exprscanner.java

SkipOOMiniJOOL教学语言的编译器前端

            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 4: 
          { /* ignore */
          }
        case 56: break;
        case 55: 
          { return symbol(ExprSymbol.EXTENDS);
          }
        case 57: break;
        case 31: 
          { return symbol(ExprSymbol.MODEQ);
          }
        case 58: break;
        case 51: 
          { return symbol(ExprSymbol.RETURN);
          }
        case 59: break;
        case 39: 
          { return symbol(ExprSymbol.LSHIFT);
          }
        case 60: break;
        case 38: 
          { return symbol(ExprSymbol.LTEQ);
          }
        case 61: break;
        case 27: 
          { return symbol(ExprSymbol.MULTEQ);
          }
        case 62: break;
        case 40: 
          { return symbol(ExprSymbol.INT);
          }
        case 63: break;
        case 9: 
          { return symbol(ExprSymbol.LBRACK);
          }
        case 64: break;
        case 52: 
          { return symbol(ExprSymbol.STATIC);
          }
        case 65: break;
        case 35: 
          { return symbol(ExprSymbol.OROR);
          }
        case 66: break;
        case 22: 
          { return symbol(ExprSymbol.NOT);
          }
        case 67: break;
        case 43: 
          { return symbol(ExprSymbol.LSHIFTEQ);
          }
        case 68: break;
        case 23: 
          { return symbol(ExprSymbol.GT);
          }
        case 69: break;
        case 5: 
          { return symbol(ExprSymbol.DIV);
          }
        case 70: break;
        case 11: 
          { return symbol(ExprSymbol.LPAREN);
          }
        case 71: break;
        case 29: 
          { return symbol(ExprSymbol.PLUSEQ);
          }
        case 72: break;
        case 24: 
          { return symbol(ExprSymbol.LT);
          }
        case 73: break;
        case 50: 
          { return symbol(ExprSymbol.WHILE);
          }
        case 74: break;
        case 46: 
          { return symbol(ExprSymbol.NULL);
          }
        case 75: break;
        case 32: 
          { return symbol(ExprSymbol.EQEQ);
          }
        case 76: break;
        case 14: 
          { return symbol(ExprSymbol.RBRACE);
          }
        case 77: break;
        case 20: 
          { return symbol(ExprSymbol.MOD);
          }
        case 78: break;
        case 34: 
          { return symbol(ExprSymbol.ANDAND);
          }
        case 79: break;
        case 54: 
          { return symbol(ExprSymbol.BOOLEAN);
          }
        case 80: break;
        case 42: 
          { return symbol(ExprSymbol.RSHIFTEQ);
          }
        case 81: break;
        case 19: 
          { return symbol(ExprSymbol.MINUS);
          }
        case 82: break;
        case 37: 
          { return symbol(ExprSymbol.RSHIFT);
          }
        case 83: break;
        case 36: 
          { return symbol(ExprSymbol.GTEQ);
          }
        case 84: break;
        case 53: 
          { return symbol(ExprSymbol.STRING);
          }
        case 85: break;
        case 7: 
          { return symbol(ExprSymbol.IDENTIFIER, yytext());
          }
        case 86: break;
        case 44: 
          { return symbol(ExprSymbol.BOOLEAN_LITERAL,new Boolean(yytext()));
          }
        case 87: break;
        case 10: 
          { return symbol(ExprSymbol.RBRACK);
          }
        case 88: break;
        case 33: 
          { return symbol(ExprSymbol.NOTEQ);
          }
        case 89: break;
        case 16: 
          { return symbol(ExprSymbol.COMMA);
          }
        case 90: break;
        case 15: 
          { return symbol(ExprSymbol.SEMICOLON);
          }
        case 91: break;
        case 28: 
          { return symbol(ExprSymbol.IF);
          }
        case 92: break;
        case 18: 
          { return symbol(ExprSymbol.PLUS);
          }
        case 93: break;
        case 1: 
          { string.append(yytext());
          }
        case 94: break;
        case 12: 
          { return symbol(ExprSymbol.RPAREN);
          }
        case 95: break;
        case 41: 
          { return symbol(ExprSymbol.NEW);
          }
        case 96: break;
        case 30: 
          { return symbol(ExprSymbol.MINUSEQ);
          }
        case 97: break;
        case 21: 
          { return symbol(ExprSymbol.EQ);
          }
        case 98: break;
        case 49: 
          { return symbol(ExprSymbol.CLASS);
          }
        case 99: break;
        case 48: 
          { return symbol(ExprSymbol.VOID);
          }
        case 100: break;
        case 47: 
          { return symbol(ExprSymbol.ELSE);
          }
        case 101: break;
        case 2: 
          { throw new RuntimeException("Illegal character \""+yytext()+
                                                              "\" at line "+yyline+", column "+yycolumn);
          }
        case 102: break;
        case 13: 
          { return symbol(ExprSymbol.LBRACE);
          }
        case 103: break;
        case 6: 
          { return symbol(ExprSymbol.MULT);
          }
        case 104: break;
        case 3: 
          { string.setLength(0); yybegin(StringHandle);
          }
        case 105: break;
        case 45: 
          { return symbol(ExprSymbol.THIS);
          }
        case 106: break;
        case 8: 
          { return symbol(ExprSymbol.INTEGER_LITERAL ,new Integer(yytext()));
          }
        case 107: break;
        case 17: 
          { return symbol(ExprSymbol.DOT);
          }
        case 108: break;
        case 25: 
          { yybegin(YYINITIAL); return symbol(ExprSymbol.STRING_LITERAL, string.toString());
          }
        case 109: break;
        case 26: 
          { return symbol(ExprSymbol.DIVEQ);
          }
        case 110: break;
        default: 
          if (zzInput == YYEOF && zzStartRead == zzCurrentPos) {
            zzAtEOF = true;
            zzDoEOF();
            switch (zzLexicalState) {
            case YYINITIAL: {
              return symbol(ExprSymbol.EOF);
            }
            case 119: break;
            default:
              { return new java_cup.runtime.Symbol(ExprSymbol.EOF); }
            }
          } 
          else {
            zzScanError(ZZ_NO_MATCH);
          }
      }
    }
  }

