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 com.google.dart.compiler.backend.js.ast.*;
020    import com.google.dart.compiler.backend.js.ast.metadata.MetadataProperties;
021    import org.jetbrains.annotations.NotNull;
022    import org.jetbrains.annotations.Nullable;
023    
024    import static com.google.dart.compiler.backend.js.ast.JsVars.JsVar;
025    
026    //TODO: consider renaming to scoping context
027    public final class DynamicContext {
028        @NotNull
029        public static DynamicContext rootContext(@NotNull JsScope rootScope, @NotNull JsBlock globalBlock) {
030            return new DynamicContext(rootScope, globalBlock);
031        }
032    
033        @NotNull
034        public static DynamicContext newContext(@NotNull JsScope scope, @NotNull JsBlock block) {
035            return new DynamicContext(scope, block);
036        }
037    
038        @NotNull
039        private final JsScope currentScope;
040    
041        @NotNull
042        private final JsBlock currentBlock;
043    
044        @Nullable
045        private JsVars vars;
046    
047        private DynamicContext(@NotNull JsScope scope, @NotNull JsBlock block) {
048            this.currentScope = scope;
049            this.currentBlock = block;
050        }
051    
052        @NotNull
053        public DynamicContext innerBlock(@NotNull JsBlock block) {
054            return new DynamicContext(currentScope, block);
055        }
056    
057        @NotNull
058        public TemporaryVariable declareTemporary(@Nullable JsExpression initExpression) {
059            if (vars == null) {
060                vars = new JsVars();
061                MetadataProperties.setSynthetic(vars, true);
062                currentBlock.getStatements().add(vars);
063            }
064    
065            JsName temporaryName = currentScope.declareTemporary();
066            JsVar var = new JsVar(temporaryName, null);
067            MetadataProperties.setSynthetic(var, true);
068            vars.add(var);
069            return TemporaryVariable.create(temporaryName, initExpression);
070        }
071    
072        void moveVarsFrom(@NotNull DynamicContext dynamicContext) {
073            if (dynamicContext.vars != null) {
074                if (vars == null) {
075                    vars = dynamicContext.vars;
076                    currentBlock.getStatements().add(vars);
077                } else {
078                    vars.addAll(dynamicContext.vars);
079                }
080                dynamicContext.currentBlock.getStatements().remove(dynamicContext.vars);
081                dynamicContext.vars = null;
082            }
083        }
084    
085        @NotNull
086        public JsScope getScope() {
087            return currentScope;
088        }
089    
090        @NotNull
091        public JsBlock jsBlock() {
092            return currentBlock;
093        }
094    }