Re: [boost] [spirit][qi] Dynamically combine Boost.Spirit.Qi rules at runtime

Subject: Re: [boost] [spirit][qi] Dynamically combine Boost.Spirit.Qi rules at runtime
From: Roland Bock (rbock_at_[hidden])
Date: 2011-05-11 14:37:30

On 05/07/2011 10:37 PM, Daniel F. wrote:
> Hi,
>
> I recently tried to combine an arbitrary number of rules as 
> alternatives in Boost.Spirit.Qi. Since rules are implemented as 
> objects it seemed feasible to me. My motivation was to make certain 
> parts of my grammar easily extensible. Unfortunately, I ran into some 
> problems, so I wrote a simple program (see attachment for the complete 
> code) demonstrating the unexpected behavior. Here's the key part:
>
>
Hi,

I did something similar last year, writing a runtime-configurable 
date/time parser from small building blocks like day-, month- and year 
parsers. I used a very small portion of it to create a tutorial section 
for Spirit, but I guess Hartmut and Joel got lost in other work, so it 
never made it anywhere.

Maybe it will be useful for you though? Please see the attachment and 
let me know :-)

In this example, parsers are combined as a sequence, but combining them 
as alternatives is equally simple, of course.

Regards,

Roland