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.operation;
018
019 import com.google.common.collect.Lists;
020 import com.google.dart.compiler.backend.js.ast.JsBinaryOperation;
021 import com.google.dart.compiler.backend.js.ast.JsBinaryOperator;
022 import com.google.dart.compiler.backend.js.ast.JsExpression;
023 import com.google.dart.compiler.util.AstUtil;
024 import org.jetbrains.annotations.NotNull;
025 import org.jetbrains.jet.lang.psi.JetExpression;
026 import org.jetbrains.jet.lang.psi.JetUnaryExpression;
027 import org.jetbrains.jet.lang.types.expressions.OperatorConventions;
028 import org.jetbrains.k2js.translate.context.TemporaryVariable;
029 import org.jetbrains.k2js.translate.context.TranslationContext;
030 import org.jetbrains.k2js.translate.general.AbstractTranslator;
031 import org.jetbrains.k2js.translate.reference.CachedAccessTranslator;
032
033 import java.util.List;
034
035 import static org.jetbrains.k2js.translate.reference.AccessTranslationUtils.getCachedAccessTranslator;
036 import static org.jetbrains.k2js.translate.utils.JsAstUtils.newSequence;
037 import static org.jetbrains.k2js.translate.utils.PsiUtils.*;
038 import static org.jetbrains.k2js.translate.utils.TemporariesUtils.temporariesInitialization;
039 import static org.jetbrains.k2js.translate.utils.TranslationUtils.hasCorrespondingFunctionIntrinsic;
040
041 // TODO: provide better increment translator logic
042 public abstract class IncrementTranslator extends AbstractTranslator {
043
044 public static boolean isIncrement(@NotNull JetUnaryExpression expression) {
045 return OperatorConventions.INCREMENT_OPERATIONS.contains(getOperationToken(expression));
046 }
047
048 @NotNull
049 public static JsExpression translate(@NotNull JetUnaryExpression expression,
050 @NotNull TranslationContext context) {
051 if (hasCorrespondingFunctionIntrinsic(context, expression)) {
052 return IntrinsicIncrementTranslator.doTranslate(expression, context);
053 }
054 return (new OverloadedIncrementTranslator(expression, context)).translateIncrementExpression();
055 }
056
057 @NotNull
058 protected final JetUnaryExpression expression;
059 @NotNull
060 protected final CachedAccessTranslator accessTranslator;
061
062 protected IncrementTranslator(@NotNull JetUnaryExpression expression,
063 @NotNull TranslationContext context) {
064 super(context);
065 this.expression = expression;
066 JetExpression baseExpression = getBaseExpression(expression);
067 this.accessTranslator = getCachedAccessTranslator(baseExpression, context());
068 }
069
070 @NotNull
071 protected JsExpression translateIncrementExpression() {
072 return withTemporariesInitialized(doTranslateIncrementExpression());
073 }
074
075 @NotNull
076 private JsExpression doTranslateIncrementExpression() {
077 if (isPrefix(expression)) {
078 return asPrefix();
079 }
080 return asPostfix();
081 }
082
083 //TODO: decide if this expression can be optimised in case of direct access (not property)
084 @NotNull
085 private JsExpression asPrefix() {
086 // code fragment: expr(a++)
087 // generate: expr(a = a.inc(), a)
088 JsExpression getExpression = accessTranslator.translateAsGet();
089 JsExpression reassignment = variableReassignment(getExpression);
090 JsExpression getNewValue = accessTranslator.translateAsGet();
091 return new JsBinaryOperation(JsBinaryOperator.COMMA, reassignment, getNewValue);
092 }
093
094 //TODO: decide if this expression can be optimised in case of direct access (not property)
095 @NotNull
096 private JsExpression asPostfix() {
097 // code fragment: expr(a++)
098 // generate: expr( (t1 = a, t2 = t1, a = t1.inc(), t2) )
099 TemporaryVariable t1 = context().declareTemporary(accessTranslator.translateAsGet());
100 TemporaryVariable t2 = context().declareTemporary(t1.reference());
101 JsExpression variableReassignment = variableReassignment(t1.reference());
102 return AstUtil.newSequence(t1.assignmentExpression(), t2.assignmentExpression(),
103 variableReassignment, t2.reference());
104 }
105
106 @NotNull
107 private JsExpression variableReassignment(@NotNull JsExpression toCallMethodUpon) {
108 JsExpression overloadedMethodCallOnPropertyGetter = operationExpression(toCallMethodUpon);
109 return accessTranslator.translateAsSet(overloadedMethodCallOnPropertyGetter);
110 }
111
112 @NotNull
113 private JsExpression withTemporariesInitialized(@NotNull JsExpression expression) {
114 List<TemporaryVariable> temporaries = accessTranslator.declaredTemporaries();
115 List<JsExpression> expressions = Lists.newArrayList(temporariesInitialization(temporaries));
116 expressions.add(expression);
117 return newSequence(expressions);
118 }
119
120 @NotNull
121 abstract JsExpression operationExpression(@NotNull JsExpression receiver);
122 }