Hi Jeff It sounds like maybe you just want an application that works a bit like 'cabal'. So with cabal the first argument is taken as the 'command' and then the rest are based on that: cabal build --some other --options --which may --or --may --not have --arguments Yi has a simple template for a script which should get you started, please find it attached. So here instead of processOptions, you might want, processCommand processCommand :: [ String ] -> IO () processCommand ("build" : args) = processBuildCommand args processCommand ("play" : args) = processPlayCommand args processCommand [] = putStrLn "You must supply a command" processCommand _ = putStrLn "Sorry I don't understand your command" --Probably out put help here as well processBuildCommand :: [ String ] -> IO () processBuildCommand = similar to the processOptions except now you are sure you are in a 'build' command you *might* even have a separate set of option descreptions for each command. hth allan Jeff Wheeler wrote:
Hi,
I'm a slight Haskell newbie, but I'm trying to write a terminal-like application that accepts simple commands with optional arguments, and can then execute them. Most of these commands will need IO, as later I will want to communicate over USB for most of them.
I was hoping, though, that I could get some comments on the initial architecture I've been playing with [1].
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?
Thanks in advance, Jeff Wheeler
[1] http://media.nokrev.com/junk/cli/ _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
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