[antlr-interest] Re: Why No Error?

[genericised]

Oh, I see well I'll try and get your method working then. Thanks for 
your help.

--- In antlr-interest at y..., Bogdan Mitu <bogdan_mt at y...> wrote:
> 
> --- genericised <trigonometric at s...> wrote:
> > well the lexer is defined like this now: ...
> 
> Of course we can continue like this for ever. But there will always 
be some
> incorrect input. If you want to be sure that all input has been 
parsed, you
> have to finish the main rule with EOF. If you don't care, you can 
leave it
> like this. 
> 
> Cheers,
> Bogdan
> 
> 
> 
> > 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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> > > > 
> > > > 
> > > > 
> > > 
> > > 
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> 
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