[antlr-interest] A question about extracting comments

Bogdan Mitu bogdan_mt at yahoo.com
Fri Oct 11 08:43:39 PDT 2002


Hi,

If you use k=4, you will probably get rid of the nondeterminism, since "rem
" contains a space, while IDENT doesn't.

But are you sure "rem " it's what you really want? What about "rem" followed
by a tab? 

Regards,
Bogdan


--- Fan Yang <yhhf_dy at yahoo.com> wrote:
> Hi everybody,
> 
> I'm new to Antlr. I want to develop a parser for a language. In the 
> language it uses REM and ' as keywords for comment. I wrote the 
> following grammar to deal with comments. for ' kind of comments is 
> ok. But it is obviously that "rem " is nondeterminism upon IDENT. But 
> I don't know how to remove it. Would you please help me erase the 
> nondeterminism error. 
> 
> thanks a lot.
> 
> COMMENT
> : "rem "
> | '\'' (~('\n'|'\r'))* ('\n'|'\r'('\n')?)
> {$setType(ANTLR_USE_NAMESPACE(antlr)Token::SKIP); newline();}
> ; 
> 
> IDENT
> options {testLiterals=true;}
> :('a'..'z'|'_') ('a'..'z'|'_'|'0'..'9')* 
> ;
> 
> WS_ 
> :(' '
> | '\t'
> ){ _ttype = ANTLR_USE_NAMESPACE(antlr)Token.SKIP; }
> ;
> 
> 
> 
>  
> 
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ 
> 
> 
> 


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