Event -> Behaviour -> Event blocking

[lilac]

I can no longer reproduce the 'working' behaviour. That is, both of them now fail for me. I plead temporary insanity...

[lilac]

The bug is that the 'snap' function, when given an event which never occurs, tries to force the value of the event at time == MaxBound?. Fix:

(Event (Future (Max MaxBound, _))) `snap` _ = mempty

This doesn't fix the problem from which I extracted this example, however. I'll produce another testcase.

[conal]

See notes and a sort-of solution in #13

[lilac]

Possible fix

[EyalLotem]

Renamed to .patch so trac color-highlights it

[conal]

Richard: I love your idea of using unamb to make the AddBounds Ord instance lazier. Thanks!

[conal]

Richard,

There's something lovely to tease out in your skipToR definition. (t' max t'', r'') looks like join on Future, because, on times, max == mappend, and join on pairs mappend-s the auxiliary values.

Jules Bean (quicksilver) defined Event join using Future join instead of my clumsy adjustE (which also uses time max). I tweaked & prettied his definition until it came out to the following:

joinE :: Ord t => EventG t (EventG t a) -> EventG t a
joinE = inEvent (>>= g)
 where 
   g (e `Stepper` ee) = eFuture (e `mappend` joinE ee)

Note that the (>>=) here is on Future.

Sadly this lovely definition doesn't fix the join laziness problem.

Given that my snapshotWith used Event join, which is definable via Future join, and yours uses Future join in disguise, my hunch is that we're converging to the same definition.

I wonder now if your improved Ord on AddBounds will fix the laziness bug with Event join. I'll try some experiments.

Please keep on thinking deeply about Reactive. I love your insights!

[conal]

I tried Richard's lazier Ord for AddBounds (using unamb for short-circuiting with min MinBound and max MaxBound). It led to strange delays in a reactive-fieldtrip program. My mouse click isn't responded to until I move the mouse. I don't know what to make of this behavior.