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;
018
019 import com.google.dart.compiler.backend.js.ast.JsExpression;
020 import com.google.dart.compiler.backend.js.ast.JsInvocation;
021 import com.google.dart.compiler.backend.js.ast.JsNameRef;
022 import org.jetbrains.annotations.NotNull;
023 import org.jetbrains.annotations.Nullable;
024 import org.jetbrains.jet.lang.descriptors.ClassDescriptor;
025 import org.jetbrains.jet.lang.psi.JetExpression;
026 import org.jetbrains.jet.lang.psi.JetIsExpression;
027 import org.jetbrains.jet.lang.psi.JetTypeReference;
028 import org.jetbrains.jet.lang.resolve.name.Name;
029 import org.jetbrains.k2js.translate.context.TranslationContext;
030 import org.jetbrains.k2js.translate.general.AbstractTranslator;
031 import org.jetbrains.k2js.translate.general.Translation;
032 import org.jetbrains.k2js.translate.intrinsic.functions.patterns.NamePredicate;
033 import org.jetbrains.k2js.translate.utils.BindingUtils;
034 import org.jetbrains.k2js.translate.utils.TranslationUtils;
035
036 import static org.jetbrains.k2js.translate.utils.BindingUtils.getTypeByReference;
037 import static org.jetbrains.k2js.translate.utils.JsAstUtils.*;
038 import static org.jetbrains.k2js.translate.utils.JsDescriptorUtils.getNameIfStandardType;
039
040 public final class PatternTranslator extends AbstractTranslator {
041
042 @NotNull
043 public static PatternTranslator newInstance(@NotNull TranslationContext context) {
044 return new PatternTranslator(context);
045 }
046
047 private PatternTranslator(@NotNull TranslationContext context) {
048 super(context);
049 }
050
051 @NotNull
052 public JsExpression translateIsExpression(@NotNull JetIsExpression expression) {
053 JsExpression left = Translation.translateAsExpression(expression.getLeftHandSide(), context());
054 JetTypeReference typeReference = expression.getTypeRef();
055 assert typeReference != null;
056 JsExpression result = translateIsCheck(left, typeReference);
057 if (expression.isNegated()) {
058 return negated(result);
059 }
060 return result;
061 }
062
063 @NotNull
064 public JsExpression translateIsCheck(@NotNull JsExpression subject, @NotNull JetTypeReference typeReference) {
065 JsExpression result = translateAsIntrinsicTypeCheck(subject, typeReference);
066 if (result != null) {
067 return result;
068 }
069 return translateAsIsCheck(subject, typeReference);
070 }
071
072 @NotNull
073 private JsExpression translateAsIsCheck(@NotNull JsExpression expressionToMatch,
074 @NotNull JetTypeReference typeReference) {
075 JsInvocation isCheck = new JsInvocation(context().namer().isOperationReference(),
076 expressionToMatch, getClassNameReference(typeReference));
077 if (isNullable(typeReference)) {
078 return addNullCheck(expressionToMatch, isCheck);
079 }
080 return isCheck;
081 }
082
083 @Nullable
084 private JsExpression translateAsIntrinsicTypeCheck(@NotNull JsExpression expressionToMatch,
085 @NotNull JetTypeReference typeReference) {
086 Name typeName = getNameIfStandardType(getTypeByReference(bindingContext(), typeReference));
087 if (typeName == null) {
088 return null;
089 }
090
091 String jsSTypeName;
092 if (NamePredicate.STRING.apply(typeName)) {
093 jsSTypeName = "string";
094 }
095 else if (NamePredicate.PRIMITIVE_NUMBERS.apply(typeName)) {
096 jsSTypeName = "number";
097 }
098 else {
099 return null;
100 }
101 return typeof(expressionToMatch, program().getStringLiteral(jsSTypeName));
102 }
103
104 @NotNull
105 private static JsExpression addNullCheck(@NotNull JsExpression expressionToMatch, @NotNull JsInvocation isCheck) {
106 return or(TranslationUtils.isNullCheck(expressionToMatch), isCheck);
107 }
108
109 private boolean isNullable(JetTypeReference typeReference) {
110 return getTypeByReference(bindingContext(), typeReference).isNullable();
111 }
112
113 @NotNull
114 private JsNameRef getClassNameReference(@NotNull JetTypeReference typeReference) {
115 ClassDescriptor referencedClass = BindingUtils.getClassDescriptorForTypeReference
116 (bindingContext(), typeReference);
117 return context().getQualifiedReference(referencedClass);
118 }
119
120 @NotNull
121 public JsExpression translateExpressionPattern(@NotNull JsExpression expressionToMatch, @NotNull JetExpression patternExpression) {
122 JsExpression expressionToMatchAgainst = translateExpressionForExpressionPattern(patternExpression);
123 return equality(expressionToMatch, expressionToMatchAgainst);
124 }
125
126 @NotNull
127 public JsExpression translateExpressionForExpressionPattern(@NotNull JetExpression patternExpression) {
128 return Translation.translateAsExpression(patternExpression, context());
129 }
130 }