From: Clifford Heath <no@...>
Date: 2009-06-10T13:40:06+09:00
Subject: Re: treetop grammar problem

Robert Schaaf wrote:
> But the empty string passes!

It's not a general solution, but you can require that *something*
follows, using &.

rule roman_numeral
  &. ( stuff )
end

There's no better way to write M{0,3}

Clifford Heath.