I just noticed this in the "lifetime of ranges vs. iterators" thread (which I've not really been following): Arno Sch?dl wrote:
rng | filtered( funcA ) | filtered( funcB ) | filtered( funcC ) | filtered( funcD ) | filtered( funcE )
I thought it worth pointing out the similarity, and also the difference, between this and the proposed dataflow notation. Here, operator| is being used like a shell pipe operator. In dataflow, operator| has a quite different meaning: it's a vertical line, distributing the output of "rng" to the inputs of the funcs in parallel. Confusing, perhaps? Anyway you could presumably write something like rng >>= funcA >>= funcB .... and I would be interested to hear how the two implementations compare. Is it true to say that stacked iterators implement a "data pull" style, while dataflow implements "data push"? I also note that Arno wants to use stacked iterators because this alternative: result = fn1( fn2( fn3( fn4( huge_document ) ) ) ); creates large intermediates and requires dynamic allocation. Again, a framework that allowed buffering of "sensible size" chunks and potentially distributed the work between threads could be a good solution. Phil.