[antlr-interest] Re: Why No Error?

[genericised]

well the lexer is defined like this now:

class CSVLexer extends Lexer;
options { charVocabulary='\3'..'\377'; }
RECORD  : '"'! (~(','|'\r'|'\n'))+ ;
COMMA   : ',' ;
NEWLINE : ('\r''\n')=> '\r''\n' //DOS
        | '\r'                  //MAC
        | '\n'                  //UNIX
        { newline(); }
        ;
WS      : (' '|'\t') { $setType(Token.SKIP); } ;

So data is expected to be like:

"a, "b, "blah
"hei, "fhei, "fhih,

so

a, b, c
a, , ,

would produce an error because it is
not the correct format anyway, if converted
to the correct format:

"a, "b, "c
"a, ", ",

this would also create an error because a
record must contain at least one character

"a, "b, "c
"a, " , " ,

would produce no error. Note that this is
behaving exactly as it should.

Davy Cricket




--- In antlr-interest at y..., Bogdan Mitu <bogdan_mt at y...> wrote:
> > ...
> > is there anything actually WRONG with me using:
> > 
> > class CSVParser extends Parser;
> > file   : (line)+ ;
> > line   : (record)+ (NEWLINE|EOF);
> > record : (r:RECORD) (COMMA)? ;
> > 
> > I would have thought that if EOF is actually matched
> > then this is a perfectly viable way of matching the
> > whole file. In fact, IF the EOF IS matched then I see
> > no reason NOT to use this way.
> 
> Should parse OK correct input. But I'm afraid it will also parse 
incorrect
> input without producing any error.
> 
> For instance, try an input like:
> 
> a, b, c
> a, , ,
> 
> which I think it's incorrect. I didn't test, but I expect that the 
parser
> will stop after the first line, without any warning or error. 
> 
> Let me know how it works.
> 
> Cheers,
> Bogdan
> 
> > 
> >  
> > 
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http://docs.yahoo.com/info/terms/ 
> > 
> > 
> > 
> 
> 
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