Functor, Applicative, Monad, Foldable, Traversable instances for (, , ) a b

[dominic at steinitz.org]

Since "God made the integers…” perhaps the question of whether 0 is an integer is best left to theologians.

On the other hand, in set theory a tuple is defined as a set containing two elements and in category theory, a product is a limit of a discrete category with two objects. Of course you can treat a tuple as a decorated container containing one element but I doubt many mathematicians think of them this way. Before anyone points out that I shouldn’t think of types as sets, the same applies to \omega-complete partial orders.

Perhaps I had better be explicit and say please no aka -1.

> The length of ((,) a) is exactly one. Anything else is ridiculous. Try
> arguing against that, instead of a position that does not exist ("length
> of tuples"). I wrote this instance some number of years ago (about 11),
> and have used it on teams all over the place. Not once was there an
> issue that was not quickly corrected, and thereby achieving the
> practical benefits that come with, by providing a better understanding.
> That understanding is above. The length of ((,) a) is exactly one. Say
> it with me.
> 
> 
> On 01/04/17 10:08, Francesco Ariis wrote:
>> On Sat, Apr 01, 2017 at 07:59:00AM +1000, Tony Morris wrote:
>>> A contrary, consistent position would mean there is a belief in all of
>>> the following:
>>> 
>>> * the length of any value of the type ((,) a) is not 1
>>> * 0 is not an integer


Dominic Steinitz
dominic at steinitz.org
http://idontgetoutmuch.wordpress.com