case-study/jdt-before/core refactoring/org/eclipse/jdt/internal/corext/refactoring/typeconstraints/typesets/TypeSetIntersection.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2011 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Eclipse Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/epl-v10.html
   7  *
   8  * Contributors:
   9  *   Robert M. Fuhrer (rfuhrer@watson.ibm.com), IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets;
  12
  13 import java.util.Iterator;
  14
  15 import org.eclipse.jdt.internal.corext.refactoring.typeconstraints.types.TType;
  16 import org.eclipse.jdt.internal.corext.refactoring.typeconstraints2.TTypes;
  17
  18 public class TypeSetIntersection extends TypeSet {
  19         private TypeSet fLHS;
  20         private TypeSet fRHS;
  21
  22         public TypeSetIntersection(TypeSet lhs, TypeSet rhs) {
  23                 super(lhs.getTypeSetEnvironment());
  24                 fLHS= lhs;
  25                 fRHS= rhs;
  26         }
  27
  28         /**
  29          * @return Returns the LHS.
  30          */
  31         public TypeSet getLHS() {
  32                 return fLHS;
  33         }
  34
  35         /**
  36          * @return Returns the RHS.
  37          */
  38         public TypeSet getRHS() {
  39                 return fRHS;
  40         }
  41
  42         /* (non-Javadoc)
  43          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#isUniverse()
  44          */
  45         @Override
  46         public boolean isUniverse() {
  47                 return fLHS.isUniverse() && fRHS.isUniverse();
  48         }
  49
  50         /* (non-Javadoc)
  51          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#makeClone()
  52          */
  53         @Override
  54         public TypeSet makeClone() {
  55                 return this; //new TypeSetIntersection(fLHS.makeClone(), fRHS.makeClone());
  56         }
  57
  58         /* (non-Javadoc)
  59          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#isEmpty()
  60          */
  61         @Override
  62         public boolean isEmpty() {
  63                 if (fLHS.isEmpty() || fRHS.isEmpty())
  64                         return true;
  65                 if (fLHS.isUniverse() || fRHS.isUniverse())
  66                         return false;
  67                 // Another quick check we can make before jumping to the expensive stuff
  68                 if (fLHS.contains(getJavaLangObject()) && fRHS.contains(getJavaLangObject()))
  69                         return false;
  70
  71 //              TypeSet lhsLB= fLHS.lowerBound();
  72 //              TypeSet rhsUB= fRHS.upperBound();
  73 //
  74 //              // Avoid the infinite recursion that will occur if lhsLB == fLHS && rhsUB == fRHS
  75 //              if ((!lhsLB.equals(fLHS) || !rhsUB.equals(fRHS)) &&
  76 //                              !lhsLB.intersectedWith(rhsUB).isEmpty())
  77 //                      return false;
  78 //
  79 //              if (areAllSuperTypesOf(lhsLB, rhsUB))
  80 //                      return true;
  81 //
  82 //              TypeSet lhsUB= fLHS.upperBound();
  83 //              TypeSet rhsLB= fRHS.lowerBound();
  84 //
  85 //              if (!lhsUB.intersectedWith(rhsLB).isEmpty())
  86 //                      return false;
  87 //
  88 //              if (areAllSuperTypesOf(rhsLB, lhsUB))
  89 //                      return true;
  90
  91                 return false;
  92         }
  93
  94         /* (non-Javadoc)
  95          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#contains(TType)
  96          */
  97         @Override
  98         public boolean contains(TType t) {
  99                 return fLHS.contains(t) && fRHS.contains(t);
 100         }
 101
 102         /* (non-Javadoc)
 103          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#containsAll(org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet)
 104          */
 105         @Override
 106         public boolean containsAll(TypeSet s) {
 107                 return fLHS.containsAll(s) && fRHS.containsAll(s);
 108         }
 109
 110         /* (non-Javadoc)
 111          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#subTypes()
 112          */
 113         @Override
 114         public TypeSet subTypes() {
 115                 if (isUniverse() || contains(getJavaLangObject()))
 116                         return getTypeSetEnvironment().getUniverseTypeSet();
 117                 // sub(xsect(sub(a),sub(b))) == xsect(sub(a),sub(b))
 118                 if ((fLHS instanceof SubTypesSet || fLHS instanceof SubTypesOfSingleton) &&
 119                         (fRHS instanceof SubTypesSet || fRHS instanceof SubTypesOfSingleton))
 120                         return this;
 121                 return getTypeSetEnvironment().createSubTypesSet(this);
 122         }
 123
 124         /* (non-Javadoc)
 125          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#superTypes()
 126          */
