[Haskell-beginners] FRP

Heinrich Apfelmus apfelmus at quantentunnel.de
Sun Sep 16 18:24:41 CEST 2012

Christopher Howard wrote:
> On 09/15/2012 11:16 PM, Ertugrul Söylemez wrote:
>> Summary:  FRP is about handling time-varying values like they were
>> regular values.
> Ouch!... Ouch!... My head is beginning to explode!
> So, I think I understand the main idea you just explained, but now I am
> curious about how this black magic is possible. Presumably, these
> mystical "time-varying values" would actually have to be some kind of
> partially applied function that receives a time parameter. But how do
> we, as in your example, add a literal number to a function?

As Ertugrul indicated, you first turn the literal number into a function 
(namely the constant function) and then perform arithmetic with that 

I have a few slides that may useful in understanding the "time-varying 
values as ordinary values" point better


Of course, keep in mind that at the end of the day, the  Behavior  and 
Event  types are going to be opaque. This is because the literal 
Behavior a = Time -> a  implementation would be very inefficient.

Best regards,
Heinrich Apfelmus


More information about the Beginners mailing list