Re: [boost] boost::proto documentation for transforms

From: Eric Niebler (eric_at_[hidden])
Date: 2007-04-27 11:59:42

Maurizio Vitale wrote:
> 
> The example calc3 was the one that cleared things up for me: there
> only apply is defined, but more importantly comments around the
> commented out call() method talks about the unneeded 'run-time
> counterpart for the transform'.  I think this dichotomy should be made
> more clear in the documentation.

Thanks for the feedback.

> An example where the runtime part does more than just reifying the
> compiletime side, by generating more complex code might also be usful.

I agree. I need an example where the call() function actually does 
something. I also need to show the State parameter getting used. Maybe 
I'll show how the fold_to_list<> transform works. FYI, it converts 
expressions like:

    a >> b >> c
or
    a |  b |  c

to fusion cons lists like:

   cons< a, cons< b, cons< c > > >

> I might have something that computes code for overflow handling and/or
> (more complex) quantization handling, if only I could make it work
> with proto...

You might look at the fold<> transform (I suggest you run the sources 
through the preprocessor first). And then try to wrap your head around 
the fold_to_list<> transform to see how the runtime component of the 
transform works. Once you understand that, you'll know proto's 
transforms inside and out.

-- 
Eric Niebler
Boost Consulting
www.boost-consulting.com