Am 03/24/2015 um 06:40 PM schrieb Tikhon Jelvis:
As far as time-varying code goes, you were right in your intuition that it's closely related to FRP. You have, in fact, come up with a type similar to events in classical FRP—an accomplishment on its own!
My temporal type is defined as follows data Change a = Chg { ct :: Time, -- "change time" cv :: a -- "change value" } data Temporal a = Temporal { td :: a, -- "temporal default" tc :: [Change a] -- "temporal changes" } deriving (Show) I started off with "Event" instead of "Change", but found this misleading. Two successive changes with the same value have the same effect as a single change, while for Events in the sense of "left button click" there is a difference between a click and a doubleclick. I don't know if I'll ever have to intersperse Changes from two lists. In that case two successive changes to the same value *will* make a difference, because the second change my undo the effect of an interspersed change. I am still somewhat struggeling with train schedules. I'd love to craft an example with a summer and a winter schedule, but I don't quite know what to use as a value. Intuitively it'd be something like "departure time", but of what? I am not sure if there is a missing piece, or if I just have to turn away from traditional train schedules and us "train on track 1" as the changing value.