[reactive] Essential Reactive functions?

[Conal Elliott]

Hi Peter,

I don't need unamb stuff since I just spawn one new thread for each merged
> event, and I use the WaitForMultipleObjects primitive to check which of the
> two event occurrences was first.
>

By "was first", do you mean the occurrence itself or when it was detected?
The latter is easier to implement but disagrees with the semantics (see
http://conal.net/blog/posts/future-values-via-multi-threading/), which is
what eventually led me to unamb.

I don't know what it takes to create and use a FRP library with pure
semantics in a strict language (like C# and F#).

Since you're using WaitForMultipleObjects and working in strict languages,
you might find Mike Sperber's thesis helpful:
http://w210.ub.uni-tuebingen.de/dbt/volltexte/2001/266/pdf/lula-thesis.pdf.
 He doesn't get the simple pure semantics of classic FRP or Reactive,
but
he does explore some of the complex issues of dealing with FRP in a strict
setting.

I'd love to hear how your experiment goes.

    - Conal

2008/12/26 Peter Verswyvelen <bugfact at gmail.com>

> I'm building a little Reactive library in C# for fun - in the same spirit
> as Conal's one - with the intension to convert that to F#, which I'm
> learning now.
> Right now I implemented  Future, Event and Reactive, and functionality to
> merge/mappend two events.
>
> Although I'm not yet sure it fully works, using some tricks from Reactive,
> it was actually really easy to implement. I don't need unamb stuff since I
> just spawn one new thread for each merged event, and I use the
> WaitForMultipleObjects primitive to check which of the two event occurrences
> was first. The code is of course a zillion times more ugly than in Haskell,
> and since I'm not using lightweight threads, it might really be slow. I
> tried to make it as immutable as possible, so it's not really imperative :)
>
> But what is the minimal set of functions one must implement to build a
> Reactive library, in the sense that all others can be implemented using
> these?
>
> Merry Xmas!
>
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