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.jet.lang.parsing;
018
019
020 import com.intellij.lang.PsiBuilder;
021 import com.intellij.lang.impl.PsiBuilderAdapter;
022 import com.intellij.psi.TokenType;
023 import com.intellij.psi.tree.IElementType;
024 import com.intellij.psi.tree.TokenSet;
025 import org.jetbrains.jet.lexer.JetTokens;
026
027 import com.intellij.util.containers.Stack;
028
029
030 import static org.jetbrains.jet.lexer.JetTokens.*;
031
032 public class SemanticWhitespaceAwarePsiBuilderImpl extends PsiBuilderAdapter implements SemanticWhitespaceAwarePsiBuilder {
033 private final TokenSet complexTokens = TokenSet.create(SAFE_ACCESS, ELVIS, EXCLEXCL);
034 private final Stack<Boolean> joinComplexTokens = new Stack<Boolean>();
035
036 private final Stack<Boolean> newlinesEnabled = new Stack<Boolean>();
037
038 public SemanticWhitespaceAwarePsiBuilderImpl(PsiBuilder delegate) {
039 super(delegate);
040 newlinesEnabled.push(true);
041 joinComplexTokens.push(true);
042 }
043
044 @Override
045 public boolean newlineBeforeCurrentToken() {
046 if (!newlinesEnabled.peek()) return false;
047
048 if (eof()) return true;
049
050 // TODO: maybe, memoize this somehow?
051 for (int i = 1; i <= getCurrentOffset(); i++) {
052 IElementType previousToken = rawLookup(-i);
053
054 if (previousToken == JetTokens.BLOCK_COMMENT
055 || previousToken == JetTokens.DOC_COMMENT
056 || previousToken == JetTokens.EOL_COMMENT
057 || previousToken == SHEBANG_COMMENT) {
058 continue;
059 }
060
061 if (previousToken != TokenType.WHITE_SPACE) {
062 break;
063 }
064
065 int previousTokenStart = rawTokenTypeStart(-i);
066 int previousTokenEnd = rawTokenTypeStart(-i + 1);
067
068 assert previousTokenStart >= 0;
069 assert previousTokenEnd < getOriginalText().length();
070
071 for (int j = previousTokenStart; j < previousTokenEnd; j++) {
072 if (getOriginalText().charAt(j) == '\n') {
073 return true;
074 }
075 }
076 }
077
078 return false;
079 }
080
081 @Override
082 public void disableNewlines() {
083 newlinesEnabled.push(false);
084 }
085
086 @Override
087 public void enableNewlines() {
088 newlinesEnabled.push(true);
089 }
090
091 @Override
092 public void restoreNewlinesState() {
093 assert newlinesEnabled.size() > 1;
094 newlinesEnabled.pop();
095 }
096
097 private boolean joinComplexTokens() {
098 return joinComplexTokens.peek();
099 }
100
101 @Override
102 public void restoreJoiningComplexTokensState() {
103 joinComplexTokens.pop();
104 }
105
106 @Override
107 public void enableJoiningComplexTokens() {
108 joinComplexTokens.push(true);
109 }
110
111 @Override
112 public void disableJoiningComplexTokens() {
113 joinComplexTokens.push(false);
114 }
115
116 @Override
117 public IElementType getTokenType() {
118 if (!joinComplexTokens()) return super.getTokenType();
119 return getJoinedTokenType(super.getTokenType(), 1);
120 }
121
122 private IElementType getJoinedTokenType(IElementType rawTokenType, int rawLookupSteps) {
123 if (rawTokenType == QUEST) {
124 IElementType nextRawToken = rawLookup(rawLookupSteps);
125 if (nextRawToken == DOT) return SAFE_ACCESS;
126 if (nextRawToken == COLON) return ELVIS;
127 }
128 else if (rawTokenType == EXCL) {
129 IElementType nextRawToken = rawLookup(rawLookupSteps);
130 if (nextRawToken == EXCL) return EXCLEXCL;
131 }
132 return rawTokenType;
133 }
134
135 @Override
136 public void advanceLexer() {
137 if (!joinComplexTokens()) {
138 super.advanceLexer();
139 return;
140 }
141 IElementType tokenType = getTokenType();
142 if (complexTokens.contains(tokenType)) {
143 Marker mark = mark();
144 super.advanceLexer();
145 super.advanceLexer();
146 mark.collapse(tokenType);
147 }
148 else {
149 super.advanceLexer();
150 }
151 }
152
153 @Override
154 public String getTokenText() {
155 if (!joinComplexTokens()) return super.getTokenText();
156 IElementType tokenType = getTokenType();
157 if (complexTokens.contains(tokenType)) {
158 if (tokenType == ELVIS) return "?:";
159 if (tokenType == SAFE_ACCESS) return "?.";
160 }
161 return super.getTokenText();
162 }
163
164 @Override
165 public IElementType lookAhead(int steps) {
166 if (!joinComplexTokens()) return super.lookAhead(steps);
167
168 if (complexTokens.contains(getTokenType())) {
169 return super.lookAhead(steps + 1);
170 }
171 return getJoinedTokenType(super.lookAhead(steps), 2);
172 }
173 }