Haskell Foldable Wats

[Kosyrev Serge]

Mark Roberts <markandrusroberts at gmail.com> writes:
> Perhaps such warnings could be added to a tool like HLint? I do not
> think they belong in GHC.

People have circulated somewhat convincing examples that show how these
Functor instances lead to real bugs.

I doubt they would agree.

Besides -- these warning are supposed to be opt-in at the use sites,
aren't they?

-- 
с уважениeм / respectfully,
Косырев Сергей