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