001    /*
002     * Copyright 2010-2013 JetBrains s.r.o.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package org.jetbrains.jet.lang.resolve.calls.inference;
018    
019    import com.google.common.collect.Sets;
020    import org.jetbrains.annotations.NotNull;
021    import org.jetbrains.jet.lang.descriptors.TypeParameterDescriptor;
022    import org.jetbrains.jet.lang.types.JetType;
023    import org.jetbrains.jet.lang.types.Variance;
024    
025    import java.util.Set;
026    
027    public class TypeValue implements BoundsOwner {
028        private final Set<TypeValue> upperBounds = Sets.newLinkedHashSet();
029        private final Set<TypeValue> lowerBounds = Sets.newLinkedHashSet();
030    
031        private final Variance positionVariance;
032        private final TypeParameterDescriptor typeParameterDescriptor; // Null for known types
033        private final JetType originalType;
034        private JetType value; // For an unknown - the value found by constraint resolution, for a known - just it's value
035    
036        // Unknown type
037        public TypeValue(@NotNull TypeParameterDescriptor typeParameterDescriptor, @NotNull Variance positionVariance) {
038            this.positionVariance = positionVariance;
039            this.typeParameterDescriptor = typeParameterDescriptor;
040            this.originalType = typeParameterDescriptor.getDefaultType();
041        }
042    
043        // Known type
044        public TypeValue(@NotNull JetType knownType) {
045            this.positionVariance = null;
046            this.typeParameterDescriptor = null;
047            this.originalType = knownType;
048            this.value = knownType;
049        }
050    
051        public boolean isKnown() {
052            return typeParameterDescriptor == null;
053        }
054    
055        public TypeParameterDescriptor getTypeParameterDescriptor() {
056            return typeParameterDescriptor;
057        }
058    
059        @NotNull
060        public Variance getPositionVariance() {
061            return positionVariance;
062        }
063    
064        @Override
065        @NotNull
066        public Set<TypeValue> getUpperBounds() {
067            return upperBounds;
068        }
069    
070        @Override
071        @NotNull
072        public Set<TypeValue> getLowerBounds() {
073            return lowerBounds;
074        }
075    
076        @NotNull
077        public JetType getType() {
078            return value;
079        }
080    
081        @NotNull
082        public JetType getOriginalType() {
083            return originalType;
084        }
085    
086        public void addUpperBound(@NotNull TypeValue bound) {
087            upperBounds.add(bound);
088        }
089    
090        public void addLowerBound(@NotNull TypeValue bound) {
091            lowerBounds.add(bound);
092        }
093    
094        public void setValue(@NotNull JetType value) {
095            this.value = value;
096        }
097    
098        public boolean hasValue() {
099            return value != null;
100        }
101    
102        @Override
103        public String toString() {
104            return isKnown() ? getType().toString() : (getTypeParameterDescriptor() + (hasValue() ? " |-> " + getType() : ""));
105        }
106    }