 127         @Override
 128         public TypeSet superTypes() {
 129                 // super(xsect(super(a),super(b))) == xsect(super(a),super(b))
 130                 if ((fLHS instanceof SuperTypesSet || fLHS instanceof SuperTypesOfSingleton) &&
 131                         (fRHS instanceof SuperTypesSet || fRHS instanceof SuperTypesOfSingleton))
 132                         return this;
 133                 return getTypeSetEnvironment().createSuperTypesSet(this);
 134         }
 135
 136         /* (non-Javadoc)
 137          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#upperBound()
 138          */
 139         @Override
 140         public TypeSet upperBound() {
 141                 if (fLHS.contains(getJavaLangObject()) && fRHS.contains(getJavaLangObject()))
 142                         return new SingletonTypeSet(getTypeSetEnvironment().getJavaLangObject(), getTypeSetEnvironment());
 143
 144                 if (fEnumCache != null) return fEnumCache.upperBound();
 145
 146                 EnumeratedTypeSet lhsSet= fLHS.enumerate();
 147                 EnumeratedTypeSet rhsSet= fRHS.enumerate();
 148                 TypeSet xsect= lhsSet.intersectedWith(rhsSet);
 149
 150                 return xsect.upperBound();
 151         }
 152
 153         /* (non-Javadoc)
 154          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#lowerBound()
 155          */
 156         @Override
 157         public TypeSet lowerBound() {
 158                 if (fLHS.hasUniqueLowerBound() && fRHS.hasUniqueLowerBound()) {
 159                         TType lhsBound= fLHS.uniqueLowerBound();
 160                         TType rhsBound= fRHS.uniqueLowerBound();
 161
 162                         if (lhsBound.equals(rhsBound))
 163                                 return new SingletonTypeSet(lhsBound, getTypeSetEnvironment());
 164                         else if (TTypes.canAssignTo(lhsBound, rhsBound))
 165                                 return new SingletonTypeSet(rhsBound, getTypeSetEnvironment());
 166                         else if (TTypes.canAssignTo(rhsBound, lhsBound))
 167                                 return new SingletonTypeSet(lhsBound, getTypeSetEnvironment());
 168                 }
 169                 if (fEnumCache != null) return fEnumCache.lowerBound();
 170
 171                 EnumeratedTypeSet lhsSet= fLHS.enumerate();
 172                 EnumeratedTypeSet rhsSet= fRHS.enumerate();
 173                 TypeSet xsect= lhsSet.intersectedWith(rhsSet);
 174
 175                 return xsect.lowerBound();
 176         }
 177
 178         @Override
 179         protected TypeSet specialCasesIntersectedWith(TypeSet s2) {
 180                 if (s2.equals(fLHS)) // xsect(s2,xsect(s2,?)) = xsect(s2,?)
 181                         return this;
 182                 if (s2.equals(fRHS)) // xsect(s2,xsect(?,s2)) = xsect(?,s2)
 183                         return this;
 184                 if (s2 instanceof TypeSetIntersection) {
 185                         TypeSetIntersection x2= (TypeSetIntersection) s2;
 186                         //
 187                         // The following should use a "quick equals()" guaranteed to be constant-time
 188                         //
 189                         // xsect(xsect(A,B),xsect(A,C)) = xsect(xsect(A,B),C)
 190                         if (fLHS.equals(x2.fLHS))
 191                                 return new TypeSetIntersection(this, x2.fRHS);
 192                         // xsect(xsect(A,B),xsect(C,A)) = xsect(xsect(A,B),C)
 193                         if (fLHS.equals(x2.fRHS))
 194                                 return new TypeSetIntersection(this, x2.fLHS);
 195                         // xsect(xsect(A,B),xsect(B,C)) = xsect(xsect(A,B),C)
 196                         if (fRHS.equals(x2.fLHS))
 197                                 return new TypeSetIntersection(this, x2.fRHS);
 198                         // xsect(xsect(A,B),xsect(C,B)) = xsect(xsect(A,B),C)
 199                         if (fRHS.equals(x2.fRHS))
 200                                 return new TypeSetIntersection(this, x2.fLHS);
 201                 }
 202                 return null;
 203         }
 204
 205         /* (non-Javadoc)
 206          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#isSingleton()
 207          */
 208         @Override
 209         public boolean isSingleton() {
 210                 if (fEnumCache != null) return fEnumCache.isSingleton();
 211
 212                 int count= 0;
 213                 for(Iterator<TType> lhsIter= fLHS.iterator(); lhsIter.hasNext(); ) {
 214                         TType t= lhsIter.next();
 215                         if (fRHS.contains(t))
 216                                 count++;
 217                         if (count > 1)
 218                                 return false;
 219                 }
 220                 return (count == 1);
 221         }
 222
 223         /* (non-Javadoc)
