[antlr-interest] Why is the parser trying to match the wrong rule?

[Jonas Tampier]

Hello,
I just recently discovered ANTLR for my own use, that's why I still have 
a severe knowledge deficit regarding the grammar definition.

I want to use ANTLR to parse calendar data I recieve into a tree to 
handle it more easily.
However it seems, that my grammar does not fit the data structure, yet. 
Sadly I don't understand why.

I run into the problem, that daysOfWeek does just match the first day. 
So the parser ends with the errormessage:
line 4:8 mismatched input '2' expecting 'Exceptions'
which indicates, that it tries to match the exceptions rule instead of 
the day rule.

I'd be glad to get a hint pointing me into the right direction.

Jonas Tampier


This is the grammar:

/*------------------------------------------------------------------
 * PARSER RULES
 *------------------------------------------------------------------*/
 
 calendarData
     :    PARLEFT DIGIT PIPE 'CalendarData' PARLEFT PARRIGHT PARLEFT 
daysOfWeek view? exceptions? PARRIGHT ;

 daysOfWeek
     :    PARLEFT DIGIT PIPE 'DaysOfWeek' PARLEFT PARRIGHT PARLEFT day+ 
PARRIGHT;
 day     :    PARLEFT DIGIT PIPE DAYNUMBER PARLEFT PARRIGHT PARLEFT 
shift* PARRIGHT ;
 shift     :    PARLEFT DIGIT PIPE DIGIT PARLEFT 's' '|' TIME '|' 'f' 
'|' TIME PARRIGHT PARLEFT PARRIGHT PARRIGHT;
 
 view     :    PARLEFT DIGIT PIPE 'VIEW' PARLEFT 'ShowTotal' PIPE YESNO 
PARRIGHT PARLEFT PARRIGHT PARRIGHT;
 
 exceptions
     :    PARLEFT DIGIT PIPE 'Exceptions' PARLEFT PARRIGHT PARLEFT 
exceptionDay PARRIGHT;
 exceptionDay
     :    PARLEFT DIGIT PIPE NUMBER PARLEFT 'd' PIPE NUMBER PARRIGHT 
PARLEFT shift* PARRIGHT;


/*------------------------------------------------------------------
 * LEXER RULES
 *------------------------------------------------------------------*/
DAYNUMBER : '1'..'7';
PARLEFT :     '(';
PARRIGHT:    ')';
PIPE : '||';
DIGIT    : '0'..'9' ;

YESNO    :    'Y' | 'N';

TIME     : '0'..'2' DIGIT ':' '0'..'5' DIGIT;

NUMBER    : (DIGIT)+ ;

WHITESPACE : ( '\t' | ' ' | '\r' | '\n'| '\u000C' )+     { $channel = 
HIDDEN; } ;


And this is the data:

(0||CalendarData()(
  (0||DaysOfWeek()(
    (0||1()())
    (0||2()(
      (0||0(s|07:00|f|19:00)())))
    (0||3()(
      (0||0(s|07:00|f|19:00)())))
    (0||4()(
      (0||0(s|07:00|f|19:00)())))
    (0||5()(
      (0||0(s|07:00|f|19:00)())))
    (0||6()(
      (0||0(s|07:00|f|19:00)())))
    (0||7()())))
  (0||VIEW(ShowTotal|N)())
  (0||Exceptions()(
    (0||0(d|38345)())
    (0||1(d|38352)())))))