[Haskell-cafe] Comments from OCaml Hacker Brian Hurt

Don Stewart dons at galois.com
Thu Jan 15 15:51:28 EST 2009

> On Thu, 2009-01-15 at 19:46 +0000, Andrew Coppin wrote:
> > PS. As a small aside... Is the Monoid class actually used *anywhere* in 
> > all of Haskell?
> Yes.
> They're used quite a lot in Cabal. Package databases are monoids.
> Configuration files are monoids. Command line flags and sets of command
> line flags are monoids. Package build information is a monoid.
> It is also used in the Foldable class which is a nice interface for
> traversing/visiting structures. Binary serialisation is also a monoid.

Also, xmonad configuration hooks are monoidal. So all those xmonad users
gluing together keybindings are using the Monoid class.

-- Don

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