[Haskell-cafe] Monoid wants a (++) equivalent
byorgey at seas.upenn.edu
Wed Jul 1 08:56:26 EDT 2009
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
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