On 2013-08-08 at 13:22:41 +0200, David Luposchainsky wrote:
On 2013-08-08 13:09, Henning Thielemann wrote:
For me using the arrow functions as Data.Tuple and Data.Either utility functions is abuse. Control.Arrow is meant to generalize (->). If you call maybeLeft and MaybeRight this is certainly not your intention.
That is precisely my point. The functionality is there, it's accessible, but due to meta-concerns (i.e. the "meaning of using these functions") they should not be used in a certain context. The syntax is sort of nice though, so maybe we should adopt that for Either/Tuple where applicable.
Btw, I have been wondering ever since I read[1] why Data.Tuple and Data.Either doesn't provide all those useful combinators mentioned in that paper for product and sum types. [1] "Functional Programming with Bananas, Lenses, Envelopes and Barbed Wire" http://citeseer.ist.psu.edu/viewdoc/summary?doi=10.1.1.41.125