Re: [boost] [Boost.Lambda] Some new features are suggested: return, iterating yield, & local var

Subject: Re: [boost] [Boost.Lambda] Some new features are suggested: return, iterating yield, & local var
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2012-01-05 18:47:56

On 01/05/2012 07:18 PM, Dave Abrahams wrote:
>
> on Thu Jan 05 2012, Mathias Gaunard<mathias.gaunard-AT-ens-lyon.org>  wrote:
>
>> On 01/04/2012 05:05 AM, Huang Huan wrote:
>>> Yes, Boost.Phoenix do a lot forward in unname function.
>>> Unfortunately the presented features are not found in it.
>>>
>>> 2012/1/4 Mathias Gaunard<mathias.gaunard_at_[hidden]>
>>>> return is hard to implement, since each expression is building its own
>>>> expression, so you need to forward it along the whole chain.
>>>> Exceptions could also be used, but it's not very nice.
>>
>> Sorry, I meant "since each expression is building its own function" here.
>
> In principle that shouldn't limit anything, right?  There's no reason
> that "a, b" (or any other lambda expression containing a and b) has to
> be evaluated via straightforward evaluations of a and b... I think.

It can be done, but it would require a bit of work since it would affect 
the whole evaluation system.