JLex

Question for JLex (lexer).


How do I use - in other words - what do I have for
<YYINITIAL>?


My code (it alfa version!):
-------------


import java.lang.System;
import java_cup.runtime.*;
import Common.*;


class Utility
{
    public static void assert(boolean expr)
    {
      if (false == expr)
      {
          throw (new Error("Error: Assertion failed."));
      }
    }


    private static final String errorMsg[] =
    {
        "Error: Unmatched end-of-comment punctuation.",
        "Error: Unmatched start-of-comment punctuation.",
        "Error: Unclosed string.",
        "Error: Illegal character."
    };


    public static final int E_ENDCOMMENT = 0;
    public static final int E_STARTCOMMENT = 1;
    public static final int E_UNCLOSEDSTR = 2;
    public static final int E_UNMATCHED = 3;


    public static void error(int code)
    {
      System.out.println(errorMsg[code]);
    }
}


class Yytoken
{
    Yytoken(int index,String text,int line,int charBegin,int charEnd)
    {
      m_index = index;
      m_text = new String(text);
      m_line = line;
      m_charBegin = charBegin;
      m_charEnd = charEnd;
    }


    public int m_index;
    public String m_text;
    public int m_line;
    public int m_charBegin;
    public int m_charEnd;
}


%%


%{
    private int comment_count = 0;
    public String sourceFilename;
%}


%line
%char
%state COMMENT
%notunix
%cup


/* literal keyword tokens */
PROGRAM { return(new
Yytoken(Common.PROGRAM,yytext(),yyline,yychar,yychar+1)); };
PROCEDURE { return(new
Yytoken(Common.PROCEDURE,yytext(),yyline,yychar,yychar+1)); }
CONST { return(new
Yytoken(Common.CONST,yytext(),yyline,yychar,yychar+1)); }
VAR { return(new Yytoken(Common.VAR,yytext(),yyline,yychar,yychar+1)); }


IF { return(new Yytoken(Common.IF,yytext(),yyline,yychar,yychar+1)); }
CALL { return(new Yytoken(Common.CALL,yytext(),yyline,yychar,yychar+1));
}
THEN { return(new Yytoken(Common.THEN,yytext(),yyline,yychar,yychar+1));
}
BEGIN { return(new
Yytoken(Common.BEGIN,yytext(),yyline,yychar,yychar+1)); }
END { return(new Yytoken(Common.END,yytext(),yyline,yychar,yychar+1)); }


WHILE { return(new
Yytoken(Common.WHILE,yytext(),yyline,yychar,yychar+1)); }
DO { return(new Yytoken(Common.DO,yytext(),yyline,yychar,yychar+1)); }
ODD { return(new Yytoken(Common.ODD,yytext(),yyline,yychar,yychar+1)); }


NOT { return(new Yytoken(Common.NOT,yytext(),yyline,yychar,yychar+1)); }


/* punctuation */
"=" |
"#" |
"<" |
">" { return(new
Yytoken(Common.COMPARISON,yytext(),yyline,yychar,yychar+1)); }


/* names */
[A-Za-z][A-Za-z0-9_]* { return(new
Yytoken(Common.NAME,yytext(),yyline,yychar,yychar+1)); }


/* number */
[0-9]+ { return(new
Yytoken(Common.NUMBER,yytext(),yyline,yychar,yychar+1)); }


\n yyline++;


[ \n\r]+; /*white space */


/* anything else */
. { return(new Yytoken(Common.ERROR,yytext(),yyline,yychar,yychar+1)); }


%%


<YYINITIAL> { System.out.print("test"); }


--- what now? ---

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