[Haskell-beginners] phantom type

[Theodore Lief Gannon]

Directly relevant blog:
https://www.benjamin.pizza/posts/2017-12-15-functor-functors.html

On Sat, Mar 31, 2018, 1:41 AM Francesco Ariis <fa-ml at ariis.it> wrote:

> On Sat, Mar 31, 2018 at 07:54:50AM +0000, PICCA Frederic-Emmanuel wrote:
> > I create a method
> >
> > myMethod :: MyData Collect -> IO ()
> >
> > but I want my method to work for MyData Collect and Mydata
> Caracterization but not Unchecked.
> >
> > So It seems to me that I can not just do
> >
> > myMethod :: MyData t -> IO ()
> >
> >
> > what is the right way to solve this problem ?
>
> Hello Frederic,
>     I am in a rush so I cant write a minimal example, but wouldn't
> a typeclass + make Collect and Cara instances of that typeclass do?
> -F
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