On Wed, Oct 8, 2008 at 12:20 AM, Don Stewart
Several very elegant FRP approaches are emerging, most visibly FRP.Reactive, which rely on blocking on multiple variables at once, continuing when the *first* of them is available. . . inside an unsafePerformIO, so the beautiful STM "orElse" solution is not available. The current solution is to race threads against each other, and have
one that finishes first kill the other one. This is implemented, for example, in Data.Unamb. However, our empirical tests have shown that
lrpalmer: the the
GHC scheduler is not *quite* good enough to handle this efficiently, and ends up introducing too much latency and nondeterminacy.
Cool! Does you IVar implementation have anything in common with previous proposals for things called IVar (or say, 'ports', http://www.cse.unsw.edu.au/~chak/haskell/ports/http://www.cse.unsw.edu.au/%7Echak/haskell/ports/ )?
Yes, I picked up the name from haskell-cafe discussions a while back. Various forms have been popping in and out of the reactive libraries. I hadn't seen ports before. What's the background for this abstraction?
So like I said, I'm not too sure, I just stole the name and vague idea from discussions about it. As is easily noticed from the jive above, it's motivated by the continuous barrage of suboptimal FRP libraries. While I'm working on reactive from the top down, this is the beginning of one I have planned, taking baby steps from the bottom up (and it'll likely get incorporated into reactive too). Luke