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
017package org.jetbrains.k2js.translate.expression.foreach;
018
019import com.google.common.collect.Lists;
020import com.google.dart.compiler.backend.js.ast.*;
021import org.jetbrains.annotations.NotNull;
022import org.jetbrains.jet.lang.psi.JetBinaryExpression;
023import org.jetbrains.jet.lang.psi.JetExpression;
024import org.jetbrains.jet.lang.psi.JetForExpression;
025import org.jetbrains.jet.lexer.JetTokens;
026import org.jetbrains.k2js.translate.context.TemporaryVariable;
027import org.jetbrains.k2js.translate.context.TranslationContext;
028
029import java.util.List;
030
031import static org.jetbrains.k2js.translate.utils.JsAstUtils.*;
032import static org.jetbrains.k2js.translate.utils.PsiUtils.getLoopRange;
033import static org.jetbrains.k2js.translate.utils.TemporariesUtils.temporariesInitialization;
034import static org.jetbrains.k2js.translate.utils.TranslationUtils.translateLeftExpression;
035import static org.jetbrains.k2js.translate.utils.TranslationUtils.translateRightExpression;
036
037
038// TODO: implement reverse semantics
039public 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}