From: mirian@... (Mirian Crzig Lennox)
Date: 2001-05-31T09:23:20+09:00
Subject: [ruby-talk:16065] Re: java based interpreter and regexes

In article <xG8VO2x+zMsWv+f0SjYHkocHGNgf@4ax.com>,
Stefan Matthias Aust <sma@3plus4.de> wrote:
>
>I wasn't really successful.  Most parsers, including javacc are LL(1)
>or LL(k) parsers.  Unfortunately, Ruby can't be expressed as LL(k)
>grammar, so these parsers aren't powerful enough to be used without
>modification.
>I think, you has to use at least an LALR(k) parser, BYACC or CUP for
>example.  Unfortunately, Ruby isn't also LALR(k), not even LR(k) or
>any context free grammar. 

I'm intrigued.  What issues in Ruby prevent it from being expressible
in either LL(k) or LR(k), for sufficiently high values of 'k'?  I
wouldn't have expected there to be that many areas of semantic
ambiguity in the grammar (but admittedly I haven't attempted to
implement it).

--Mirian