Proposal: Add cons function to Data.List module

[Tony Morris]

If we're looking at things like this, have you seen the At, Cons and
Empty type-classes in lens?

On 13/9/19 1:13 am, David Feuer wrote:
> I think Michael Snoyman did a good job of starting that conversation
> with his IsSequence class in mono-traversable. I don't agree with a
> lot of the specific design decisions he's made, but I think we should
> definitely think about previous experience in that space.
>
> Personally, I prefer an MPTC-based interface for the monomorphic
> stuff. This is mostly a matter of taste, of course. One important
> idea, of course, is that of a free monoid:
>
> type family Elem xs
>
> class e ~ Elem c => MonoFoldable e c where
>   mfoldMap :: Monoid m => (e -> m) -> c -> m
>
> class (MonoFoldable e c, Monoid c) => MonoSequence e c where
>   mSingleton :: e -> c
>   -- All other methods can be optional
>
> class (forall e. Monoid (t e)) => Monoid1 t
> instance (forall e. Monoid (t e)) => Monoid1 t
>
> class (Traversable t, Monoid1 t) => Sequence t where
>   singleton :: e -> t e
>   -- All other methods can be optional
>
> On Thu, Sep 12, 2019, 10:42 AM Andreas Abel <andreas.abel at ifi.lmu.de
> <mailto:andreas.abel at ifi.lmu.de>> wrote:
>
>     I think this proposal was be stronger if it would lay out the bigger
>     picture, i.e., directions towards a unified interface to
>     sequence-like
>     collections.
>
>     -1 in its current form.
>
>     On 2019-09-11 16:32, Helmut Schmidt wrote:
>     > Taylor,
>     >
>     > Is it really necessary for you to be so rude? I can assure you
>     that my
>     > proposal has been made in the same good faith as your proposal
>     which
>     > inspired mine.
>     >
>     > Besides that unnecessary snark you do make an excellent point
>     regarding
>     > the poor discoverability of the list constructor which I imagine
>     must
>     > cause a lot of confusion among newcomers.Thank you for keeping
>     an open mind!
>     >
>     >
>     >
>     > Am Mi., 11. Sept. 2019 um 11:21 Uhr schrieb Taylor Fausak
>     > <taylor at fausak.me <mailto:taylor at fausak.me>
>     <mailto:taylor at fausak.me <mailto:taylor at fausak.me>>>:
>     >
>     >     I suspect this proposal was not made in good faith. I feel
>     like it
>     >     was meant to make fun of my list singleton proposal.
>     >
>     >     In spite of that, I am in favor of this proposal. One of the
>     (very
>     >     minor!) problems with lists in Haskell is that they can’t be
>     >     documented with Haddock because they’re part of the syntax. For
>     >     example, if you search Hoogle for `(:)` or `a -> [a] -> [a]` you
>     >     won’t find the venerable list constructor. You will find
>     `cons` from
>     >     the `extra` package, which I think suggests that this
>     proposal is a
>     >     good idea.
>     >
>     >     +1
>     >
>     >      > On Sep 11, 2019, at 4:13 AM, Oliver Charles
>     >     <ollie at ocharles.org.uk <mailto:ollie at ocharles.org.uk>
>     <mailto:ollie at ocharles.org.uk <mailto:ollie at ocharles.org.uk>>> wrote:
>     >      >
>     >      > On Wed, Sep 11, 2019 at 7:36 AM Helmut Schmidt
>     >      > <helmut.schmidt.4711 at gmail.com
>     <mailto:helmut.schmidt.4711 at gmail.com>
>     >     <mailto:helmut.schmidt.4711 at gmail.com
>     <mailto:helmut.schmidt.4711 at gmail.com>>> wrote:
>     >      >
>     >      >> I can't be the only that wants this function, right?
>     >      >
>     >      > You're not the only one! I would also like this function.
>     In fact,
>     >      > only yesterday I found myself writing
>     >      >
>     >      >  ( x : ) <$> recurse xs
>     >      >
>     >      > I would have preferred
>     >      >
>     >      >  cons x <$> recurse xs
>     >      >
>     >      > +1 to adding  cons :: x -> [x] -> [x]  to  Data.List.
>     >      >
>     >      > Ollie
>     >      > _______________________________________________
>     >      > Libraries mailing list
>     >      > Libraries at haskell.org <mailto:Libraries at haskell.org>
>     <mailto:Libraries at haskell.org <mailto:Libraries at haskell.org>>
>     >      > http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries
>     >
>     >
>     > _______________________________________________
>     > Libraries mailing list
>     > Libraries at haskell.org <mailto:Libraries at haskell.org>
>     > http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries
>     >
>     _______________________________________________
>     Libraries mailing list
>     Libraries at haskell.org <mailto:Libraries at haskell.org>
>     http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries
>
>
> _______________________________________________
> Libraries mailing list
> Libraries at haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/libraries/attachments/20190916/e0619dd6/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: OpenPGP digital signature
URL: <http://mail.haskell.org/pipermail/libraries/attachments/20190916/e0619dd6/attachment.sig>