minijool.java

SkipOOMiniJOOL教学语言的编译器前端

  /**
   * Enters a new lexical state
   *
   * @param newState the new lexical state
   */
  public final void yybegin(int newState) {
    zzLexicalState = newState;
  }


  /**
   * Returns the text matched by the current regular expression.
   */
  public final String yytext() {
    return new String( zzBuffer, zzStartRead, zzMarkedPos-zzStartRead );
  }


  /**
   * Returns the character at position <tt>pos</tt> from the 
   * matched text. 
   * 
   * It is equivalent to yytext().charAt(pos), but faster
   *
   * @param pos the position of the character to fetch. 
   *            A value from 0 to yylength()-1.
   *
   * @return the character at position pos
   */
  public final char yycharat(int pos) {
    return zzBuffer[zzStartRead+pos];
  }


  /**
   * Returns the length of the matched text region.
   */
  public final int yylength() {
    return zzMarkedPos-zzStartRead;
  }


  /**
   * Reports an error that occured while scanning.
   *
   * In a wellformed scanner (no or only correct usage of 
   * yypushback(int) and a match-all fallback rule) this method 
   * will only be called with things that "Can't Possibly Happen".
   * If this method is called, something is seriously wrong
   * (e.g. a JFlex bug producing a faulty scanner etc.).
   *
   * Usual syntax/scanner level error handling should be done
   * in error fallback rules.
   *
   * @param   errorCode  the code of the errormessage to display
   */
  private void zzScanError(int errorCode) {
    String message;
    try {
      message = ZZ_ERROR_MSG[errorCode];
    }
    catch (ArrayIndexOutOfBoundsException e) {
      message = ZZ_ERROR_MSG[ZZ_UNKNOWN_ERROR];
    }

    throw new Error(message);
  } 


  /**
   * Pushes the specified amount of characters back into the input stream.
   *
   * They will be read again by then next call of the scanning method
   *
   * @param number  the number of characters to be read again.
   *                This number must not be greater than yylength()!
   */
  public void yypushback(int number)  {
    if ( number > yylength() )
      zzScanError(ZZ_PUSHBACK_2BIG);

    zzMarkedPos -= number;
  }


  /**
   * Resumes scanning until the next regular expression is matched,
   * the end of input is encountered or an I/O-Error occurs.
   *
   * @return      the next token
   * @exception   java.io.IOException  if any I/O-Error occurs
   */
  public Symbol yylex() throws java.io.IOException {
    int zzInput;
    int zzAction;

    // cached fields:
    int zzCurrentPosL;
    int zzMarkedPosL;
    int zzEndReadL = zzEndRead;
    char [] zzBufferL = zzBuffer;
    char [] zzCMapL = ZZ_CMAP;

    int [] zzTransL = ZZ_TRANS;
    int [] zzRowMapL = ZZ_ROWMAP;
    int [] zzAttrL = ZZ_ATTRIBUTE;

    while (true) {
      zzMarkedPosL = zzMarkedPos;

      boolean zzR = false;
      for (zzCurrentPosL = zzStartRead; zzCurrentPosL < zzMarkedPosL;
                                                             zzCurrentPosL++) {
        switch (zzBufferL[zzCurrentPosL]) {
        case '\u000B':
        case '\u000C':
        case '\u0085':
        case '\u2028':
        case '\u2029':
          yyline++;
          yycolumn = 0;
          zzR = false;
          break;
        case '\r':
          yyline++;
          yycolumn = 0;
          zzR = true;
          break;
        case '\n':
          if (zzR)
            zzR = false;
          else {
            yyline++;
            yycolumn = 0;
          }
          break;
        default:
          zzR = false;
          yycolumn++;
        }
      }

      if (zzR) {
        // peek one character ahead if it is \n (if we have counted one line too much)
        boolean zzPeek;
        if (zzMarkedPosL < zzEndReadL)
          zzPeek = zzBufferL[zzMarkedPosL] == '\n';
        else if (zzAtEOF)
          zzPeek = false;
        else {
          boolean eof = zzRefill();
          zzEndReadL = zzEndRead;
          zzMarkedPosL = zzMarkedPos;
          zzBufferL = zzBuffer;
          if (eof) 
            zzPeek = false;
          else 
            zzPeek = zzBufferL[zzMarkedPosL] == '\n';
        }
        if (zzPeek) yyline--;
      }
      zzAction = -1;

      zzCurrentPosL = zzCurrentPos = zzStartRead = zzMarkedPosL;
  
      zzState = zzLexicalState;


      zzForAction: {
        while (true) {
    
          if (zzCurrentPosL < zzEndReadL)
            zzInput = zzBufferL[zzCurrentPosL++];
          else if (zzAtEOF) {
            zzInput = YYEOF;
            break zzForAction;
          }
          else {
            // store back cached positions
            zzCurrentPos  = zzCurrentPosL;
            zzMarkedPos   = zzMarkedPosL;
            boolean eof = zzRefill();
            // get translated positions and possibly new buffer
            zzCurrentPosL  = zzCurrentPos;
            zzMarkedPosL   = zzMarkedPos;
            zzBufferL      = zzBuffer;
            zzEndReadL     = zzEndRead;
            if (eof) {
              zzInput = YYEOF;
              break zzForAction;
            }
            else {
              zzInput = zzBufferL[zzCurrentPosL++];
            }
          }
          int zzNext = zzTransL[ zzRowMapL[zzState] + zzCMapL[zzInput] ];
          if (zzNext == -1) break zzForAction;
          zzState = zzNext;

          int zzAttributes = zzAttrL[zzState];
          if ( (zzAttributes & 1) == 1 ) {
            zzAction = zzState;
            zzMarkedPosL = zzCurrentPosL;
            if ( (zzAttributes & 8) == 8 ) break zzForAction;
          }

