As for using '_' inside a 'nil', err, no i'm not. That was just a typo in my example, I've been using captures.
On Thu, May 7, 2009 at 2:51 AM, Eric Niebler
<eric@boostpro.com> wrote:
Lee Simpson wrote:
Damn. I've just implemented the whole algorithm using your suggested approach, and I've come across a problem.
I don't have a simple way to describe my dilemma, so a complex way will ave to do :-/
First of, I'll describe the way I have implemented your suggestion.
First off, I utilize an expression of the form ((s1 = expr) >> keep(nil[action(_,...)])) for each significant component of the expression.
<snip>
Stop right there. Are you really using nil[action(_,...)] ? In this context, xpressive will replace _ with the submatch corresponding to the subexpression to which the semantic action is attached. In this case, the action is attached to nil, which always matches 0 characters. So your action will always be passed an empty submatch. I bet that's not what you want. Did you intend nil[action(s1,...)] perhaps?