javacc xxxTokenManager類作用 以及重要方法解析

/* Generated By:JavaCC: Do not edit this line. QueryParserTokenManager.java */
import java.io.StringReader;
/** 
 *@ summary xxxTokenManager重要方法介紹
 *@ xxxTokenManager類根據詞法狀态和截取字元竄并生成不同類型的token對象
 *  提供給xxxParser類進行文法分析,xxxParser通過jj_consume_token(token_kind);
 *  方法進行消費指定的token然後xxxParser有xxxTokenManager對象的引用可以拿到
 *  通過調用xxxTokenManager.getNextToken()方法得到下一個應該出現的字元對象
 *  如果記号管理器傳回的token對象和需要的token對象類型不統一說明字元竄
 *  有文法錯誤
 */
/** Token Manager. */
public class QueryParserTokenManager implements QueryParserConstants
{

  /** 輸出調試資訊的輸出流. */
  public static  java.io.PrintStream debugStream = System.out;
  /** 設定調試輸出流. */
  public static  void setDebugStream(java.io.PrintStream ds) { debugStream = ds; }
  // ...
static final int[] jjnextStates = {
};

/** 目前在Token或Special_Token中定義的詞法狀态名字數組*/
/** Lexer state names. */
public static final String[] lexStateNames = {
   "DEFAULT",
   "IN_SINGLE_LINE_COMMENT",
   "IN_FORMAL_COMMENT",
   "IN_MULTI_LINE_COMMENT",
};

/** Lex State array. */
public static final int[] jjnewLexState = {
   -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, 3, 0, 0, 0, -1, -1, 
};
static final long[] jjtoToken = {
   0x101e1L, 
};
static final long[] jjtoSkip = {
   0x701eL, 
};
static final long[] jjtoSpecial = {
   0x7000L, 
};
static final long[] jjtoMore = {
   0x8e00L, 
};
static protected SimpleCharStream input_stream;/** 使用者輸入的字元竄位元組流*/
static private final int[] jjrounds = new int[4];
static private final int[] jjstateSet = new int[8];
private static final StringBuilder jjimage = new StringBuilder();
private static StringBuilder image = jjimage;
private static int jjimageLen;
private static int lengthOfMatch;
static protected char curChar;
/** Constructor. */
public QueryParserTokenManager(SimpleCharStream stream){
   if (input_stream != null)
      throw new TokenMgrError("ERROR: Second call to constructor of static lexer. You must use ReInit() to initialize the static variables.", TokenMgrError.STATIC_LEXER_ERROR);
   input_stream = stream;
}

/** Constructor. */
public QueryParserTokenManager(SimpleCharStream stream, int lexState){
   this(stream);
   SwitchTo(lexState);
}

/** Reinitialise parser. */
static public void ReInit(SimpleCharStream stream)
{
   jjmatchedPos = jjnewStateCnt = 0;
   curLexState = defaultLexState;
   input_stream = stream;
   ReInitRounds();
}

/** 将目前token對象補充完整*/
static protected Token jjFillToken()
{
   final Token t;
   final String curTokenImage;
   final int beginLine;
   final int endLine;
   final int beginColumn;
   final int endColumn;
   String im = jjstrLiteralImages[jjmatchedKind];
   curTokenImage = (im == null) ? input_stream.GetImage() : im;
   beginLine = input_stream.getBeginLine();
   beginColumn = input_stream.getBeginColumn();
   endLine = input_stream.getEndLine();
   endColumn = input_stream.getEndColumn();
   t = Token.newToken(jjmatchedKind, curTokenImage);

   t.beginLine = beginLine;
   t.endLine = endLine;
   t.beginColumn = beginColumn;
   t.endColumn = endColumn;

   return t;
}

static int curLexState = 0;
static int defaultLexState = 0;
static int jjnewStateCnt;
static int jjround;
static int jjmatchedPos;
static int jjmatchedKind;

/** Get the next Token. */
/** 記号管理器如何生成token*/
public static Token getNextToken() 
{
  Token specialToken = null;/** 在比對過程中可以生成的特殊記号*/
  Token matchedToken; /** 比對到的記号*/
  int curPos = 0;

