On Fri, 16 Jan 2009, Duncan Coutts wrote:
If you or anyone else has further concrete suggestions / improvements then post them here now! :-)
Spell out what associativity means and what it means for that operation to have an identity. List a few examples (stating that they're not all instances), including the * and + ones for arithmetic (use this to explain the issue with multiple monoids existing on one type, possibly use it to mention newtypes and newtype deriving as a workaround). Mention the intuition of monoids as abstract 'sequences', in which the sequence itself may be hidden after evaluation or be irrelevant because the operation commutes - the two arithmetic monoids are a good example in both cases. Bonus points for explaining the relationship between monoids and folds somewhere. -- flippa@flippac.org 'In Ankh-Morpork even the shit have a street to itself... Truly this is a land of opportunity.' - Detritus, Men at Arms