Re: [boost] Local and Phoenix idiosyncrasy

Subject: Re: [boost] Local and Phoenix idiosyncrasy
From: Jeffrey Lee Hellrung, Jr. (jeffrey.hellrung_at_[hidden])
Date: 2011-11-25 14:53:13

On Fri, Nov 25, 2011 at 11:37 AM, Thomas Heller
<thom.heller_at_[hidden]>wrote:

> On 11/25/2011 01:36 PM, Mathias Gaunard wrote:
>
>> On 11/24/2011 07:14 PM, Thomas Heller wrote:
>>
>>> Hi list,
>>>
>>> Can we please put an end to this insane idiosyncrasy going on here
>>> lately? It doesn't lead to anywhere!
>>>
>>> Ok, we get it ... people want to write local functions in the usual way.
>>>
>>> Here is what I have to propose: Why not combine Boost.Local and
>>> Boost.Phoenix and keep everybody happy?
>>> If the macros provided by Boost.Local would emit some instance of a
>>> phoenix::function.
>>>
>>
>> The macros provided by Boost.Local already generate PFOs.
>> The goal of Phoenix should be to integrate seamlessly with PFOs, which
>> are ubiquitous in C++.
>>
>> It shouldn't be required to make every type be a phoenix type to use it
>> with phoenix. That is, currently, the main problem with phoenix: you
>> need to adapt all functions before you can use them.
>>
>> I've already proposed the addition of a function named "lazy" (I think I
>> suggested it during both the v2 and v3 reviews), that would be trivial
>> to write, and that simply turns a PFO into a phoenix actor.
>> That little thing would make Phoenix much more usable.
>>
>> Instead of
>>
>> BOOST_PHOENIX_ADAPT_FUNCTION(**R, f_, f, N)
>>
>> /* ... */
>> void g()
>> {
>> /* ... */
>> my_higher_order_algorithm( f_(arg2, arg1) + arg3 )
>> }
>>
>> We could just write
>>
>> my_higher_order_algorithm( lazy(f)(arg2, arg1) + arg3 )
>>
>
> This functionality already exists. It's called bind. What is bind missing?
>

I would think lazy(f) would be polyary (I'm probably making up this word),
while bind(f, _1, _2 /*, etc.*/) would have a fixed arity.  Hence, I would
consider lazy(f) to be more flexible.

- Jeff