        }
      }

      // store back cached position
      zzMarkedPos = zzMarkedPosL;

      switch (zzAction < 0 ? zzAction : ZZ_ACTION[zzAction]) {
        case 2: 
          { /* ignore */
          }
        case 51: break;
        case 4: 
          { return symbol(Symbol.MULT); /**//*case "*"*/
          }
        case 52: break;
        case 18: 
          { return symbol(Symbol.NOT);
          }
        case 53: break;
        case 5: 
          { return symbol(Symbol.IDENTIFIER);
          }
        case 54: break;
        case 28: 
          { return symbol(Symbol.NOTEQ);
          }
        case 55: break;
        case 15: 
          { return symbol(Symbol.COMMA);
          }
        case 56: break;
        case 11: 
          { return symbol(Symbol.LPAREN); /**//*case "("*/
          }
        case 57: break;
        case 13: 
          { return symbol(Symbol.LBRACE);
          }
        case 58: break;
        case 33: 
          { return symbol(Symbol.GTEQ);
          }
        case 59: break;
        case 45: 
          { return symbol(Symbol.CLASS);
          }
        case 60: break;
        case 21: 
          { return symbol(Symbol.STRING_LITERAL);
          }
        case 61: break;
        case 25: 
          { return symbol(Symbol.MINUSEQ);
          }
        case 62: break;
        case 17: 
          { return symbol(Symbol.PERIOD);
          }
        case 63: break;
        case 12: 
          { return symbol(Symbol.RPAREN); /**//*case ")"*/
          }
        case 64: break;
        case 8: 
          { return symbol(Symbol.PLUS);
          }
        case 65: break;
        case 32: 
          { return symbol(Symbol.LSHIFT);
          }
        case 66: break;
        case 35: 
          { return symbol(Symbol.IF);
          }
        case 67: break;
        case 36: 
          { return symbol(Symbol.LSHIFTEQ);
          }
        case 68: break;
        case 22: 
          { return symbol(Symbol.DIVEQ);
          }
        case 69: break;
        case 23: 
          { return symbol(Symbol.MULTEQ);
          }
        case 70: break;
        case 43: 
          { return symbol(Symbol.VOID);
          }
        case 71: break;
        case 26: 
          { return symbol(Symbol.MODEQ);
          }
        case 72: break;
        case 16: 
          { return symbol(Symbol.EQ);
          }
        case 73: break;
        case 44: 
          { return symbol(Symbol.ELSE);
          }
        case 74: break;
        case 48: 
          { return symbol(Symbol.STATIC);
          }
        case 75: break;
        case 49: 
          { return symbol(Symbol.EXTENDS);
          }
        case 76: break;
        case 24: 
          { return symbol(Symbol.PLUSEQ);
          }
        case 77: break;
        case 7: 
          { return symbol(Symbol.SEMICOLON);
          }
        case 78: break;
        case 41: 
          { return symbol(Symbol.THIS);
          }
        case 79: break;
        case 39: 
          { return symbol(Symbol.NEW);
          }
        case 80: break;
        case 14: 
          { return symbol(Symbol.RBRACE);
          }
        case 81: break;
        case 37: 
          { return symbol(Symbol.RSHIFTEQ);
          }
        case 82: break;
        case 29: 
          { return symbol(Symbol.ANDAND);
          }
        case 83: break;
        case 31: 
          { return symbol(Symbol.LTEQ);
          }
        case 84: break;
        case 47: 
          { return symbol(Symbol.WHILE);
          }
        case 85: break;
        case 6: 
          { return symbol(Symbol.INTEGER_LITERAL);
          }
        case 86: break;
        case 34: 
          { return symbol(Symbol.RSHIFT);
          }
        case 87: break;
        case 10: 
          { return symbol(Symbol.MOD); /**//*case "%"*/
          }
        case 88: break;
        case 30: 
          { return symbol(Symbol.OROR);
          }
        case 89: break;
        case 50: 
          { return symbol(Symbol.BOOLEAN);
          }
        case 90: break;
        case 20: 
          { return symbol(Symbol.GT);
          }
        case 91: break;
        case 9: 
          { return symbol(Symbol.MINUS);
          }
        case 92: break;
        case 42: 
          { return symbol(Symbol.NULL);
          }
        case 93: break;
        case 40: 
          { return symbol(Symbol.BOOLEAN_LITERAL);
          }
        case 94: break;
        case 27: 
          { return symbol(Symbol.EQEQ);
          }
        case 95: break;
        case 46: 
          { return symbol(Symbol.PRINT);
          }
        case 96: break;
        case 38: 
          { return symbol(Symbol.INT);
          }
        case 97: break;
        case 19: 
          { return symbol(Symbol.LT);
          }
        case 98: break;
        case 3: 
          { return symbol(Symbol.DIV); /**//*case "/"*/
          }
        case 99: break;
        case 1: 
          { 
          }
        case 100: break;
        default: 
          if (zzInput == YYEOF && zzStartRead == zzCurrentPos) {
            zzAtEOF = true;
              { return symbol(Symbol.EOF);
 }
          } 
          else {
            zzScanError(ZZ_NO_MATCH);
          }
      }
    }
  }


}