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

Ross Paterson ross at soi.city.ac.uk
Tue Jun 30 18:56:36 EDT 2009

On Tue, Jun 30, 2009 at 03:39:39PM -0700, John Meacham wrote:
> (+>) seems to imply to me that the operator is non-associative.

It does seem to imply some asymmetry between the arguments.

> Something like (<>) or (<+>) would be better.

(<+>) is used in Control.Arrow.

(<>) is used in Data.Sequence, but as the mappend for Seq a; it could
be stolen and generalized.  (So could empty, for that matter.)

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