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.JetExpression;
023    import org.jetbrains.jet.lang.psi.JetForExpression;
024    import org.jetbrains.jet.lang.types.JetType;
025    import org.jetbrains.k2js.translate.context.TemporaryVariable;
026    import org.jetbrains.k2js.translate.context.TranslationContext;
027    import org.jetbrains.k2js.translate.general.Translation;
028    import org.jetbrains.k2js.translate.intrinsic.functions.factories.CompositeFIF;
029    import org.jetbrains.k2js.translate.utils.BindingUtils;
030    
031    import java.util.Collections;
032    import java.util.List;
033    
034    import static org.jetbrains.jet.lang.resolve.DescriptorUtils.getClassDescriptorForType;
035    import static org.jetbrains.k2js.translate.utils.JsAstUtils.*;
036    import static org.jetbrains.k2js.translate.utils.PsiUtils.getLoopRange;
037    import static org.jetbrains.k2js.translate.utils.TemporariesUtils.temporariesInitialization;
038    
039    public final class ArrayForTranslator extends ForTranslator {
040    
041        @NotNull
042        public static JsStatement doTranslate(@NotNull JetForExpression expression,
043                @NotNull TranslationContext context) {
044            return (new ArrayForTranslator(expression, context).translate());
045        }
046    
047        public static boolean isApplicable(@NotNull JetForExpression expression,
048                @NotNull TranslationContext context) {
049            JetExpression loopRange = getLoopRange(expression);
050            JetType rangeType = BindingUtils.getTypeForExpression(context.bindingContext(), loopRange);
051            //TODO: better check
052            //TODO: IMPORTANT!
053            return getClassDescriptorForType(rangeType).getName().asString().equals("Array")
054                   || getClassDescriptorForType(rangeType).getName().asString().equals("IntArray");
055        }
056    
057        @NotNull
058        private final TemporaryVariable loopRange;
059    
060        @NotNull
061        private final TemporaryVariable end;
062    
063        @NotNull
064        private final TemporaryVariable index;
065    
066        private ArrayForTranslator(@NotNull JetForExpression forExpression, @NotNull TranslationContext context) {
067            super(forExpression, context);
068            loopRange = context.declareTemporary(Translation.translateAsExpression(getLoopRange(expression), context));
069    
070            JsExpression length = CompositeFIF.LENGTH_PROPERTY_INTRINSIC.apply(loopRange.reference(),
071                                                                        Collections.<JsExpression>emptyList(),
072                                                                        context());
073            end = context().declareTemporary(length);
074            index = context().declareTemporary(program().getNumberLiteral(0));
075        }
076    
077        @NotNull
078        private JsBlock translate() {
079            List<JsStatement> blockStatements = Lists.newArrayList();
080            blockStatements.add(temporariesInitialization(loopRange, end).makeStmt());
081            blockStatements.add(generateForExpression(getInitExpression(), getCondition(), getIncrementExpression(), getBody()));
082            return new JsBlock(blockStatements);
083        }
084    
085    
086        @NotNull
087        private JsStatement getBody() {
088            JsArrayAccess arrayAccess = new JsArrayAccess(loopRange.reference(), index.reference());
089            JsStatement currentVar = newVar(parameterName, arrayAccess);
090            JsStatement realBody = translateOriginalBodyExpression();
091            return new JsBlock(currentVar, realBody);
092        }
093    
094        @NotNull
095        private JsVars getInitExpression() {
096            return newVar(index.name(), program().getNumberLiteral(0));
097        }
098    
099        @NotNull
100        private JsExpression getCondition() {
101            return inequality(index.reference(), end.reference());
102        }
103    
104        @NotNull
105        private JsExpression getIncrementExpression() {
106            return new JsPrefixOperation(JsUnaryOperator.INC, index.reference());
107        }
108    }