[Haskell-cafe] Terminal-like Application Design

[Jason Dusek]

Jeff Wheeler <jeff at nokrev.com> wrote:
> I suspect I should be using some sort of monad to represent the commands,
> but I don't fully understand monads, and am not sure how it would apply in
> this context.
>
> Should I be using a monad here, and if so, how?

  At risk of stating the obvious, you will need to us the IO
  monad...

  When you say "use a monad to represent" the commands, that is
  perhaps not necessary. You can represent the commands as data,
  for example:

    data MyLanguage = Go | Stop | Left | Right

    runMyLanguage :: MyLanguage -> IO ()

  The `runMyLanguage` function serves to transform commands
  as pure data into real IO actions.

--
_jsn