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.k2js.translate.context;
018
019 import com.google.dart.compiler.backend.js.ast.JsExpression;
020 import com.google.dart.compiler.backend.js.ast.JsName;
021 import gnu.trove.THashMap;
022 import org.jetbrains.annotations.NotNull;
023 import org.jetbrains.annotations.Nullable;
024 import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
025 import org.jetbrains.jet.lang.psi.JetExpression;
026
027 import java.util.Collections;
028 import java.util.Map;
029
030 public class AliasingContext {
031 private static final AliasingContext ROOT = new AliasingContext(null) {
032 @Override
033 protected JsExpression getAliasForDescriptor(@NotNull DeclarationDescriptor descriptor, boolean fromChild) {
034 return null;
035 }
036
037 @Override
038 public JsName getAliasForExpression(@NotNull JetExpression element) {
039 return null;
040 }
041
042 @Override
043 public void registerAlias(@NotNull DeclarationDescriptor descriptor, @NotNull JsExpression alias) {
044 throw new IllegalStateException();
045 }
046 };
047
048 public static AliasingContext getCleanContext() {
049 return new AliasingContext(ROOT);
050 }
051
052 @Nullable
053 private Map<DeclarationDescriptor, JsExpression> aliasesForDescriptors;
054
055 @Nullable
056 private final Map<JetExpression, JsName> aliasesForExpressions;
057
058 @Nullable
059 private final AliasingContext parent;
060
061 /*package*/ AliasingContext(@Nullable AliasingContext parent) {
062 this(parent, null, null);
063 }
064
065 private AliasingContext(
066 @Nullable AliasingContext parent,
067 @Nullable Map<DeclarationDescriptor, JsExpression> aliasesForDescriptors,
068 @Nullable Map<JetExpression, JsName> aliasesForExpressions
069 ) {
070 this.parent = parent;
071 this.aliasesForDescriptors = aliasesForDescriptors;
072 this.aliasesForExpressions = aliasesForExpressions;
073 }
074
075 @NotNull
076 public AliasingContext inner(@NotNull DeclarationDescriptor descriptor, @NotNull JsExpression alias) {
077 return new AliasingContext(this, Collections.singletonMap(descriptor, alias), null);
078 }
079
080 @NotNull
081 public AliasingContext notShareableThisAliased(@NotNull final DeclarationDescriptor thisDescriptor, @NotNull final JsExpression alias) {
082 return new AliasingContext(this) {
083 @Nullable
084 @Override
085 protected JsExpression getAliasForDescriptor(@NotNull DeclarationDescriptor descriptor, boolean fromChild) {
086 if (!fromChild && thisDescriptor == descriptor) {
087 return alias;
088 }
089 return super.getAliasForDescriptor(descriptor, fromChild);
090 }
091 };
092 }
093
094 @NotNull
095 public AliasingContext withExpressionsAliased(@NotNull Map<JetExpression, JsName> aliasesForExpressions) {
096 return new AliasingContext(this, null, aliasesForExpressions);
097 }
098
099 @NotNull
100 public AliasingContext withDescriptorsAliased(@NotNull Map<DeclarationDescriptor, JsExpression> aliases) {
101 return new AliasingContext(this, aliases, null);
102 }
103
104
105 @Nullable
106 public JsExpression getAliasForDescriptor(@NotNull DeclarationDescriptor descriptor) {
107 // these aliases cannot be shared and applicable only in current context
108 return getAliasForDescriptor(descriptor, false);
109 }
110
111 @Nullable
112 protected JsExpression getAliasForDescriptor(@NotNull DeclarationDescriptor descriptor, boolean fromChild) {
113 JsExpression alias = aliasesForDescriptors == null ? null : aliasesForDescriptors.get(descriptor.getOriginal());
114 return alias != null || parent == null ? alias : parent.getAliasForDescriptor(descriptor, true);
115 }
116
117 @Nullable
118 public JsName getAliasForExpression(@NotNull JetExpression element) {
119 JsName alias = aliasesForExpressions == null ? null : aliasesForExpressions.get(element);
120 return alias != null || parent == null ? alias : parent.getAliasForExpression(element);
121 }
122
123 /**
124 * Usages:
125 * 1) Local variable captured in closure. If captured in closure, any modification in closure should affect captured variable.
126 * So, "var count = n" wrapped as "var count = {v: n}". descriptor wil be property descriptor, alias will be JsObjectLiteral
127 *
128 * 2) Local named function.
129 */
130 public void registerAlias(@NotNull DeclarationDescriptor descriptor, @NotNull JsExpression alias) {
131 if (aliasesForDescriptors == null) {
132 aliasesForDescriptors = Collections.singletonMap(descriptor, alias);
133 }
134 else {
135 if (aliasesForDescriptors.size() == 1) {
136 Map<DeclarationDescriptor, JsExpression> singletonMap = aliasesForDescriptors;
137 aliasesForDescriptors = new THashMap<DeclarationDescriptor, JsExpression>();
138 aliasesForDescriptors.put(singletonMap.keySet().iterator().next(), singletonMap.values().iterator().next());
139 }
140 JsExpression prev = aliasesForDescriptors.put(descriptor, alias);
141 assert prev == null;
142 }
143 }
144 }