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 com.google.dart.compiler.backend.js.ast.JsNumberLiteral;
023 import org.jetbrains.annotations.NotNull;
024 import org.jetbrains.annotations.Nullable;
025 import org.jetbrains.jet.lang.psi.*;
026 import org.jetbrains.jet.lang.resolve.name.Name;
027 import org.jetbrains.k2js.translate.context.TranslationContext;
028 import org.jetbrains.k2js.translate.general.AbstractTranslator;
029 import org.jetbrains.k2js.translate.general.Translation;
030
031 import static org.jetbrains.k2js.translate.utils.JsAstUtils.sum;
032 import static org.jetbrains.k2js.translate.utils.JsDescriptorUtils.getNameIfStandardType;
033
034
035 public final class StringTemplateTranslator extends AbstractTranslator {
036
037 @NotNull
038 public static JsExpression translate(@NotNull JetStringTemplateExpression expression,
039 @NotNull TranslationContext context) {
040 return (new StringTemplateTranslator(expression, context).translate());
041 }
042
043 @NotNull
044 private final JetStringTemplateExpression expression;
045
046 private StringTemplateTranslator(@NotNull JetStringTemplateExpression expression,
047 @NotNull TranslationContext context) {
048 super(context);
049 this.expression = expression;
050 }
051
052 @NotNull
053 private JsExpression translate() {
054 assert expression.getEntries().length != 0 : "String template must have one or more entries.";
055 EntryVisitor entryVisitor = new EntryVisitor();
056 for (JetStringTemplateEntry entry : expression.getEntries()) {
057 entry.accept(entryVisitor);
058 }
059 return entryVisitor.getResultingExpression();
060 }
061
062 private final class EntryVisitor extends JetVisitorVoid {
063
064 @Nullable
065 private JsExpression resultingExpression = null;
066
067 void append(@NotNull JsExpression expression) {
068 if (resultingExpression == null) {
069 resultingExpression = expression;
070 }
071 else {
072 resultingExpression = sum(resultingExpression, expression);
073 }
074 }
075
076 @Override
077 public void visitStringTemplateEntryWithExpression(@NotNull JetStringTemplateEntryWithExpression entry) {
078 JetExpression entryExpression = entry.getExpression();
079 assert entryExpression != null :
080 "JetStringTemplateEntryWithExpression must have not null entry expression.";
081 JsExpression translatedExpression = Translation.translateAsExpression(entryExpression, context());
082 if (translatedExpression instanceof JsNumberLiteral) {
083 append(context().program().getStringLiteral(translatedExpression.toString()));
084 return;
085 }
086 if (mustCallToString(entryExpression)) {
087 append(new JsInvocation(new JsNameRef("toString", translatedExpression)));
088 } else {
089 append(translatedExpression);
090 }
091 }
092
093 private boolean mustCallToString(@NotNull JetExpression entryExpression) {
094 Name typeName = getNameIfStandardType(entryExpression, context());
095 if (typeName == null) {
096 return true;
097 }
098 //TODO: this is a hacky optimization, should use some generic approach
099 if (typeName.asString().equals("String")) {
100 return false;
101 }
102 if (typeName.asString().equals("Int") && resultingExpression != null) {
103 return false;
104 }
105 return true;
106 }
107
108 @Override
109 public void visitLiteralStringTemplateEntry(@NotNull JetLiteralStringTemplateEntry entry) {
110 appendText(entry.getText());
111 }
112
113 @Override
114 public void visitEscapeStringTemplateEntry(@NotNull JetEscapeStringTemplateEntry entry) {
115 appendText(entry.getUnescapedValue());
116 }
117
118 private void appendText(@NotNull String text) {
119 append(program().getStringLiteral(text));
120 }
121
122 @NotNull
123 public JsExpression getResultingExpression() {
124 assert resultingExpression != null;
125 return resultingExpression;
126 }
127 }
128 }