Earley recogniser - Leo transitives

[deniskyashif]

Hi, I noticed that there's an implementation of Joop Leo's optimisation for right recursion, but it is commented out.

I'm fairly new to the concept of this algorithm so I'm trying to learn. Is there a reason to omit this, or maybe there's some other way of achieving linear time for LR(k) grammars?

[erezsh]

It was commented out due to bugs in some edge cases.

[erezsh]

Maybe @night199uk has a better answer.

[night199uk]

The Leo implementation had a minor bug that that sometimes causes duplicate start symbols. I believe this is due to the fact that the original Joop Leo paper/implementation calls for an injected start symbol S' => S to root the generation of transitives. Unfortunately, I'm not in a position I can provide a fix right now; but hopefully that provides you some breadcrumbs.