Re: Advice needed, please

[Hans Aberg]

On 6 Jun 2009, at 23:29, xelanoimis wrote:

> I'm updating my scripting language and I need some help from someone  
> more
> experienced with bison who would like to have a look at my grammar.  
> As it is
> now it works fine, but I just want to make sure I didn't do any bad  
> things
> in there. Or if there's a way to "optimize" it, make the result  
> smaller,
> faster, etc...

You might inquiry the Usenet newsgroup comp.compilers.

> I have some "shift/reduce conflicts" and I wonder if I must fix them  
> or just
> use the %expect option to silence the warning.

Opinions differ, but not fixing could indicate grammar errors. Look  
into the .output file for the parsing "." in the conflicting rules,  
and set token precedences on the tokens immediately before and after.

> Also I wonder about reporting the parser error. I get the line  
> number but it
> doesn't always say a suggestive message, like missing ';' or missing  
> '}'.
> For example when I have an error in the top level it says: "parse  
> error,
> expecting '$". I'm not sure where this came from and how can I get a  
> better
> message.

These are default messages that Bison generates. Better ones are on  
the todo list.

  Hans