  EOFLoop :
  for (;;)
  {
   try
   {
      curChar = input_stream.BeginToken();/** 從輸入的位元組流中讀取一個字元*/
   }
   catch(java.io.IOException e)
   {
      jjmatchedKind = 0;
      matchedToken = jjFillToken();
      matchedToken.specialToken = specialToken;
      return matchedToken;
   }

   image = jjimage;
   image.setLength(0);
   jjimageLen = 0;
   

   for (;;)
   {
     switch(curLexState)/**根據詞法狀态找到目前字元所對應的token_kind類型 */
     {
       case 0:/** 預設的詞法狀态*/
         try { 
		    input_stream.backup(0);
            while (curChar <= 32 && (0x100002600L & (1L << curChar)) != 0L)
               curChar = input_stream.BeginToken();
         }
         catch (java.io.IOException e1) { 
			 continue EOFLoop; 
		 }

         jjmatchedKind = 0x7fffffff;
         jjmatchedPos = 0;
         curPos = jjMoveStringLiteralDfa0_0();
         break;
       case 1:
         jjmatchedKind = 0x7fffffff;
         jjmatchedPos = 0;
         curPos = jjMoveStringLiteralDfa0_1();
         if (jjmatchedPos == 0 && jjmatchedKind > 15)
         {
            jjmatchedKind = 15;
         }
         break;
       case 2:
         jjmatchedKind = 0x7fffffff;
         jjmatchedPos = 0;
         curPos = jjMoveStringLiteralDfa0_2();
         if (jjmatchedPos == 0 && jjmatchedKind > 15)
         {
            jjmatchedKind = 15;
         }
         break;
       case 3:
         jjmatchedKind = 0x7fffffff;
         jjmatchedPos = 0;
         curPos = jjMoveStringLiteralDfa0_3();
         if (jjmatchedPos == 0 && jjmatchedKind > 15)
         {
            jjmatchedKind = 15;
         }
         break;
     }


     if (jjmatchedKind != 0x7fffffff)
     {
        if (jjmatchedPos + 1 < curPos)
           input_stream.backup(curPos - jjmatchedPos - 1);
        if ((jjtoToken[jjmatchedKind >> 6] & (1L << (jjmatchedKind & 077))) != 0L)
        {
           matchedToken = jjFillToken();
           matchedToken.specialToken = specialToken;/** 如果有特殊字元就儲存到token對象的specialtoken屬性中*/
       if (jjnewLexState[jjmatchedKind] != -1)
         curLexState = jjnewLexState[jjmatchedKind];
           return matchedToken;
        }
        else if ((jjtoSkip[jjmatchedKind >> 6] & (1L << (jjmatchedKind & 077))) != 0L)
        {
           if ((jjtoSpecial[jjmatchedKind >> 6] & (1L << (jjmatchedKind & 077))) != 0L)
           {
              matchedToken = jjFillToken();
              if (specialToken == null)
                 specialToken = matchedToken;
              else
              {
                 matchedToken.specialToken = specialToken;
                 specialToken = (specialToken.next = matchedToken);
              }
              SkipLexicalActions(matchedToken);/** 忽略跳過指定的字元*/
           }
           else
              SkipLexicalActions(null);
         if (jjnewLexState[jjmatchedKind] != -1)
           curLexState = jjnewLexState[jjmatchedKind];
           continue EOFLoop;
        }
        /** 處理更多這樣的字元的方法*/
        MoreLexicalActions();

      if (jjnewLexState[jjmatchedKind] != -1)
        curLexState = jjnewLexState[jjmatchedKind];
        curPos = 0;
        jjmatchedKind = 0x7fffffff;
        try {
           curChar = input_stream.readChar();
           continue;
        }
        catch (java.io.IOException e1) { }
     }
     int error_line = input_stream.getEndLine();
     int error_column = input_stream.getEndColumn();
     String error_after = null;
     boolean EOFSeen = false;
     try { input_stream.readChar(); input_stream.backup(1); }
     catch (java.io.IOException e1) {
        EOFSeen = true;
        error_after = curPos <= 1 ? "" : input_stream.GetImage();
        if (curChar == '\n' || curChar == '\r') {
           error_line++;
           error_column = 0;
        }
        else
           error_column++;
     }
     if (!EOFSeen) {
        input_stream.backup(1);
        error_after = curPos <= 1 ? "" : input_stream.GetImage();
     }
     throw new TokenMgrError(EOFSeen, curLexState, error_line, error_column, error_after, curChar, TokenMgrError.LEXICAL_ERROR);
   }
  }
}

/** 忽略的字元需要調用的方法 */
static void SkipLexicalActions(Token matchedToken)
{
   switch(jjmatchedKind)
   {
      default :
         break;
   }
}
/** 更多這樣的單詞處理 */
static void MoreLexicalActions()
{
   jjimageLen += (lengthOfMatch = jjmatchedPos + 1);
   switch(jjmatchedKind)
   {
      case 10 :
         image.append(input_stream.GetSuffix(jjimageLen));
         jjimageLen = 0;
                   input_stream.backup(1);
         break;
      default :
         break;
   }
}

}