Re: [Haskell-cafe] Non-advanced usage of Type classes

...and the other one being operational (which I find simpler). 2011/6/8 Brandon Allbery

On Tue, Jun 7, 2011 at 16:16, Arnaud Bailly wrote:

...

For example, while designing some program (a game...) I defined a type class thus:

...

class (Monad io) => CommandIO io where readCommand :: io Command writeResult :: CommandResult -> io ()

This is in fact one of the reasons to use type classes. In fact, you'll find a somewhat more general variety of it on Hackage in a couple of forms, the one I'm most familiar with being MonadPrompt.

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