Re: [boost] Stacking iterators vs. dataflow

Subject: Re: [boost] Stacking iterators vs. dataflow
From: Phil Endecott (spam_from_boost_dev_at_[hidden])
Date: 2008-09-03 14:13:33

Stjepan Rajko wrote:
> The direction indicated by >>= aligns with the direction of the signal
> (function call), but the data can flow in either way (either sent
> forward in the function call argument, or sent back through through
> the return value).  So, you could do
>
> rng >>= funcA >>= funcB
>
>  or
>
> funcB >>= funcA >>= rng
>
> depending on how the func and rng components are implemented.

That seems a bit odd; this is a DATA-flow library, so I would expect 
the direction of the symbol to describe the direction of the data 
flow.  And isn't the data passing method a detail of the implementation 
(in this case Signals) that your Generic layer should be hiding?

But I'm not sure I understand you; here rng is a data source and 
(surely) it supplies values via its return value; how can it be 
implemented to supply values via a parameter?

> As far as the dataflow library goes, some sort of a "automatic task
> division" library would indeed be great in conjunction with dataflow,
> but I see this as orthogonal to dataflow.

It doesn't have to be _automatic_ (i.e. runtime) task division; just 
some way of running some components in their own threads.  The 
thread-safe-signals work that you linked to before may be sufficient 
for this, though I don't know enough about Boost.Signals to fully 
understand it.

Phil.