[Haskell-cafe] AMP - how do you motivate this in teaching?

[Erik Hesselink]

On 20 November 2015 at 02:30, Manuel Gómez <targen at gmail.com> wrote:
> I haven’t found a helpful example of an Applicative that is not a Monad
> that is practical for a lesson.

There's ZipList [0], which depending on the type of audience might be
doable. There's also Const [1], but that needs a Monoid constraint,
and since you said you considered ((,) e) as not having an
Applicative, which it does have with a Monoid constraint, perhaps
Const isn't suitable to you for that reason. There are more
interesting examples here [2].

Erik

[0] https://hackage.haskell.org/package/base-4.8.1.0/docs/Control-Applicative.html#t:ZipList
[1] http://hackage.haskell.org/package/base-4.8.1.0/docs/Control-Applicative.html#v:Const
[2] http://stackoverflow.com/questions/7220436/good-examples-of-not-a-functor-functor-applicative-monad