[Haskell-cafe] Monoid wants a (++) equivalent

[Brent Yorgey]

On Wed, Jul 01, 2009 at 12:00:50AM -0400, ajb at spamcop.net wrote:
> G'day all.
>
> On Tue, Jun 30, 2009 at 08:02:48PM -0400, Daniel Peebles wrote:
>
>> But we don't want to imply it's commutative either. Having something
>> "bidirectional" like <> or <+> feels more commutative than associative
>> to me.
>
> Quoting John Meacham <john at repetae.net>:
>
>> Not really, think of '++', which doesn't commute but is visually
>> symmetric, or Data.Sequence.<>, or the common use of <> to mean
>> concatination in pretty printers.
>
> Other good examples are && and ||.

..wha?  But those ARE commutative.  Unless you mean with respect to
strictness?

-Brent