 224          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#anyMember()
 225          */
 226         @Override
 227         public TType anyMember() {
 228                 if (fEnumCache != null) return fEnumCache.anyMember();
 229
 230                 for(Iterator<TType> lhsIter= fLHS.iterator(); lhsIter.hasNext(); ) {
 231                         TType t= lhsIter.next();
 232                         if (fRHS.contains(t))
 233                                 return t;
 234                 }
 235                 return null;
 236         }
 237
 238         /* (non-Javadoc)
 239          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#iterator()
 240          */
 241         @Override
 242         public Iterator<TType> iterator() {
 243                 return enumerate().iterator();
 244
 245 //              return new Iterator() {
 246 //                      private Iterator fLHSIter= fLHS.iterator();
 247 //                      private TType fNext= null;
 248 //                      public void remove() {
 249 //                              throw new IllegalStateException("Unimplemented");
 250 //                      }
 251 //                      private void advance() {
 252 //                              for(; fLHSIter.hasNext(); ) {
 253 //                                      TType t= (TType) fLHSIter.next();
 254 //                                      if (fRHS.contains(t)) {
 255 //                                              fNext= t;
 256 //                                              break;
 257 //                                      }
 258 //                              }
 259 //                      }
 260 //                      public boolean hasNext() {
 261 //                              if (fNext == null)
 262 //                                      advance();
 263 //                              return fNext != null;
 264 //                      }
 265 //                      public Object next() {
 266 //                              if (fNext == null)
 267 //                                      advance();
 268 //                              if (fNext == null)
 269 //                                      throw new NoSuchElementException("No more elements in TypeSetIntersection");
 270 //                              TType result= fNext;
 271 //                              fNext= null;
 272 //                              return result;
 273 //                      }
 274 //              };
 275         }
 276
 277         /* (non-Javadoc)
 278          * @see java.lang.Object#equals(java.lang.Object)
 279          */
 280         @Override
 281         public boolean equals(Object o) {
 282                 if (o instanceof TypeSetIntersection) {
 283                         TypeSetIntersection other= (TypeSetIntersection) o;
 284                         return other.fLHS.equals(fLHS) && other.fRHS.equals(fRHS);
 285                 } else
 286                         return false;
 287         }
 288
 289         @Override
 290         public int hashCode() {
 291                 return fLHS.hashCode() * 37 + fRHS.hashCode();
 292         }
 293
 294         @Override
 295         public String toString() {
 296                 return "<" + fID + ": intersect(" + fLHS + "," + fRHS + ")>"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
 297         }
 298
 299         /* (non-Javadoc)
 300          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#hasUniqueLowerBound()
 301          */
 302         @Override
 303         public boolean hasUniqueLowerBound() {
 304                 return false;
 305         }
 306
 307         /* (non-Javadoc)
 308          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#hasUniqueUpperBound()
 309          */
 310         @Override
 311         public boolean hasUniqueUpperBound() {
 312                 return false;
 313         }
 314
 315         /* (non-Javadoc)
 316          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#uniqueLowerBound()
 317          */
 318         @Override
 319         public TType uniqueLowerBound() {
 320                 return null;
 321         }
 322
 323         /* (non-Javadoc)
 324          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#uniqueUpperBound()
 325          */
 326         @Override
 327         public TType uniqueUpperBound() {
 328                 return null;
 329         }
 330
 331         private EnumeratedTypeSet fEnumCache= null;
 332
 333         /* (non-Javadoc)
 334          * @see org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#enumerate()
 335          */
 336         @Override
 337         public EnumeratedTypeSet enumerate() {
 338                 if (fEnumCache == null) {
 339                         EnumeratedTypeSet lhsSet= fLHS.enumerate();
 340                         EnumeratedTypeSet rhsSet= fRHS.enumerate();
 341                         fEnumCache= lhsSet.intersectedWith(rhsSet).enumerate();
 342                 }
 343
 344                 return fEnumCache;
 345         }
 346 }