category theory - Pithy summary for comonad. (Where a monad is a 'type for impure computation') -

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in terms of pithy summaries - this description of monads seems win - describing them 'type impure computation'.

what equivalent pithy (one-sentence) description of comonad?

"a type context-dependent computation"

alternatively, better "pithy description" monads might 'type output impurity', in case pithy description comonads 'type input impurity'.

(if interested in comonads, more introduction given in talks slides of mine: http://www.cl.cam.ac.uk/~dao29/talks/comonads-and-codo-talk-dorchard-2011.pdf)


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