15 Jan
2020
15 Jan
'20
7:55 a.m.
On Tue, 14 Jan 2020, chessai . wrote:
David put my thoughts pretty clearly: is it more useful or more confusing? I am also leaning toward more confusing. Hopefully more can weigh in on this.
I also think NFData instances for reference types are more dangerous than helpful. Since laziness and strictness account for subtle programming mistakes, it is better if GHC tells you that 'rnf tvar' does possibly not perform what you expect. I'd even consider to add an instance with a type error message to show the user that this instance has been omitted by intention.