content: /*******************************************************************************
   * Copyright (c) 2000, 2007 IBM Corporation and others.
   * All rights reserved. This program and the accompanying materials
   * are made available under the terms of the Eclipse Public License v1.0
   * which accompanies this distribution, and is available at
   * http://www.eclipse.org/legal/epl-v10.html
   *
   * Contributors:
   *   Robert M. Fuhrer (rfuhrer@watson.ibm.com), IBM Corporation - initial API and implementation
   *******************************************************************************/
  package org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets;
  
  import java.util.Iterator;
  
  import org.eclipse.core.runtime.Assert;
  import org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.types.ArrayType;
  import org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.types.TType;
  import org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints2.TTypes;
  
  public class SubTypesOfSingleton extends TypeSet {
  	/**
  	 * The "base type" defining the upper bound of this set.
  	 */
  	private final TType fUpperBound;
  
  	protected SubTypesOfSingleton(TType t, TypeSetEnvironment typeSetEnvironment) {
  		super(typeSetEnvironment);
  		Assert.isNotNull(t);
  		fUpperBound= t;
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#isUniverse()
  	 */
  	public boolean isUniverse() {
  		return fUpperBound.equals(getJavaLangObject());
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#makeClone()
  	 */
  	public TypeSet makeClone() {
  		return this; // new SubTypesOfSingleton(fUpperBound);
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#subTypes()
  	 */
  	public TypeSet subTypes() {
  		return this; // makeClone();
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#intersectedWith(org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet)
  	 */
  	public TypeSet specialCasesIntersectedWith(TypeSet other) {
  		if (other.isSingleton() && other.anyMember().equals(fUpperBound))
  			return other;		// xsect(subTypes(A),A) = A
  
  		if (other instanceof SubTypesOfSingleton) {
  			SubTypesOfSingleton otherSub= (SubTypesOfSingleton) other;
  
  			if (TTypes.canAssignTo(otherSub.fUpperBound, fUpperBound))
  				return otherSub; // .makeClone();
  			if (TTypes.canAssignTo(fUpperBound, otherSub.fUpperBound))
  				return this; // makeClone();
  		} else if (other.hasUniqueLowerBound()) {
  			TType otherLower= other.uniqueLowerBound();
  
  			if (otherLower.equals(fUpperBound))
  				return new SingletonTypeSet(fUpperBound, getTypeSetEnvironment());
  			if (otherLower != fUpperBound && TTypes.canAssignTo(fUpperBound, otherLower) ||
  					! TTypes.canAssignTo(otherLower, fUpperBound))
  				return getTypeSetEnvironment().getEmptyTypeSet();
  		}
  //		else if (other instanceof SubTypesSet) {
  //			SubTypesSet otherSub= (SubTypesSet) other;
  //			TypeSet otherUppers= otherSub.upperBound();
  //
  //			for(Iterator iter= otherUppers.iterator(); iter.hasNext(); ) {
  //				TType t= (TType) iter.next();
  //
  //				if ()
  //			}
  //		}
  		return null;
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#isEmpty()
  	 */
  	public boolean isEmpty() {
  		return false;
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#upperBound()
  	 */
  	public TypeSet upperBound() {
  		return new SingletonTypeSet(fUpperBound, getTypeSetEnvironment());
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#lowerBound()
  	 */
  	public TypeSet lowerBound() {
  		EnumeratedTypeSet e= enumerate();
  		return e.lowerBound();
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#hasUniqueLowerBound()
  	 */
  	public boolean hasUniqueLowerBound() {
  //		TypeSet lowerBound= lowerBound();
  
  //		return lowerBound.isSingleton();
  		return false; // fast, though perhaps inaccurate, but that's ok
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#hasUniqueUpperBound()
  	 */
  	public boolean hasUniqueUpperBound() {
  		return true;
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#uniqueLowerBound()
  	 */
  	public TType uniqueLowerBound() {
  		TypeSet lowerBound= lowerBound();
  
  		return lowerBound.anyMember();
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#uniqueUpperBound()
  	 */
  	public TType uniqueUpperBound() {
  		return fUpperBound;
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#contains(org.eclipse.wst.jsdt.core.TType)
  	 */
  	public boolean contains(TType t) {
  		if (t.equals(fUpperBound))
  			return true;
  		return TTypes.canAssignTo(t, fUpperBound);
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#containsAll(org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet)
  	 */
  	public boolean containsAll(TypeSet other) {
  		if (isUniverse())
  			return true;
  
  		// Optimization: if other is also a SubTypeOfSingleton, just compare bounds
  		if (other instanceof SubTypesOfSingleton) {
  			SubTypesOfSingleton otherSub= (SubTypesOfSingleton) other;
  			return TTypes.canAssignTo(otherSub.fUpperBound, fUpperBound);
  		}
  		// Optimization: if other is a SubTypesSet, just compare each of its bounds to mine
  		if (other instanceof SubTypesSet) {
  			SubTypesSet otherSub= (SubTypesSet) other;
  			TypeSet otherUpperBounds= otherSub.upperBound();
  
  			for(Iterator iter= otherUpperBounds.iterator(); iter.hasNext(); ) {
  				TType t= (TType) iter.next();
  				if (! TTypes.canAssignTo(t, fUpperBound))
  					return false;
  			}
  			return true;
  		}
  		// For now, no more tricks up my sleeve; get an iterator
  		for(Iterator iter= other.iterator(); iter.hasNext(); ) {
  			TType t= (TType) iter.next();
  
  			if (! TTypes.canAssignTo(t, fUpperBound))
  				return false;
  		}
  		return true;
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#iterator()
  	 */
  	public Iterator iterator() {
  		return enumerate().iterator();
  //		return new Iterator() {
  //			// First type returned is fUpperBound, then each of the subtypes, in turn
  //			//
  //			// If the upper bound is an array type, return the set of array types
  //			// { Array(subType(elementTypeOf(fUpperBound))) }
  //			private Set/*<TType>*/ subTypes= sTypeHierarchy.getAllSubtypes(getElementTypeOf(fUpperBound));
  //			private Iterator/*<TType>*/ subTypeIter= subTypes.iterator();
  //			private int nDims= getDimsOf(fUpperBound);
  //			private int idx=-1;
  //			public void remove() { /*do nothing*/}
  //			public boolean hasNext() { return idx < subTypes.size(); }
  //			public Object next() {
  //				int i=idx++;
  //				if (i < 0) return fUpperBound;
  //				return makePossiblyArrayTypeFor((TType) subTypeIter.next(), nDims);
  //			}
  //		};
  	}
  
  	/**
  	 * Returns the element type of the given TType, if an array type, or the
  	 * given TType itself, otherwise.
  	 */
  	private TType getElementTypeOf(TType t) {
  		if (t instanceof ArrayType)
  			return ((ArrayType) t).getElementType();
  		return t;
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#isSingleton()
  	 */
  	public boolean isSingleton() {
  		return getElementTypeOf(fUpperBound).getSubTypes().length == 0;
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#anyMember()
  	 */
  	public TType anyMember() {
  		return fUpperBound;
  	}
  
  	private EnumeratedTypeSet fEnumCache= null;
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet#enumerate()
  	 */
  	public EnumeratedTypeSet enumerate() {
  		if (fEnumCache == null) {
  			if (fUpperBound instanceof ArrayType) {
  				ArrayType at= (ArrayType) fUpperBound;
  				fEnumCache= EnumeratedTypeSet.makeArrayTypesForElements(TTypes.getAllSubTypesIterator(at.getComponentType()),getTypeSetEnvironment());
  			} else
  				fEnumCache= new EnumeratedTypeSet(TTypes.getAllSubTypesIterator(fUpperBound), getTypeSetEnvironment());
  
  			fEnumCache.add(fUpperBound);
  			fEnumCache.initComplete();
  		}
  		return fEnumCache;
  	}
  
  	public boolean equals(Object o) {
  		if (!(o instanceof SubTypesOfSingleton))
  			return false;
  		SubTypesOfSingleton other= (SubTypesOfSingleton) o;
  
  		return other.fUpperBound.equals(fUpperBound);
  	}
  
  	public String toString() {
  		return "<" + fID + ": subTypes(" + fUpperBound.getPrettySignature() + ")>"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
  	}
  }
  