10 Jul
2011
10 Jul
'11
8:14 a.m.
On Sat, Jul 9, 2011 at 7:58 AM, Henning Thielemann
My stream processors are not Arrows, because 'first' cannot be implemented. However, 'arr' and '.' can be implemented. ... Since I have no Arrow instance I even have to write my own combinators that are counterparts to (&&&) and friends.
If you have arr, (.) and (&&&), then you have first as well: f **** g = (arr fst >>> f) &&& (arr snd >>> g) first' f = f **** arr id Am I missing something here? =) Cheers, -- Felipe.