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

John Meacham john at repetae.net
Tue Jun 30 18:39:39 EDT 2009

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 Meacham - ⑆repetae.net⑆john⑈ - http://notanumber.net/

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