| 1 | package com.hammurapi.extract; |
| 2 | |
| 3 | import java.util.Map; |
| 4 | import java.util.Set; |
| 5 | |
| 6 | import com.hammurapi.extract.ComparisonResult.Type; |
| 7 | |
| 8 | |
| 9 | /** |
| 10 | * This predicate evaluates to true if argument is of a particular type. |
| 11 | * @author Pavel Vlasov. |
| 12 | * |
| 13 | * @param <T> |
| 14 | */ |
| 15 | public class InstanceOfPredicate<T, C> implements Predicate<T, C>, Mappable<T,Boolean,C> { |
| 16 | |
| 17 | private Class<?> instanceType; |
| 18 | private Extractor<T, Object, C> extractor; |
| 19 | |
| 20 | @SuppressWarnings("unchecked") |
| 21 | public InstanceOfPredicate(Extractor<T, Object, C> extractor, Class<?> instanceType) { |
| 22 | this.extractor = extractor; |
| 23 | if (instanceType.isPrimitive()) { |
| 24 | if (boolean.class.equals(instanceType)) { |
| 25 | this.instanceType = (Class<? extends T>) Boolean.class; |
| 26 | } else if (char.class.equals(instanceType)) { |
| 27 | this.instanceType = (Class<? extends T>) Character.class; |
| 28 | } else if (byte.class.equals(instanceType)) { |
| 29 | this.instanceType = (Class<? extends T>) Byte.class; |
| 30 | } else if (short.class.equals(instanceType)) { |
| 31 | this.instanceType = (Class<? extends T>) Short.class; |
| 32 | } else if (int.class.equals(instanceType)) { |
| 33 | this.instanceType = (Class<? extends T>) Integer.class; |
| 34 | } else if (long.class.equals(instanceType)) { |
| 35 | this.instanceType = (Class<? extends T>) Long.class; |
| 36 | } else if (float.class.equals(instanceType)) { |
| 37 | this.instanceType = (Class<? extends T>) Float.class; |
| 38 | } else if (double.class.equals(instanceType)) { |
| 39 | this.instanceType = (Class<? extends T>) Double.class; |
| 40 | } else if (void.class.equals(instanceType)) { |
| 41 | this.instanceType = null; |
| 42 | } |
| 43 | } else { |
| 44 | this.instanceType = instanceType; |
| 45 | } |
| 46 | } |
| 47 | |
| 48 | @SuppressWarnings("unchecked") |
| 49 | public ComparisonResult compareTo(Extractor<T, Boolean, C> otherPredicate) { |
| 50 | if (instanceType==null) { |
| 51 | return False.getInstance().compareTo((Extractor<Object, Boolean, Object>) otherPredicate); |
| 52 | } |
| 53 | |
| 54 | if (otherPredicate instanceof InstanceOfPredicate) { |
| 55 | ComparisonResult ecr = extractor.compareTo(((InstanceOfPredicate<T, C>) otherPredicate).extractor); |
| 56 | if (ecr == null || ecr.getType()!=ComparisonResult.Type.EQUAL) { |
| 57 | return ComparisonResult.NOT_EQUAL_NM; |
| 58 | } |
| 59 | |
| 60 | Class<?> otherInstanceType = ((InstanceOfPredicate<T, C>) otherPredicate).instanceType; |
| 61 | if (otherInstanceType.equals(instanceType)) { |
| 62 | return new ComparisonResult(Type.EQUAL, ecr.getIndexMap()); |
| 63 | } |
| 64 | if (instanceType.isAssignableFrom(otherInstanceType)) { |
| 65 | return new ComparisonResult(Type.LESS_RESTRICTIVE, ecr.getIndexMap()); |
| 66 | } |
| 67 | if (otherInstanceType.isAssignableFrom(instanceType)) { |
| 68 | return new ComparisonResult(Type.MORE_RESTRICTIVE, ecr.getIndexMap()); |
| 69 | } |
| 70 | |
| 71 | // No multiple inheritance in Java - if both types are classes, then they |
| 72 | // are mutually exclusive - i.e. a instanceof String is opposite less restrictive than |
| 73 | // a instanceof Integer. |
| 74 | if (!instanceType.isInterface() && !otherInstanceType.isInterface()) { |
| 75 | return new ComparisonResult(Type.OPPOSITE_LESS_RESTRICTIVE, ecr.getIndexMap()); |
| 76 | } |
| 77 | |
| 78 | } |
| 79 | |
| 80 | // True is less restrictive than anything but self. |
| 81 | if (otherPredicate instanceof True) { |
| 82 | return ComparisonResult.MORE_RESTRICTIVE_NM; |
| 83 | } |
| 84 | |
| 85 | // False is more restrictive than anything but self. |
| 86 | if (otherPredicate instanceof False) { |
| 87 | return ComparisonResult.LESS_RESTRICTIVE_NM; |
| 88 | } |
| 89 | |
| 90 | if (otherPredicate instanceof FacadeExtractor) { |
| 91 | ComparisonResult cr = otherPredicate.compareTo(this); |
| 92 | if (cr==null) { |
| 93 | return cr; |
| 94 | } |
| 95 | switch (cr.getType()) { |
| 96 | case EQUAL: |
| 97 | case NOT_EQUAL: |
| 98 | case OPPOSITE: |
| 99 | return cr; |
| 100 | case LESS_RESTRICTIVE: |
| 101 | return new ComparisonResult(Type.MORE_RESTRICTIVE, ComparisonResult.inverse(cr.getIndexMap(), parameterIndices())); |
| 102 | case MORE_RESTRICTIVE: |
| 103 | return new ComparisonResult(Type.LESS_RESTRICTIVE, ComparisonResult.inverse(cr.getIndexMap(), parameterIndices())); |
| 104 | case OPPOSITE_LESS_RESTRICTIVE: |
| 105 | return new ComparisonResult(Type.OPPOSITE_LESS_RESTRICTIVE, ComparisonResult.inverse(cr.getIndexMap(), parameterIndices())); |
| 106 | case OPPOSITE_MORE_RESTRICTIVE: |
| 107 | return new ComparisonResult(Type.OPPOSITE_MORE_RESTRICTIVE, ComparisonResult.inverse(cr.getIndexMap(), parameterIndices())); |
| 108 | } |
| 109 | } |
| 110 | |
| 111 | return ComparisonResult.NOT_EQUAL_NM; |
| 112 | } |
| 113 | |
| 114 | @SuppressWarnings({ "unchecked", "rawtypes" }) |
| 115 | public Boolean extract(C context, Map<C, Map<Extractor<T, ? super Boolean, C>, ? super Boolean>> cache, T... obj) { |
| 116 | return instanceType==null ? false : instanceType.isInstance(extractor.extract(context, (Map) cache, obj)); |
| 117 | } |
| 118 | |
| 119 | public Set<Integer> parameterIndices() { |
| 120 | return extractor.parameterIndices(); |
| 121 | } |
| 122 | |
| 123 | public boolean isContextDependent() { |
| 124 | return false; |
| 125 | } |
| 126 | |
| 127 | @Override |
| 128 | public String toString() { |
| 129 | return "InstanceOfPredicate [instanceType=" + instanceType + ", extractor=" + extractor + "]"; |
| 130 | } |
| 131 | |
| 132 | @Override |
| 133 | public double getCost() { |
| 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | @Override |
| 138 | public Extractor<T, Boolean, C> map(int[] map) { |
| 139 | if (extractor instanceof Mappable) { |
| 140 | Extractor<T,Object,C> mapped = ((Mappable<T,Object,C>) extractor).map(map); |
| 141 | if (mapped!=null) { |
| 142 | return new InstanceOfPredicate<T, C>(mapped, instanceType); |
| 143 | } |
| 144 | } |
| 145 | return null; |
| 146 | } |
| 147 | |
| 148 | /** |
| 149 | * @return Extractor which return value is checked for instanceof. |
| 150 | */ |
| 151 | public Extractor<T, Object, C> getExtractor() { |
| 152 | return extractor; |
| 153 | } |
| 154 | |
| 155 | public Class<?> getInstanceType() { |
| 156 | return instanceType; |
| 157 | } |
| 158 | } |