Another example are non-empty containers, e.g. for `NonEmpty` one cannot have
a total `fromList :: [a] -> NonEmpty a`.
Regards,
Marcin
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‐‐‐ Original Message ‐‐‐
On Sunday, September 19th, 2021 at 08:49, David Feuer
wrote:
> No, fromList is too
No, fromList is too much. Consider
data Foo a = Foo (IORef String) [a]
deriving Foldable
What IORef should fromList use?
On Sun, Sep 19, 2021, 2:44 AM Anthony Clayden
wrote:
> (Moving this discussion to glasgow-users. It's just not appropriate on the
> cafe.)
>
>
> > I am no longer a
(Moving this discussion to glasgow-users. It's just not appropriate on the
cafe.)
> I am no longer a novice, and yet would still have a hard time making any use
of the laws as written in constructing instances. Instead, I'd ignore the
laws and write a natural intuitive instance, and it would