java/java-impl/src/com/intellij/psi/impl/source/parsing/WhiteSpaceAndCommentsProcessor.java

   1 /*
   2  * Copyright 2000-2009 JetBrains s.r.o.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package com.intellij.psi.impl.source.parsing;
  17
  18 import com.intellij.psi.tree.TokenSet;
  19 import com.intellij.psi.tree.IElementType;
  20 import com.intellij.psi.impl.source.tree.StdTokenSets;
  21 import com.intellij.psi.impl.source.tree.TreeElement;
  22 import com.intellij.psi.impl.source.ParsingContext;
  23 import com.intellij.lexer.Lexer;
  24 import com.intellij.openapi.diagnostic.Logger;
  25
  26 public class WhiteSpaceAndCommentsProcessor implements TokenProcessor {
  27   private static final Logger LOG = Logger.getInstance("#com.intellij.psi.impl.source.parsing.WhiteSpaceAndCommentsProcessor");
  28
  29   public static final TokenProcessor INSTANCE = new WhiteSpaceAndCommentsProcessor();
  30   private final TokenSet myWhitespaceSet;
  31
  32   public WhiteSpaceAndCommentsProcessor() {
  33     this(StdTokenSets.WHITE_SPACE_OR_COMMENT_BIT_SET);
  34   }
  35
  36   public WhiteSpaceAndCommentsProcessor(TokenSet whitespaceSet) {
  37     myWhitespaceSet = whitespaceSet;
  38   }
  39
  40   public TreeElement process(Lexer lexer, ParsingContext context) {
  41     TreeElement first = null;
  42     TreeElement last = null;
  43     while (isTokenValid(lexer.getTokenType())) {
  44       TreeElement tokenElement = createToken(lexer, context);
  45       IElementType type = lexer.getTokenType();
  46       if (!myWhitespaceSet.contains(type)) {
  47         LOG.error("Missed token should be white space or comment:" + tokenElement);
  48         throw new RuntimeException();
  49       }
  50       if (last != null) {
  51         last.setTreeNext(tokenElement);
  52         tokenElement.setTreePrev(last);
  53         last = tokenElement;
  54       }
  55       else {
  56         first = last = tokenElement;
  57       }
  58       lexer.advance();
  59     }
  60     return first;
  61   }
  62
  63   protected TreeElement createToken(final Lexer lexer, final ParsingContext context) {
  64     return ParseUtil.createTokenElement(lexer, context.getCharTable());
  65   }
  66
  67   public boolean isTokenValid(IElementType tokenType) {
  68     return tokenType != null && myWhitespaceSet.contains(tokenType);
  69   }
  70 }