[Haskell-cafe] Please add a method for optimized concat to the Semigroup class

Stephen Tetley stephen.tetley at gmail.com
Tue May 3 13:39:12 CEST 2011

Does it have an obvious default implementation, bearing in mind it we
might really want a total function?

sconcat []     = error "Yikes - I wish this was total!"
sconcat [a]    = a
sconcat (a:as) = a <> sconcat as

Best wishes


On 3 May 2011 12:12, Yitzchak Gale <gale at sefer.org> wrote:
> It has the obvious default implementation,
> but allows for an optimized implementation for
> specific instances. That turns out to be something
> that comes up all the time (at least for me) in
> real life.

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