[lojban] Re: left recursion changes

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

On Sun, Jun 22, 2008 at 05:15:46PM -0500, Chris Capel wrote:
> OK, I caved and implemented a subset of left recursion. It was
> surprisingly easy. The PEG now checks to see if the first item in
> the first sequence in the first option is a reference to itself.
> If so, that production will try to match the other, non-recursing
> options first, and if it finds a match, will try to match the
> first option using the match from the other option as the value of
> the recursive item. It repeats this until it can't eat any more
> text. The changes I made to the grammar to use this feature
> follow. They're quite regular--decrement the number in the first
> item, remove asterisk, and add an option for the next production.

This would be your own PEG parser generator, then?  Sorry, I haven't
been following the thread.

You might want to look at whatever the Rats! guy did; his stuff also
automatically deals with left-recursion, but I think maybe in a
slightly more structured fashion?  He's pretty approachable, you
might want to ask him.

-Robin

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