001    /*
002     * Copyright 2010-2015 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.kotlin.resolve.calls.results;
018    
019    import org.jetbrains.annotations.NotNull;
020    
021    import java.util.EnumSet;
022    
023    public enum ResolutionStatus {
024        UNKNOWN_STATUS,
025        UNSAFE_CALL_ERROR,
026        OTHER_ERROR,
027        // '1.foo()' shouldn't be resolved to 'fun String.foo()'
028        // candidates with such error are treated specially
029        // (are mentioned in 'unresolved' error, if there are no other options)
030        RECEIVER_TYPE_ERROR,
031        // 'a.foo()' shouldn't be resolved to package level non-extension 'fun foo()'
032        // candidates with such error are thrown away completely
033        RECEIVER_PRESENCE_ERROR,
034        INCOMPLETE_TYPE_INFERENCE,
035        SUCCESS(true);
036    
037        @SuppressWarnings("unchecked")
038        public static final EnumSet<ResolutionStatus>[] SEVERITY_LEVELS = new EnumSet[] {
039                EnumSet.of(UNSAFE_CALL_ERROR), // weakest
040                EnumSet.of(OTHER_ERROR),
041                EnumSet.of(RECEIVER_TYPE_ERROR),
042                EnumSet.of(RECEIVER_PRESENCE_ERROR), // most severe
043        };
044    
045        private final boolean success;
046        private int severityIndex = -1;
047    
048        private ResolutionStatus(boolean success) {
049            this.success = success;
050        }
051    
052        private ResolutionStatus() {
053            this(false);
054        }
055    
056        public boolean isSuccess() {
057            return success;
058        }
059    
060        @NotNull
061        public ResolutionStatus combine(ResolutionStatus other) {
062            if (this == UNKNOWN_STATUS) return other;
063            if (SUCCESS.among(this, other)) {
064                return SUCCESS.chooseDifferent(this, other);
065            }
066            if (INCOMPLETE_TYPE_INFERENCE.among(this, other)) {
067                return INCOMPLETE_TYPE_INFERENCE.chooseDifferent(this, other);
068            }
069            if (this.getSeverityIndex() < other.getSeverityIndex()) return other;
070            return this;
071        }
072    
073        private boolean among(ResolutionStatus first, ResolutionStatus second) {
074            return this == first || this == second;
075        }
076    
077        private ResolutionStatus chooseDifferent(ResolutionStatus first, ResolutionStatus second) {
078            assert among(first, second);
079            return this == first ? second : first;
080        }
081    
082        private int getSeverityIndex() {
083            if (severityIndex == -1) {
084                for (int i = 0; i < SEVERITY_LEVELS.length; i++) {
085                    if (SEVERITY_LEVELS[i].contains(this)) {
086                        severityIndex = i;
087                        break;
088                    }
089                }
090            }
091            assert severityIndex >= 0;
092    
093            return severityIndex;
094        }
095    }