But we don't want to imply it's commutative either. Having something
"bidirectional" like <> or <+> feels more commutative than associative
to me.
On Tue, Jun 30, 2009 at 6:39 PM, John Meacham
On Tue, Jun 30, 2009 at 02:54:38PM -0400, Brent Yorgey wrote:
On Tue, Jun 30, 2009 at 09:45:45AM -0700, Bryan O'Sullivan wrote:
I've thought for a while that it would be very nice indeed if the Monoid class had a more concise operator for infix appending than "a `mappend` b". I wonder if other people are of a similar opinion, and if so, whether this is worth submitting a libraries@ proposal over.
+1.
IIRC Jules Bean has proposed using (+>) for this purpose, which I like. It has the advantages of (a) not clashing with any other (common) operators, (b) making more obvious the fact that mappend is not necessarily commutative, and (c) providing the obvious (<+) for 'flip mappend' which is sometimes useful.
(+>) seems to imply to me that the operator is non-associative. Something like (<>) or (<+>) would be better.
John
-- John Meacham - ⑆repetae.net⑆john⑈ - http://notanumber.net/ _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe