Re: [Boost-users] [phoenix][lambda] lambda to phoenix translation: get sig (signature) from actor

Subject: Re: [Boost-users] [phoenix][lambda] lambda to phoenix translation: get sig (signature) from actor
From: Eric Niebler (eric_at_[hidden])
Date: 2010-05-31 11:25:17

On 5/31/2010 3:39 AM, Joel de Guzman wrote:
> On 5/31/2010 11:35 AM, Eric Niebler wrote:
>> On 5/30/2010 10:50 PM, alfC wrote:
<snip>
>>> Of course the patterns do not need to be necessarily *simple* in 
>>> the future, once we master Phoenix we can go beyond to write 
>>> transformation rules for expression, in order to do that I must 
>>> gain complete access to the internal subexpressions and 
>>> subexpression types.
>> 
>> In that case, I think your best bet is to build your own DSEL using
>> Proto. Proto will let you define placeholders and will build 
>> expressions for you. It will *also* give you the tools to access, 
>> analyze and transform subexpressions in the ways you describe. In 
>> essence, you'll need to implement your own mini-Phoenix. That's
>> the bad news.
>> 
>> The good news is: in the (near!) future, Phoenix will be built on 
>> top of Proto so that you'll be able to use Proto to access,
>> analyze and transform Phoenix expressions.
<snip>
> 
> Indeed very timely. See also: http://tinyurl.com/37mguzo "phoenix 
> domain language (to write mathematical formulas)"
> 
> (Cc'ing the author)
> 
> This is not the first time Phoenix has been used this way. Yet one of
> the reasons why I insist on a simple extension interface. I think 
> we're on the right track, Eric.

The "phoenix domain language" thread argues for a simple
extension interface, but that this thread argues for powerful expression
introspection and transformation facilities: two separate things, both
of which will be nicely addressed by our current working design. Yes,
we're on the right track. Finally.

-- 
Eric Niebler
BoostPro Computing
http://www.boostpro.com