Thanks for your interest. Did I discourage using the Leo optimization? I don't remember doing that. I'm usually pushing folks to try it.
If you found Leo implementation straight-forward, you might try writing it up in blog form, or whatever. A lot of folks are interested in implementing it, but find it hard to understand. On Sun, Jul 12, 2015 at 6:30 PM, <[email protected]> wrote: > I've been a long time lurker ever since watching the FLOSS Weekly > interview with Andrew Rodland. > <https://twit.tv/shows/floss-weekly/episodes/321> I have always been > curious about parsing and decided to try and implement the algorithm in c#. > I'd like to thank the community for being so open with documentation and > implementation detail as it has been great in doing research in the > implementation. > > During parse tree creation, I ended up getting stuck on recreating the > parse forest for leo items. > > Posting on stackoverflow <http://cstheory.stackexchange.com/q/31182/32787>got > the attention of Jeffrey who led me to a solution with his comment on some > marpa documentation. I actually implemented the sparsely packed parse > forest using leo items directly and thought this implementation may be of > interest. Jeffrey mentioned that using leo semantics may be too > complicated, but it turned out to be fairly straightforward. I look at leo > items like chains that form the right spine of a SPPF tree. The SPPF is > implemented using Elizabeth Scott's algorithm > <http://www.sciencedirect.com/science/article/pii/S1571066108001497>. > Virtual nodes help in keeping the recognition time O(n), and during > creation top of the leo chain is passed into the virtual node. A index > pointer to the top of the chain is passed from leo item to leo item during > the optimization phase, forward pointers are maintained when returning from > the recursive leo optimization. > > I think the implementation is at a point where I'm ready to let the marpa > community see it and give some critique. Here is the github repo > <https://github.com/patrickhuber/pliant>. It still needs a lot of work, > but I'm pretty sure the SPPF with leo items is working properly. If there > are any test cases that you know are particularly challenging for the marpa > parser, I'd be interested in implementing them to make sure my > implementation is correct. > > -- > 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.
