Re: new Cohttp interface progress

[Richard Mortier <Richard.Mortier@xxxxxxxxxxxxxxxx>]

On 21 Aug 2012, at 00:03, Anil Madhavapeddy wrote:

> On Tue, Aug 07, 2012 at 09:55:24PM +0100, Richard Mortier wrote:
>> 
>> 
>> hm- do you have pointers to any examination of this, or is it just well
>> known?
> 
> It's simply because they have different semantics.  There are some numbers
> in this paper from 2010 on different concurreny mechanisms in OCaml:
> http://hal.inria.fr/docs/00/49/32/13/PDF/lwc.pdf
> It doesn't cover Async as it has only be open-sourced this year, but you
> get the idea I hope...

i get that there are a number of different ways of implementing this, and of 
designing the apis to be used; but i don't yet completely understand why it's 
useful to abstract them all behind a single monad, and then allow the 
programmer to choose their own implementation.  and i certainly don't see that 
programmers are likely to be in a position to make an informed choice based on 
the performance impact of the implementation selected without going to a *lot* 
of work (possibly repeatedly).

though it does suggest, at least to me, that some sort of sensible automated 
performance simulation/monitoring framework would make sense, and would require 
a wrapping of this stuff in a monad of some kind. 

> I'm porting my avsm/ocaml-github bindings over to use the new API to make
> sure any issues are shaken out, and then I will write a Mirage Net.Channel
> version that we can use on the website.  Then, any core protocol parsing
> changes will be shared across all the various backends, and we have a nice
> reference for what Async, Lwt and Mirage-net code all looks like in one
> place.

cool :)

>> by strings do you mean bigarray thingies?  if so then i buy that - it
>> would be nice to have a single encapsulated layer that meant that all
>> the mirage protocol libraries could take a single dependency on it and
>> be usable from any other ocaml program.
> 
> Yeah. I haven't actually done this yet as I'd like to stabilise everything
> else. However, it shouldn't be too hard to define a sub-set of the String
> module and use that to directly read/write from Bigarray too.  We will
> have to port the Re regexp library first, but that should also be very
> quick.


cool....

-- 
Cheers,

R.




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