Re: Proposal: Make Semigroup as a superclass of Monoid

29 Apr 2015

      Cough - I meant semigroups introduces a NonEmpty list type.

On 29 April 2015 at 14:51, Stephen Tetley  wrote:
...
Empty lists are problematic if you want a mconcat like operation.
Edward Kmett's semigroups package introduces an EmptyList type to
avoid this (the downside being it introduces an EmptyList type).
If you don't want an mconcat like operation then Semigroup only has
one useful operation (<>).
On 29 April 2015 at 14:13, David Feuer  wrote:
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What's problematic about empty lists for semigroups?