  /**
   * Converts an int token code into the name of the
   * token by reflection on the cup symbol class/interface ExprSymbol
   *
   * This code was contributed by Karl Meissner <[e-mail]>
   */
  private String getTokenName(int token) {
    try {
      java.lang.reflect.Field [] classFields = ExprSymbol.class.getFields();
      for (int i = 0; i < classFields.length; i++) {
        if (classFields[i].getInt(null) == token) {
          return classFields[i].getName();
        }
      }
    } catch (Exception e) {
      e.printStackTrace(System.err);
    }

    return "UNKNOWN TOKEN";
  }

  /**
   * Same as next_token but also prints the token to standard out
   * for debugging.
   *
   * This code was contributed by Karl Meissner <[e-mail]>
   */
  public java_cup.runtime.Symbol debug_next_token() throws java.io.IOException {
    java_cup.runtime.Symbol s = next_token();
    System.out.println( "line:" + (yyline+1) + " col:" + (yycolumn+1) + " --"+ yytext() + "--" + getTokenName(s.sym) + "--");
    return s;
  }

  /**
   * Runs the scanner on input files.
   *
   * This main method is the debugging routine for the scanner.
   * It prints debugging information about each returned token to
   * System.out until the end of file is reached, or an error occured.
   *
   * @param argv   the command line, contains the filenames to run
   *               the scanner on.
   */
  public static void main(String argv[]) {
    if (argv.length == 0) {
      System.out.println("Usage : java ExprScanner <inputfile>");
    }
    else {
      for (int i = 0; i < argv.length; i++) {
        ExprScanner scanner = null;
        try {
          scanner = new ExprScanner( new java.io.FileReader(argv[i]) );
          while ( !scanner.zzAtEOF ) scanner.debug_next_token();
        }
        catch (java.io.FileNotFoundException e) {
          System.out.println("File not found : \""+argv[i]+"\"");
        }
        catch (java.io.IOException e) {
          System.out.println("IO error scanning file \""+argv[i]+"\"");
          System.out.println(e);
        }
        catch (Exception e) {
          System.out.println("Unexpected exception:");
          e.printStackTrace();
        }
      }
    }
  }


}