null;
public AdditiveExpr(boolean isPlusOp, XQExpression leftOperand, XQExpression rightOperand) {
super(leftOperand, rightOperand);
this.isPlusOp = isPlusOp;
}
public XQExpression visit(XQueryParserVisitor visitor, XQueryContext ctxt)
throws XQueryException {
return visitor.visit(this, ctxt);
}
public boolean isPlus() {
return this.isPlusOp;
}
@Override
public XQExpression staticAnalysis(StaticContext statEnv) throws XQueryException {
super.staticAnalysis(statEnv);
final OverloadedFunction op = resolveOp();
op.staticAnalysis(statEnv, _leftOperand, _rightOperand);
this._op = op;
if(_leftOperand instanceof Evaluable && _rightOperand instanceof Evaluable) {
// apply eagar evaluation
final Sequence<? extends Item> evaluated = eval(null, DynamicContext.DUMMY);
return new PreEvaluatedVariable(evaluated);
}
this._type = op.getReturnType();
return this;
}
public Sequence<? extends Item> eval(Sequence<? extends Item> contextSeq, DynamicContext dynEnv)
throws XQueryException {
final Item v1 = _leftOperand.evalAsItem(contextSeq, dynEnv, true);
if(v1 == null) {
return ValueSequence.EMPTY_SEQUENCE;
}
final Item v2 = _rightOperand.evalAsItem(contextSeq, dynEnv, true);
if(v2 == null) {
return ValueSequence.EMPTY_SEQUENCE;
}
Sequence res = _op.eval(dynEnv, v1, v2);
return res;
}
private OverloadedFunction resolveOp() {
if(isPlusOp) {
return new PlusOp();
} else {
return new MinusOp();
}
}
}