[antlr-interest] Antlr 3 doesn't like '%' operator in actions?

[Wincent Colaiuta]

El 21/6/2007, a las 19:18, Bernardo Elayda escribió:

> invalid StringTemplate % shorthand syntax '%'

You're getting this error because % has special meaning for  
StringTemplate, and ANTLR uses StringTemplate under the covers.

In most cases you can escape the special character, so in your  
example you would need to change:

> prog : lhs=MYINT (MYCOMMA MYINT)*
>     {
>            Integer temp = new Integer($lhs.text);
>            int i = temp.intValue();
>            int j = i % 16;
>     }
>     ;

To:

> prog : lhs=MYINT (MYCOMMA MYINT)*
>     {
>            Integer temp = new Integer($lhs.text);
>            int i = temp.intValue();
>            int j = i \% 16;
>     }
>     ;

I think it would be nice if ANTLR shielded grammar authors from that  
particular implementation detail, but it's the way things are for now.

Be aware that there are some lexer-related cases in which even  
escaping the special characters doesn't work (see <http:// 
www.antlr.org/pipermail/antlr-interest/2007-June/021212.html>).

Cheers,
Wincent