/*
// $Id: //open/mondrian-release/3.2/src/main/mondrian/olap/fun/UnionFunDef.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) 2006-2009 Julian Hyde
// All Rights Reserved.
// You must accept the terms of that agreement to use this software.
*/
package mondrian.olap.fun;
import mondrian.olap.FunDef;
import mondrian.olap.Evaluator;
import mondrian.calc.Calc;
import mondrian.calc.ExpCompiler;
import mondrian.calc.ListCalc;
import mondrian.calc.impl.AbstractListCalc;
import mondrian.mdx.ResolvedFunCall;
import java.util.List;
import java.util.Set;
import java.util.HashSet;
import java.util.ArrayList;
/**
* Definition of the <code>Union</code> MDX function.
*
* @author jhyde
* @version $Id: //open/mondrian-release/3.2/src/main/mondrian/olap/fun/UnionFunDef.java#1 $
* @since Mar 23, 2006
*/
class UnionFunDef extends FunDefBase {
static final String[] ReservedWords = new String[] {"ALL", "DISTINCT"};
static final ReflectiveMultiResolver Resolver = new ReflectiveMultiResolver(
"Union",
"Union(<Set1>, <Set2>[, ALL])",
"Returns the union of two sets, optionally retaining duplicates.",
new String[] {"fxxx", "fxxxy"},
UnionFunDef.class,
ReservedWords);
public UnionFunDef(FunDef dummyFunDef) {
super(dummyFunDef);
}
public Calc compileCall(ResolvedFunCall call, ExpCompiler compiler) {
String allString = getLiteralArg(call, 2, "DISTINCT", ReservedWords);
final boolean all = allString.equalsIgnoreCase("ALL");
// todo: do at validate time
checkCompatible(call.getArg(0), call.getArg(1), null);
final ListCalc listCalc0 =
compiler.compileList(call.getArg(0));
final ListCalc listCalc1 =
compiler.compileList(call.getArg(1));
return new AbstractListCalc(call, new Calc[] {listCalc0, listCalc1}) {
public List evaluateList(Evaluator evaluator) {
List list0 = listCalc0.evaluateList(evaluator);
List list1 = listCalc1.evaluateList(evaluator);
return union(list0, list1, all);
}
};
}
<T> List<T> union(List<T> list0, List<T> list1, final boolean all) {
assert list0 != null;
assert list1 != null;
if (all) {
if (list0.isEmpty()) {
return list1;
}
if (list1.isEmpty()) {
return list0;
}
List<T> result = new ArrayList<T>();
result.addAll(list0);
result.addAll(list1);
return result;
} else {
Set<Object> added = new HashSet<Object>();
List<T> result = new ArrayList<T>();
FunUtil.addUnique(result, list0, added);
FunUtil.addUnique(result, list1, added);
return result;
}
}
}
// End UnionFunDef.java