/*
// $Id: //open/mondrian-release/3.2/src/main/mondrian/olap/fun/IsNullFunDef.java#1 $
// This software is subject to the terms of the Eclipse Public License v1.0
// Agreement, available at the following URL:
// http://www.eclipse.org/legal/epl-v10.html.
// Copyright (C) 2006-2006 Julian Hyde
// All Rights Reserved.
// You must accept the terms of that agreement to use this software.
*/
package mondrian.olap.fun;
import mondrian.calc.Calc;
import mondrian.calc.ExpCompiler;
import mondrian.calc.MemberCalc;
import mondrian.calc.impl.AbstractBooleanCalc;
import mondrian.mdx.ResolvedFunCall;
import mondrian.olap.Evaluator;
import mondrian.olap.FunDef;
import mondrian.olap.Member;
import mondrian.olap.Literal;
/**
* Definition of the <code>IS NULL</code> MDX function.
*
* @author medstat
* @version $Id: //open/mondrian-release/3.2/src/main/mondrian/olap/fun/IsNullFunDef.java#1 $
* @since Aug 21, 2006
*/
class IsNullFunDef extends FunDefBase {
/**
* Resolves calls to the <code>IS NULL</code> postfix operator.
*/
static final ReflectiveMultiResolver Resolver = new ReflectiveMultiResolver(
"IS NULL",
"<Expression> IS NULL",
"Returns whether an object is null",
new String[]{"Qbm", "Qbl", "Qbh", "Qbd"},
IsNullFunDef.class);
public IsNullFunDef(FunDef dummyFunDef) {
super(dummyFunDef);
}
public Calc compileCall(ResolvedFunCall call, ExpCompiler compiler) {
assert call.getArgCount() == 1;
final MemberCalc memberCalc = compiler.compileMember(call.getArg(0));
return new AbstractBooleanCalc(call, new Calc[]{memberCalc}) {
public boolean evaluateBoolean(Evaluator evaluator) {
Member member = memberCalc.evaluateMember(evaluator);
return member.isNull();
}
};
}
}
// End IsNullFunDef.java