/*
// $Id: //open/mondrian-release/3.2/src/main/mondrian/olap/fun/AsFunDef.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) 2009-2009 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.impl.AbstractMemberIterCalc;
import mondrian.calc.impl.AbstractTupleIterCalc;
import mondrian.mdx.ResolvedFunCall;
import mondrian.mdx.NamedSetExpr;
import mondrian.olap.*;
import mondrian.olap.type.SetType;
import java.util.List;
/**
* Definition of the <code>AS</code> MDX operator.
*
* <p>Using <code>AS</code>, you can define an alias for an MDX expression
* anywhere it appears in a query, and use that alias as you would a calculated
* yet.
*
* @author jhyde
* @version $Id: //open/mondrian-release/3.2/src/main/mondrian/olap/fun/AsFunDef.java#1 $
* @since Oct 7, 2009
*/
class AsFunDef extends FunDefBase {
public static final Resolver RESOLVER = new ResolverImpl();
private final Query.ScopedNamedSet scopedNamedSet;
/**
* Creates an AsFunDef.
*
* @param scopedNamedSet Named set definition
*/
private AsFunDef(Query.ScopedNamedSet scopedNamedSet) {
super(
"AS",
"<Expression> AS <Name>",
"Assigns an alias to an expression",
"ixxn");
this.scopedNamedSet = scopedNamedSet;
}
public Calc compileCall(ResolvedFunCall call, ExpCompiler compiler) {
// Argument 0, the definition of the set, has been resolved since the
// scoped named set was created. Implicit conversions, like converting
// a member to a set, have been performed. Use the new expression.
scopedNamedSet.setExp(call.getArg(0));
if (((SetType) call.getType()).getArity() == 1) {
return new AbstractMemberIterCalc(call, new Calc[0]) {
public Iterable<Member> evaluateMemberIterable(
Evaluator evaluator)
{
final Evaluator.NamedSetEvaluator namedSetEvaluator =
evaluator.getNamedSetEvaluator(scopedNamedSet, false);
return namedSetEvaluator.evaluateMemberIterable();
}
};
} else {
return new AbstractTupleIterCalc(call, new Calc[0]) {
public Iterable<Member []> evaluateTupleIterable(
Evaluator evaluator)
{
final Evaluator.NamedSetEvaluator namedSetEvaluator =
evaluator.getNamedSetEvaluator(scopedNamedSet, false);
return namedSetEvaluator.evaluateTupleIterable();
}
};
}
}
private static class ResolverImpl extends ResolverBase {
public ResolverImpl() {
super("AS", null, null, Syntax.Infix);
}
public FunDef resolve(
Exp[] args,
Validator validator,
List<Conversion> conversions)
{
final Exp exp = args[0];
if (!validator.canConvert(
0, args[0], Category.Set, conversions))
{
return null;
}
// By the time resolve is called, the id argument has already been
// resolved... to a named set, namely itself. That's not pretty.
// We'd rather it stayed as an id, and we'd rather that a named set
// was not visible in the scope that defines it. But we can work
// with this.
final String name =
((NamedSetExpr) args[1]).getNamedSet().getName();
final Query.ScopedNamedSet scopedNamedSet =
(Query.ScopedNamedSet) ((NamedSetExpr) args[1]).getNamedSet();
// validator.getQuery().createScopedNamedSet(
// name, (QueryPart) exp, exp);
return new AsFunDef(scopedNamedSet);
}
}
}
// End AsFunDef.java