Below, I have collected several examples of "uncanny" Haskell. These are things that may be surprising to those who have learned the language merely by doing.
Initially, I had written
hackage-fetch to see if there was
any use of
coelgot
anywhere on Hackage. At the time, there was not, but this has changed due
to my gmpint package. As of
writing, it is not surprisingly the only use of co-(Elgot algebra)s on the entirety of Hackage.
Inspired by a tweet, I decided to write an Old English name generator in Madlang. This would help my indecision (picking a favorite color is hard!), and it would unearth some limitations of Madlang.
You may have seen my post on co-(Elgot algebras),
in which I mentioned I had been using some exotic recursion schemes for my
gmpint package. I came across a similar example, this time for Mendler-style
recursion schemes. To my knowledge, it is the only published example of
a Mendler-style catamorphism.
I've been looking for an example of co-(Elgot algebra)s for quite some time, and
I came across a surprisingly nice example while working on my
gmpint package.