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