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.expression.foreach;
018    
019    import com.google.common.collect.Lists;
020    import com.google.dart.compiler.backend.js.ast.*;
021    import org.jetbrains.annotations.NotNull;
022    import org.jetbrains.jet.lang.psi.JetBinaryExpression;
023    import org.jetbrains.jet.lang.psi.JetExpression;
024    import org.jetbrains.jet.lang.psi.JetForExpression;
025    import org.jetbrains.jet.lexer.JetTokens;
026    import org.jetbrains.k2js.translate.context.TemporaryVariable;
027    import org.jetbrains.k2js.translate.context.TranslationContext;
028    
029    import java.util.List;
030    
031    import static org.jetbrains.k2js.translate.utils.JsAstUtils.*;
032    import static org.jetbrains.k2js.translate.utils.PsiUtils.getLoopRange;
033    import static org.jetbrains.k2js.translate.utils.TemporariesUtils.temporariesInitialization;
034    import static org.jetbrains.k2js.translate.utils.TranslationUtils.translateLeftExpression;
035    import static org.jetbrains.k2js.translate.utils.TranslationUtils.translateRightExpression;
036    
037    
038    // TODO: implement reverse semantics
039    public final class RangeLiteralForTranslator extends ForTranslator {
040    
041        @NotNull
042        public static JsStatement doTranslate(@NotNull JetForExpression expression,
043                                              @NotNull TranslationContext context) {
044            return (new RangeLiteralForTranslator(expression, context).translate());
045        }
046    
047        public static boolean isApplicable(@NotNull JetForExpression expression,
048                                           @NotNull TranslationContext context) {
049            JetExpression loopRange = getLoopRange(expression);
050            if (!(loopRange instanceof JetBinaryExpression)) {
051                return false;
052            }
053            boolean isRangeToOperation = ((JetBinaryExpression) loopRange).getOperationToken() == JetTokens.RANGE;
054            return isRangeToOperation && RangeForTranslator.isApplicable(expression, context);
055        }
056    
057        @NotNull
058        private final JsExpression rangeStart;
059    
060        @NotNull
061        private final TemporaryVariable rangeEnd;
062    
063        private RangeLiteralForTranslator(@NotNull JetForExpression forExpression, @NotNull TranslationContext context) {
064            super(forExpression, context);
065            JetExpression loopRange = getLoopRange(expression);
066            assert loopRange instanceof JetBinaryExpression;
067            JetBinaryExpression loopRangeAsBinary = ((JetBinaryExpression) loopRange);
068            rangeStart = translateLeftExpression(context, loopRangeAsBinary);
069            rangeEnd = context.declareTemporary(getRangeEnd(loopRangeAsBinary));
070        }
071    
072        @NotNull
073        private JsExpression getRangeEnd(@NotNull JetBinaryExpression loopRangeAsBinary) {
074            JsExpression rightExpression = translateRightExpression(context(), loopRangeAsBinary);
075            return new JsBinaryOperation(JsBinaryOperator.ADD, rightExpression, program().getNumberLiteral(1));
076        }
077    
078        @NotNull
079        private JsBlock translate() {
080            List<JsStatement> blockStatements = Lists.newArrayList();
081            blockStatements.add(temporariesInitialization(rangeEnd).makeStmt());
082            blockStatements.add(generateForExpression(initExpression(),
083                                                      getCondition(),
084                                                      getIncrExpression(),
085                                                      translateOriginalBodyExpression()));
086            return new JsBlock(blockStatements);
087        }
088    
089        @NotNull
090        private JsVars initExpression() {
091            return newVar(parameterName, rangeStart);
092        }
093    
094        @NotNull
095        private JsExpression getCondition() {
096            return inequality(parameterName.makeRef(), rangeEnd.reference());
097        }
098    
099        @NotNull
100        private JsExpression getIncrExpression() {
101            return new JsPostfixOperation(JsUnaryOperator.INC, parameterName.makeRef());
102        }
103    }