001 /*
002 // $Id: //open/mondrian/src/main/mondrian/calc/impl/BetterExpCompiler.java#9 $
003 // This software is subject to the terms of the Common Public License
004 // Agreement, available at the following URL:
005 // http://www.opensource.org/licenses/cpl.html.
006 // Copyright (C) 2006-2007 Julian Hyde
007 // All Rights Reserved.
008 // You must accept the terms of that agreement to use this software.
009 */
010 package mondrian.calc.impl;
011
012 import mondrian.olap.*;
013 import mondrian.olap.type.*;
014 import mondrian.calc.*;
015
016 import java.util.List;
017 import java.util.ArrayList;
018
019 /**
020 * Enhanced expression compiler. It can generate code to convert between
021 * scalar types.
022 *
023 * @author jhyde
024 * @version $Id: //open/mondrian/src/main/mondrian/calc/impl/BetterExpCompiler.java#9 $
025 * @since Sep 29, 2005
026 */
027 public class BetterExpCompiler extends AbstractExpCompiler {
028 public BetterExpCompiler(Evaluator evaluator, Validator validator) {
029 super(evaluator, validator);
030 }
031
032 public BetterExpCompiler(
033 Evaluator evaluator,
034 Validator validator,
035 List<ResultStyle> resultStyles)
036 {
037 super(evaluator, validator, resultStyles);
038 }
039
040 public DoubleCalc compileDouble(Exp exp) {
041 final Calc calc = compileScalar(exp, false);
042 if (calc instanceof DoubleCalc) {
043 return (DoubleCalc) calc;
044 } else if (calc instanceof IntegerCalc) {
045 final IntegerCalc integerCalc = (IntegerCalc) calc;
046 return new AbstractDoubleCalc(exp, new Calc[] {integerCalc}) {
047 public double evaluateDouble(Evaluator evaluator) {
048 final int result = integerCalc.evaluateInteger(evaluator);
049 return (double) result;
050 }
051 };
052 } else {
053 throw Util.newInternal("cannot cast " + exp);
054 }
055 }
056
057 public TupleCalc compileTuple(Exp exp) {
058 final Calc calc = compile(exp);
059 final Type type = exp.getType();
060 if (type instanceof TupleType) {
061 assert calc instanceof TupleCalc;
062 return (TupleCalc) calc;
063 } else if (type instanceof MemberType) {
064 assert calc instanceof MemberCalc;
065 final MemberCalc memberCalc = (MemberCalc) calc;
066 return new AbstractTupleCalc(exp, new Calc[] {memberCalc}) {
067 public Member[] evaluateTuple(Evaluator evaluator) {
068 return new Member[] {memberCalc.evaluateMember(evaluator)};
069 }
070 };
071 } else {
072 throw Util.newInternal("cannot cast " + exp);
073 }
074 }
075
076 public ListCalc compileList(Exp exp, boolean mutable) {
077 final ListCalc listCalc = super.compileList(exp, mutable);
078 if (mutable && listCalc.getResultStyle() == ResultStyle.LIST) {
079 // Wrap the expression in an expression which creates a mutable
080 // copy.
081 return new CopyListCalc(listCalc);
082 }
083 return listCalc;
084 }
085
086 private static class CopyListCalc extends AbstractListCalc {
087 private final ListCalc listCalc;
088
089 public CopyListCalc(ListCalc listCalc) {
090 super(new DummyExp(listCalc.getType()), new Calc[]{listCalc});
091 this.listCalc = listCalc;
092 }
093
094 public List evaluateList(Evaluator evaluator) {
095 List list = listCalc.evaluateList(evaluator);
096 return new ArrayList(list);
097 }
098 }
099 }
100
101 // End BetterExpCompiler.java