Proposal: Add Data.Semigroup to base, as a superclass of Monoid

Andreas Abel andreas.abel at
Wed Jun 12 22:13:41 CEST 2013

On 12.06.13 11:03 AM, Nikita Volkov wrote:
> Concerning the discussion on Monoid's <>. Since we've stepped on a path
> of Prelude generalization, what about reimplementing the ++ in terms of
> Monoid? It's proven to be quite useful in the Snoyman's (of Yesod)
> classy-prelude
> <> experiment.
> Just think about it: we don't lose anything, and we get the expected
> String-like API for working with Text, ByteString and etc, and we also
> free up the <> operator.

Makes sense.

+1 for ++ instead of <>.   Both are right-associative, so there are no 
problems with that.

Andreas Abel  <><      Du bist der geliebte Mensch.

Theoretical Computer Science, University of Munich
Oettingenstr. 67, D-80538 Munich, GERMANY

andreas.abel at

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