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.utils.mutator;
018    
019    import com.google.dart.compiler.backend.js.ast.*;
020    import org.jetbrains.annotations.NotNull;
021    
022    import java.util.List;
023    
024    import static org.jetbrains.kotlin.js.translate.utils.JsAstUtils.convertToStatement;
025    
026    public final class LastExpressionMutator {
027        public static JsStatement mutateLastExpression(@NotNull JsNode node, @NotNull Mutator mutator) {
028            return convertToStatement(new LastExpressionMutator(mutator).apply(node));
029        }
030    
031        @NotNull
032        private final Mutator mutator;
033    
034        private LastExpressionMutator(@NotNull Mutator mutator) {
035            this.mutator = mutator;
036        }
037    
038        //TODO: visitor?
039        //TODO: when expression?
040        @NotNull
041        private JsNode apply(@NotNull JsNode node) {
042            if (node instanceof JsBlock) {
043                return applyToBlock((JsBlock) node);
044            }
045            if (node instanceof JsIf) {
046                return applyToIf((JsIf) node);
047            }
048            if (node instanceof JsTry) {
049                return applyToTry((JsTry) node);
050            }
051            if (node instanceof JsExpressionStatement) {
052                return applyToStatement((JsExpressionStatement) node);
053            }
054            return mutator.mutate(node);
055        }
056    
057        @NotNull
058        private JsNode applyToStatement(@NotNull JsExpressionStatement node) {
059            return convertToStatement(apply(node.getExpression()));
060        }
061    
062        @NotNull
063        private JsNode applyToIf(@NotNull JsIf node) {
064            node.setThenStatement(convertToStatement(apply(node.getThenStatement())));
065            JsStatement elseStmt = node.getElseStatement();
066            if (elseStmt != null) {
067                node.setElseStatement(convertToStatement(apply(elseStmt)));
068            }
069            return node;
070        }
071    
072        @NotNull
073        private JsNode applyToTry(@NotNull JsTry node) {
074            applyToBlock(node.getTryBlock());
075            for(JsCatch jsCatch: node.getCatches()) {
076                applyToBlock(jsCatch.getBody());
077            }
078            return node;
079        }
080    
081        @NotNull
082        private JsNode applyToBlock(@NotNull JsBlock node) {
083            List<JsStatement> statements = node.getStatements();
084    
085            if (statements.isEmpty()) return node;
086    
087            int size = statements.size();
088            statements.set(size - 1, convertToStatement(apply(statements.get(size - 1))));
089            return node;
090        }
091    }