Constraints on definition of `length` should be strengthened

[Nathan Bouscal]

On Wed, Apr 5, 2017 at 9:18 AM, Ben Franksen <ben.franksen at online.de> wrote:

> Am 03.04.2017 um 22:48 schrieb Sven Panne:
> > Tuples *are* unbiased, the bias is just an artifact of seeing them as a
> > curried function, where the positions are "eaten" from left to right.
> > Again, this mathematically correct, but more often than not the main
> intent
> > of using a tuple-
>
> Exactly. Currying is nice and convenient but it has an inherent bias.
> This bias is based on the necessity to choose an order when writing
> things down in sequence and unavoidable as long as we write programs as
> linear text.
>
Just because we can curry something doesn't mean we have to give an
> independent (biased) interpretation to the curried entity.
>

As Vladislav showed earlier, the bias is not just the order that things are
written in. It is impossible (in Haskell as it exists) to make a Functor
instance for (,b). It's not about interpretation, it's part of how the
language works.


>
> >> We can't just ignore that and pretend they're unbiased.
> >
> > We *can* ignore that, just use Henning's Decorated for an isomorphic
> > variant.
>
> And let's not forget Either which IMO should be regarded as an unbiased
> choice. I don't have a proposal for the name, though.
>
> Cheers
> Ben
>
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