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.js.translate.context;
018    
019    import org.jetbrains.kotlin.js.backend.ast.JsExpression;
020    import org.jetbrains.annotations.NotNull;
021    import org.jetbrains.annotations.Nullable;
022    import org.jetbrains.kotlin.descriptors.DeclarationDescriptor;
023    import org.jetbrains.kotlin.psi.KtExpression;
024    
025    import java.util.Collections;
026    import java.util.Map;
027    
028    public class AliasingContext {
029        @NotNull
030        public static AliasingContext getCleanContext() {
031            return new AliasingContext(null, null, null);
032        }
033    
034        @Nullable
035        private final Map<DeclarationDescriptor, JsExpression> aliasesForDescriptors;
036    
037        @Nullable
038        private final Map<KtExpression, JsExpression> aliasesForExpressions;
039    
040        @Nullable
041        private final AliasingContext parent;
042    
043        private AliasingContext(
044                @Nullable AliasingContext parent,
045                @Nullable Map<DeclarationDescriptor, JsExpression> aliasesForDescriptors,
046                @Nullable Map<KtExpression, JsExpression> aliasesForExpressions
047        ) {
048            this.parent = parent;
049            this.aliasesForDescriptors = aliasesForDescriptors;
050            this.aliasesForExpressions = aliasesForExpressions;
051        }
052    
053        @NotNull
054        public AliasingContext inner() {
055            return new AliasingContext(this, null, null);
056        }
057    
058        @NotNull
059        public AliasingContext inner(@NotNull DeclarationDescriptor descriptor, @NotNull JsExpression alias) {
060            return new AliasingContext(this, Collections.singletonMap(descriptor, alias), null);
061        }
062    
063        @NotNull
064        public AliasingContext withExpressionsAliased(@NotNull Map<KtExpression, JsExpression> aliasesForExpressions) {
065            return new AliasingContext(this, null, aliasesForExpressions);
066        }
067    
068        @NotNull
069        public AliasingContext withDescriptorsAliased(@NotNull Map<DeclarationDescriptor, JsExpression> aliases) {
070            return new AliasingContext(this, aliases, null);
071        }
072    
073        @Nullable
074        public JsExpression getAliasForDescriptor(@NotNull DeclarationDescriptor descriptor) {
075            // these aliases cannot be shared and applicable only in current context
076            JsExpression alias = aliasesForDescriptors != null ? aliasesForDescriptors.get(descriptor.getOriginal()) : null;
077            return alias != null || parent == null ? alias : parent.getAliasForDescriptor(descriptor);
078        }
079    
080        @Nullable
081        public JsExpression getAliasForExpression(@NotNull KtExpression element) {
082            JsExpression alias = aliasesForExpressions != null ? aliasesForExpressions.get(element) : null;
083            return alias != null || parent == null ? alias : parent.getAliasForExpression(element);
084        }
085    }