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.*;
020    import com.intellij.openapi.util.Pair;
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                currentBlock.getStatements().add(vars);
062            }
063    
064            JsName temporaryName = currentScope.declareTemporary();
065            vars.add(new JsVar(temporaryName, null));
066            return TemporaryVariable.create(temporaryName, initExpression);
067        }
068    
069        //TODO: replace return type to make it more readable
070        @NotNull
071        public Pair<JsVar, JsExpression> createTemporary(@Nullable JsExpression initExpression) {
072            JsVar var = new JsVar(currentScope.declareTemporary(), initExpression);
073            return Pair.create(var, (JsExpression) new JsNameRef(var.getName()));
074        }
075    
076        @NotNull
077        public JsVar createTemporaryVar(@NotNull JsExpression initExpression) {
078            return new JsVar(currentScope.declareTemporary(), initExpression);
079        }
080    
081        @NotNull
082        public JsScope getScope() {
083            return currentScope;
084        }
085    
086        @NotNull
087        public JsBlock jsBlock() {
088            return currentBlock;
089        }
090    }