Re: [Haskell-cafe] monads with take-out options

2008/11/24 Greg Meredith

Haskellians, Some monads come with take-out options, e.g.

- List - Set

In the sense that if unit : A -> List A is given by unit a = [a], then taking the head of a list can be used to retrieve values from inside the monad.

Some monads do not come with take-out options, IO being a notorious example.

I think the take-out option for IO is usually called 'main'. :) Jason