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

2009/11/13 Rafael Gustavo da Cunha Pereira Pinto :

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 Stephen