An IsString (NonEmpty Char) instance

[Merijn Verstraaten]

> On 4 Sep 2017, at 0:25, Ivan Lazar Miljenovic <ivan.miljenovic at gmail.com> wrote:
> 
> Sorry, yes, I was thinking that GHC could determine that the result
> was Nothing and throw a type-checking failure, but that doesn't work.

So, I proposed something like this a year or more ago and got shot down because people wanted a proof-of-concept to prove it usefulness first. I implemented a very rough one that I've been thinking about polishing to the point of actually being useful (Especially now that we can *finally* derive Lift instance for other datatypes). Comments/feedback welcome, but I'm not sure how soon I can get back to this.

https://hackage.haskell.org/package/validated-literals

Cheers,
Merijn