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

Stephen Tetley stephen.tetley at gmail.com
Fri Nov 13 11:48:25 EST 2009

2009/11/13 Rafael Gustavo da Cunha Pereira Pinto <RafaelGCPP.Linux at gmail.com>:
> Monoid is the category of all types that have a empty value and an append
> operation.

Or more generally a neutral element and an associative operation:

The multiplication monoid (1,*)

9*1*1*1 = 9

1 is neutral but you might be hard pressed to consider it _empty_.

Best wishes


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