If you *want* ambiguity, consider avoiding the precedenced rule syntax and writing it directly in BNF. Precedenced rules are intended to cover the ordinary cases. If you're doing advanced and tricky stuff, laying it out in pure BNF forces you to make it clear exactly what you meant.
I find that many systems, with their advanced features and syntaxes, go too far in the DWIMery. This is handy if their "Do What I Mean" is in fact what you meant. But if the DWIMery guesses wrong, the system just makes things more complicated. So I try to not make my advanced features *too* smart. On Thu, Sep 1, 2016 at 11:48 AM, <[email protected]> wrote: > Thanks for the pointer to prose on the rule rewriting. I can read Perl > about as well as middle English -- lots of effort and guessing, and usually > getting pretty close. :-) > > Further comments inline below. > > On Wednesday, August 31, 2016 at 10:10:01 PM UTC-6, Jeffrey Kegler wrote: > >> Just in case it was unclear, that last message was aimed at the general >> reader of this read, and was not ad hominem. >> > > No offense taken -- it sounds like great advice to me in particular! > > @Anton: Off the top of my head, 2+3+4 is ambiguous in that grammar -- the >> BNF does not implement associativity. >> > > So SLIF has an implied, default associativity? I can find one IRC comment > to this effect, but I can't find it anywhere in the docs. (There's a great > potential spot in Scanless/DSL.pod where it discusses associativity....) > > This explains why my parse was not ambiguous. What if I *want* my grammar > to be ambiguous in this case? I saw another IRC comment asking for an > adverb setting for associativity of "none". Is this possible? > > Thanks! > > - Ryan > > <snip> > > -- > You received this message because you are subscribed to the Google Groups > "marpa parser" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "marpa parser" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
