Re: Misleading strictness annotations in Data.List.NonEmpty

On Fri, 8 Jan 2021, Keith wrote:

Currently:

head ~(a :| _) = a tail ~(_ :| as) = as

But head and tail are both strict. At best the '~'s have no effect.

Should I open a PR to change it to

head (a :| _) = a tail (_ :| as) = as

or maybe even more clearly

head !(a :l _) = a tail !(_ :| as) = as

?

The last one would trigger the "redundant bang pattern" warning that is going to be implemented/released: https://gitlab.haskell.org/ghc/ghc/issues/17340