[Haskell-cafe] Could someone teach me why we use Data.Monoid?

David Place d at vidplace.com
Fri Nov 13 12:48:13 EST 2009

Magicloud Magiclouds <magicloud.magiclouds at gmail.com> wrote:

> Message: 26
> Date: Sat, 14 Nov 2009 01:11:27 +0800
> From: Magicloud Magiclouds <magicloud.magiclouds at gmail.com>
> Subject: Re: [Haskell-cafe] Could someone teach me why we use
> 	Data.Monoid?
> To: Stephen Tetley <stephen.tetley at gmail.com>
> Cc: haskell-cafe <haskell-cafe at haskell.org>
> Message-ID:
> 	<3bd412d40911130911v4f3ac0b9laebca79f5921491d at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
> That is OK. Since understand the basic concept of monoid (I mean the
> thing in actual math), the idea here is totally not hard for me. But
> the sample here does not show why (or how) we use it in programming,
> right?

For an example of it's use, you might enjoy reading my article in the Monad.Reader  "How to Refold a Map."

> http://www.haskell.org/sitewiki/images/6/6a/TMR-Issue11.pdf


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