[Haskell-cafe] Question: Lazy Incremental Evaluation and Haskell?

Heinrich Apfelmus apfelmus at quantentunnel.de
Sat Oct 8 12:08:13 CEST 2011

David Barbour wrote:
> Heinrich Apfelmus wrote:
>> Even then, events and behaviors are "one abstraction level too low". In my
>> opinion, you are better off with a library/approach geared directly towards
>> incremental computations.
> I believe behaviors are precisely the 'right' abstraction if the goal is to
> model variables in a computation changing over time. But I agree that, if
> the libraries aren't taking advantage of the implicit optimization
> opportunities, you are better off finding libraries that do.

I agree that behaviors are the right abstraction if you only want to 
know what result is being calculated, not how it is going to be calculated.

Unfortunately, the "how" is important for incremental computations 
because there is no single canonical way to implement efficient updates. 
It often depends on which functions are expensive, which can actually be 
decoupled, and so on. I don't know any good abstraction for specifying 
the "how"; I do know that FRP doesn't help much with that.

Best regards,
Heinrich Apfelmus


More information about the Haskell-Cafe mailing list