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10 package mondrian.olap.fun;
11
12 import mondrian.olap.*;
13 import mondrian.calc.Calc;
14 import mondrian.calc.ExpCompiler;
15 import mondrian.calc.impl.ConstantCalc;
16 import mondrian.calc.impl.AbstractCalc;
17 import mondrian.mdx.ResolvedFunCall;
18
19 import java.util.List  ;
20 import java.util.ArrayList ;
21
22
37 class CaseMatchFunDef extends FunDefBase {
38 static final ResolverImpl Resolver = new ResolverImpl();
39
40 private CaseMatchFunDef(FunDef dummyFunDef) {
41 super(dummyFunDef);
42 }
43
44 public Calc compileCall(ResolvedFunCall call, ExpCompiler compiler) {
45 final Exp[] args = call.getArgs();
46 final List <Calc> calcList = new ArrayList <Calc>();
47 final Calc valueCalc =
48 compiler.compileScalar(args[0], true);
49 calcList.add(valueCalc);
50 final int matchCount = (args.length - 1) / 2;
51 final Calc[] matchCalcs = new Calc[matchCount];
52 final Calc[] exprCalcs = new Calc[matchCount];
53 for (int i = 0, j = 1; i < exprCalcs.length; i++) {
54 matchCalcs[i] =
55 compiler.compileScalar(args[j++], true);
56 calcList.add(matchCalcs[i]);
57 exprCalcs[i] =
58 compiler.compileScalar(args[j++], true);
59 calcList.add(exprCalcs[i]);
60 }
61 final Calc defaultCalc =
62 args.length % 2 == 0 ?
63 compiler.compileScalar(args[args.length - 1], true) :
64 ConstantCalc.constantNull(call.getType());
65 calcList.add(defaultCalc);
66 final Calc[] calcs = calcList.toArray(new Calc[calcList.size()]);
67
68 return new AbstractCalc(call) {
69 public Object evaluate(Evaluator evaluator) {
70
71 Object value = valueCalc.evaluate(evaluator);
72 for (int i = 0; i < matchCalcs.length; i++) {
73 Object match = matchCalcs[i].evaluate(evaluator);
74 if (match.equals(value)) {
75 return exprCalcs[i].evaluate(evaluator);
76 }
77 }
78 return defaultCalc.evaluate(evaluator);
79 }
80
81 public Calc[] getCalcs() {
82 return calcs;
83 }
84 };
85 }
86
87 private static class ResolverImpl extends ResolverBase {
88 private ResolverImpl() {
89 super(
90 "_CaseMatch",
91 "Case <Expression> When <Expression> Then <Expression> [...] [Else <Expression>] End",
92 "Evaluates various expressions, and returns the corresponding expression for the first which matches a particular value.",
93 Syntax.Case);
94 }
95
96 public FunDef resolve(
97 Exp[] args, Validator validator, int[] conversionCount) {
98 if (args.length < 3) {
99 return null;
100 }
101 int valueType = args[0].getCategory();
102 int returnType = args[2].getCategory();
103 int j = 0;
104 int clauseCount = (args.length - 1) / 2;
105 int mismatchingArgs = 0;
106 if (!validator.canConvert(args[j++], valueType, conversionCount)) {
107 mismatchingArgs++;
108 }
109 for (int i = 0; i < clauseCount; i++) {
110 if (!validator.canConvert(args[j++], valueType, conversionCount)) {
111 mismatchingArgs++;
112 }
113 if (!validator.canConvert(args[j++], returnType, conversionCount)) {
114 mismatchingArgs++;
115 }
116 }
117 if (j < args.length) {
118 if (!validator.canConvert(args[j++], returnType, conversionCount)) {
119 mismatchingArgs++;
120 }
121 }
122 Util.assertTrue(j == args.length);
123 if (mismatchingArgs != 0) {
124 return null;
125 }
126
127 FunDef dummy = createDummyFunDef(this, returnType, args);
128 return new CaseMatchFunDef(dummy);
129 }
130
131 public boolean requiresExpression(int k) {
132 return true;
133 }
134 }
135 }
136
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