Re: problems with bison-flex

[Laurence Finston]

On Fri, 10 Oct 2008, Jim Michaels wrote:

> flex is hitting end of file and yyparse always returns 1, error in input.
> The last strings in the file is always
> 0
> EOF
> 
> which is the tokens ZERO T_EOF.  they are expected in the parser.
> I even tried returning 0 in yylex when it saw "EOF".  no difference.
> what do I do?

I think this question came up recently, so perhaps have a look at the 
recent threads in the archive.   One thing you could try is to have 
`yylex' return an `END' token (or the equivalent) to `yyparse' when it 
sees `EOF'.  I seem to remember having a similar problem with my most 
recent parser, but I'm not entirely sure.  If I did, I fixed it quickly 
this way.

> 
> that covers non-C++ parsing problems I have questions with. I suppose I'll 
> have the same problems with C++.
> 
> do I always need to write a driver for a C++ parser/lexer combo?

For what it's worth, I have always used C++ in combination with Bison but 
I've never used the C++ parser feature.  I don't really see the point of 
it, though I'm sure the developers put it there for a reason.  It works 
just fine to generate a C parser with C++ code in the actions and compile 
with a C++ compiler.

Laurence Finston