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.smartcasts;
018    
019    import org.jetbrains.annotations.NotNull;
020    import org.jetbrains.annotations.Nullable;
021    import org.jetbrains.jet.lang.types.JetType;
022    import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
023    
024    public class DataFlowValue {
025        
026        public static final DataFlowValue NULL = new DataFlowValue(new Object(), KotlinBuiltIns.getInstance().getNullableNothingType(), false, Nullability.NULL);
027        public static final DataFlowValue NULLABLE = new DataFlowValue(new Object(), KotlinBuiltIns.getInstance().getNullableAnyType(), false, Nullability.UNKNOWN);
028    
029        private final boolean stableIdentifier;
030        private final JetType type;
031        private final Object id;
032        private final Nullability immanentNullability;
033    
034        // Use DataFlowValueFactory
035        /*package*/ DataFlowValue(Object id, JetType type, boolean stableIdentifier, Nullability immanentNullability) {
036            this.stableIdentifier = stableIdentifier;
037            this.type = type;
038            this.id = id;
039            this.immanentNullability = immanentNullability;
040        }
041    
042        @Nullable
043        public Object getId() {
044            return id;
045        }
046    
047        @NotNull
048        public Nullability getImmanentNullability() {
049            return immanentNullability;
050        }
051    
052        /**
053         * Stable identifier is a non-literal value that is statically known to be immutable
054         * @return
055         */
056        public boolean isStableIdentifier() {
057            return stableIdentifier;
058        }
059    
060        @NotNull
061        public JetType getType() {
062            return type;
063        }
064    
065        @Override
066        public boolean equals(Object o) {
067            if (this == o) return true;
068            if (o == null || getClass() != o.getClass()) return false;
069    
070            DataFlowValue that = (DataFlowValue) o;
071    
072            if (stableIdentifier != that.stableIdentifier) return false;
073            if (id != null ? !id.equals(that.id) : that.id != null) return false;
074            if (type != null ? !type.equals(that.type) : that.type != null) return false;
075    
076            return true;
077        }
078    
079        @Override
080        public String toString() {
081            return (stableIdentifier ? "stable " : "unstable ") + (id == null ? null : id.toString()) + " " + immanentNullability;
082        }
083    
084        @Override
085        public int hashCode() {
086            int result = (stableIdentifier ? 1 : 0);
087            result = 31 * result + (type != null ? type.hashCode() : 0);
088            result = 31 * result + (id != null ? id.hashCode() : 0);
089            return result;
090        }
091    }