001 /*
002 // $Id: //open/mondrian/src/main/mondrian/olap/fun/SetItemFunDef.java#7 $
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) 2006-2008 Julian Hyde
007 // All Rights Reserved.
008 // You must accept the terms of that agreement to use this software.
009 */
010 package mondrian.olap.fun;
011
012 import mondrian.olap.type.*;
013 import mondrian.olap.*;
014 import mondrian.calc.*;
015 import mondrian.calc.impl.AbstractTupleCalc;
016 import mondrian.calc.impl.AbstractMemberCalc;
017 import mondrian.mdx.ResolvedFunCall;
018
019 import java.util.List;
020 import java.util.ArrayList;
021
022 /**
023 * Definition of the <code><Set>.Item</code> MDX function.
024 *
025 * <p>Syntax:
026 * <blockquote><code>
027 * <Set>.Item(<Index>)<br/>
028 * <Set>.Item(<String Expression> [, ...])
029 * </code></blockquote>
030 *
031 * @author jhyde
032 * @version $Id: //open/mondrian/src/main/mondrian/olap/fun/SetItemFunDef.java#7 $
033 * @since Mar 23, 2006
034 */
035 class SetItemFunDef extends FunDefBase {
036 static final Resolver intResolver = new ReflectiveMultiResolver(
037 "Item",
038 "<Set>.Item(<Index>)",
039 "Returns a tuple from the set specified in <Set>. The tuple to be returned is specified by the zero-based position of the tuple in the set in <Index>.",
040 new String[] {"mmxn"},
041 SetItemFunDef.class);
042
043 static final Resolver stringResolver = new ResolverBase(
044 "Item",
045 "<Set>.Item(<String> [, ...])",
046 "Returns a tuple from the set specified in <Set>. The tuple to be returned is specified by the member name (or names) in <String>.",
047 Syntax.Method) {
048
049 public FunDef resolve(
050 Exp[] args, Validator validator, int[] conversionCount) {
051 if (args.length < 1) {
052 return null;
053 }
054 final Exp setExp = args[0];
055 if (!(setExp.getType() instanceof SetType)) {
056 return null;
057 }
058 final SetType setType = (SetType) setExp.getType();
059 int arity;
060 if (setType.getElementType() instanceof TupleType) {
061 arity = ((TupleType) setType.getElementType()).elementTypes.length;
062 } else {
063 arity = 1;
064 }
065 // All args must be strings.
066 for (int i = 1; i < args.length; i++) {
067 if (!validator.canConvert(
068 args[i], Category.String, conversionCount)) {
069 return null;
070 }
071 }
072 if (args.length - 1 != arity) {
073 throw Util.newError("Argument count does not match set's cardinality " + arity);
074 }
075 final int category = arity == 1 ? Category.Member : Category.Tuple;
076 FunDef dummy = createDummyFunDef(this, category, args);
077 return new SetItemFunDef(dummy);
078 }
079 };
080
081 public SetItemFunDef(FunDef dummyFunDef) {
082 super(dummyFunDef);
083 }
084
085 public Type getResultType(Validator validator, Exp[] args) {
086 SetType setType = (SetType) args[0].getType();
087 return setType.getElementType();
088 }
089
090 public Calc compileCall(ResolvedFunCall call, ExpCompiler compiler) {
091 final ListCalc listCalc =
092 compiler.compileList(call.getArg(0));
093 final Type elementType = ((SetType) listCalc.getType()).getElementType();
094 final boolean isString = call.getArgCount() < 2 ||
095 call.getArg(1).getType() instanceof StringType;
096 final IntegerCalc indexCalc;
097 final StringCalc[] stringCalcs;
098 List<Calc> calcList = new ArrayList<Calc>();
099 calcList.add(listCalc);
100 if (isString) {
101 indexCalc = null;
102 stringCalcs = new StringCalc[call.getArgCount() - 1];
103 for (int i = 0; i < stringCalcs.length; i++) {
104 stringCalcs[i] = compiler.compileString(call.getArg(i + 1));
105 calcList.add(stringCalcs[i]);
106 }
107 } else {
108 stringCalcs = null;
109 indexCalc = compiler.compileInteger(call.getArg(1));
110 calcList.add(indexCalc);
111 }
112 Calc[] calcs = calcList.toArray(new Calc[calcList.size()]);
113 if (elementType instanceof TupleType) {
114 final TupleType tupleType = (TupleType) elementType;
115 final Member[] nullTuple = makeNullTuple(tupleType);
116 if (isString) {
117 return new AbstractTupleCalc(call, calcs) {
118 public Member[] evaluateTuple(Evaluator evaluator) {
119 final List<Member[]> list = listCalc.evaluateList(evaluator);
120 assert list != null;
121 String[] results = new String[stringCalcs.length];
122 for (int i = 0; i < stringCalcs.length; i++) {
123 results[i] =
124 stringCalcs[i].evaluateString(evaluator);
125 }
126 listLoop:
127 for (Member[] members : list) {
128 for (int j = 0; j < results.length; j++) {
129 String result = results[j];
130 final Member member = members[j];
131 if (!matchMember(member, result)) {
132 continue listLoop;
133 }
134 }
135 // All members match. Return the current one.
136 return members;
137 }
138 // We use 'null' to represent the null tuple. Don't
139 // know why.
140 return null;
141 }
142 };
143 } else {
144 return new AbstractTupleCalc(call, calcs) {
145 public Member[] evaluateTuple(Evaluator evaluator) {
146 final List<Member[]> list = listCalc.evaluateList(evaluator);
147 assert list != null;
148 final int index = indexCalc.evaluateInteger(evaluator);
149 int listSize = list.size();
150 if (index >= listSize || index < 0) {
151 return nullTuple;
152 } else {
153 return (Member[]) list.get(index);
154 }
155 }
156 };
157 }
158 } else {
159 final MemberType memberType = (MemberType) elementType;
160 final Member nullMember = makeNullMember(memberType);
161 if (isString) {
162 return new AbstractMemberCalc(call, calcs) {
163 public Member evaluateMember(Evaluator evaluator) {
164 final List<Member> list = listCalc.evaluateList(evaluator);
165 assert list != null;
166 final String result =
167 stringCalcs[0].evaluateString(evaluator);
168 for (Member member : list) {
169 if (matchMember(member, result)) {
170 return member;
171 }
172 }
173 return nullMember;
174 }
175 };
176 } else {
177 return new AbstractMemberCalc(call, calcs) {
178 public Member evaluateMember(Evaluator evaluator) {
179 final List list = listCalc.evaluateList(evaluator);
180 assert list != null;
181 final int index = indexCalc.evaluateInteger(evaluator);
182 int listSize = list.size();
183 if (index >= listSize || index < 0) {
184 return nullMember;
185 } else {
186 return (Member) list.get(index);
187 }
188 }
189 };
190 }
191 }
192 }
193
194 private static boolean matchMember(final Member member, String name) {
195 return member.getName().equals(name);
196 }
197
198 Object makeNullMember(Evaluator evaluator, Exp[] args) {
199 final Type elementType = ((SetType) args[0].getType()).getElementType();
200 return makeNullMemberOrTuple(elementType);
201 }
202
203 Object makeNullMemberOrTuple(final Type elementType) {
204 if (elementType instanceof MemberType) {
205 MemberType memberType = (MemberType) elementType;
206 return makeNullMember(memberType);
207 } else if (elementType instanceof TupleType) {
208 return makeNullTuple((TupleType) elementType);
209 } else {
210 throw Util.newInternal("bad type " + elementType);
211 }
212 }
213 }
214
215 // End SetItemFunDef.java