Re: [boost] [log][phoenix] Questions on porting to phoenix

Subject: Re: [boost] [log][phoenix] Questions on porting to phoenix
From: Thomas Heller (thom.heller_at_[hidden])
Date: 2012-01-23 08:07:11

On Mon, Jan 23, 2012 at 1:57 PM, Andrey Semashev
<andrey.semashev_at_[hidden]> wrote:
> On Mon, Jan 23, 2012 at 2:37 PM, TONGARI <tongari95_at_[hidden]> wrote:
>>
>> I wrote the sample code that conforms these requirements, full code
>> attached.
>
> Thanks a lot, this will greatly help me to get started.
>
> So, as I understand, the env argument to the actor contains arguments
> provided for evaluation. In case of filtering expression, this is fine
> as there is only one argument - the set of attributes. But in case of
> formatter there are two arguments - the stream and the log record.
> Does Phoenix pass both arguments to the actor in this case?

Yes, the environment is a fusion tuple.
It is layouted as follows:
+------------------------------+---------+
| Arguments:                   | Actions |
| +------+------+ ... +------+ |         |
| | Arg0 | Arg1 | ... | ArgN | |         |
| +------+------+ ... +------+ |         |
+------------------------------+---------+

where Arguments can be accessed with env.args() or phoenix::context(env)
Actions are the proto external transforms which determine how the
expression will be evaluted.
I have to admit the docs are very unclear about that specifc part ...
needs some loving.