Re: [lojban] Re: Beta Release of PEG-based Lojban parser.

[Robin Lee Powell <rlpowell@digitalkingdom.org>]

On Thu, Apr 08, 2004 at 09:51:32PM -0400, Rob Speer wrote:
> On Thu, Apr 08, 2004 at 05:28:58PM -0700, Robin Lee Powell wrote:
> > At some point the parser needs to be taught to output something more
> > useful than just the text it succeeded at parsing, but I'm really
> > hoping someone with actual Java experience will look at that.
> 
> So I assume this means you can't currently get parse trees out of it.

Correct.

> But it's not something about PEGs that you can't get parse trees,
> right?

Nope.

> With the right code, the parse trees could be output?

Absolutely.  I've been bugging the parser generator writers about this,
actually.

> The reason I ask is that this summer, I've got a research job in
> semantic interpretation of natural languages. I've gotten permission
> from my advisor to apply my research to Lojban.

Cool!

> This technique of semantic interpretation involves taking a CFG and
> assigning a lambda expression to every rule. You then apply these
> lambda expressions up a parse tree, and at the top you end up with an
> expression encoding the meaning of the sentence.

Bear in mind that PEGs != CFGs, and that Lojban (probably) cannot be
expressed in a straight CFG.  But you probably knew that.

-Robin

-- 
http://www.digitalkingdom.org/~rlpowell/  ***  I'm a *male* Robin.
"Many philosophical problems are caused by such things as the simple
inability to shut up." -- David Stove, liberally paraphrased.
http://www.lojban.org/  ***  loi pimlu na srana .i ti rocki morsi