[antlr-interest] Skipping grammar

Arnar Birgisson arnarb at oddi.is
Tue Oct 7 02:47:29 PDT 2003


I'm sorry, this obviously doesn't work. Change

if (++i > 0)

to 

if (i++ > 0)

and it should.

Arnar

> -----Original Message-----
> From: Arnar Birgisson [mailto:arnarb at oddi.is] 
> Sent: 7. október 2003 09:44
> To: antlr-interest at yahoogroups.com
> Subject: RE: [antlr-interest] Skipping grammar
> 
> 
> I haven't tried this, but you could have this in your lexer:
> 
> class MyLexer extends Lexer
> 
> tokens {
>   INNER_LCURLY, INNER_RCURLY;
> }
> 
> {
>   private int nestingLevel = 0;
> }
> 
> LCURLY
>   : '{' { if (++i > 0) $setType(INNER_LCURLY); }
>   ;
> 
> RCURLY
>   : '}' { if (i > 0) { i--; $setType(INNER_RCURLY); }
>   ;
> 
> which gives the parser seperate tokens for inner and outer 
> curly-braces.
> This allows you to do this in the Parser
> 
> method
>   : "method" mName LCURLY ( ~RCURLY )* RCURLY
>   ;
> 
> Arnar
> 
> > -----Original Message-----
> > From: pwolleba [mailto:pwolleba at yahoo.no] 
> > Sent: 7. október 2003 07:19
> > To: antlr-interest at yahoogroups.com
> > Subject: [antlr-interest] Skipping grammar
> > 
> > 
> > I am pretty new to ANTLR so maybe this question is very trivial, if 
> > so even better then maybe it is a simple solution to my problem. 
> > Anyway I am struggling with writing a new parser in ANTLR 
> to replace 
> > and old implementation in Flex/Bison, this to make a 
> product that are 
> > open for implementation from both C++ as well as Java. 
> > 
> > The parser will parse a language that we are using to build 
> > databases, and it must support this language 100% if to be 
> accepted. 
> > 
> > Here is the code cutting that I am struggling with.
> > 
> > method name{
> >   SomeText!()text[];
> >   if(a < b && b < c){
> >      SomeText()!()[];
> >   }
> >   else{
> >      SomeText()!()[];
> >   };
> > };
> > 
> > I am not interesting in the expression that is inside the name 
> > method, I just want ANTLR to grab the text for me, and put it as a 
> > node inside the tree. The problem is the fact that the if/else 
> > statement is ending with a "};" which is the same token as 
> the method 
> > end token, and I have no guarantee that there could be more 
> that one 
> > inside the method. A solution would be to make a counter that will 
> > increase for each "{" and decrease for each "}", then I would know 
> > when the method ends. To my frustration I don't know how I should 
> > make such a counter in ANTRL, that still supports implement in both 
> > Java or C++ code.
> > I would be really really happy if someone could help me with this 
> > problem!
> > 
> > Best reagards,
> > 
> > Per
> > 
> > 
> > 
> >  
> > 
> > Your use of Yahoo! Groups is subject to 
> > http://docs.yahoo.com/info/terms/ 
> > 
> > 
> 
> 
>  
> 
> Your use of Yahoo! Groups is subject to 
> http://docs.yahoo.com/info/terms/ 
> 
> 


 

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