-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 29/04/13 15:37, emacstheviking wrote:
Benjamin, I have managed to reduce it all to this for which I thank you, it feels much neater now...
doOption dev (Forward n) = do putStrLn $ "> STEP FORWARD " ++ (show n) forM_ [3..0] (\b -> stepBit dev ioPORTA b)
doOption dev (Backward n) = do putStrLn $ "> STEP BACKWARD " ++ (show n) forM_ [0..3] (\b -> stepBit dev ioPORTA b)
stepBit :: HWHandle -> Word8 -> Word8 -> IO () stepBit dev p b = setBit p b 0 >> setBit p b 1 where setBit p b s = HW.setPortBit dev p b s >> stepDelay
I think I will also try to use "forEach_" as well which means I can then compose is something that passes in [0..3] or [3..0] to the composition... I may even learn something in the process! God I love the way that Haskell makes you *want* to reduce things to their most succint form, even if it hurts along the way. Only Lisp ever (ha, still does!) made me feel like Haskell does, aka a total n00b after 28 years in the business! LMAO
Thanks list.
The next step would be to factor out that horrible repetition. Maybe something like this: doOption dev x = case x of (Backward n) -> stepper "FORWARD" (Forward n) -> stepper "BACKWARD" where stepper w = do putStrLn $ "> STEP " ++ w ++ (show n) forM_ [0 .. 3] (\b -> stepBit dev ioPORTA b) I think this should work. It's also easier to introduce more options this way. - -- Mateusz K. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQIcBAEBAgAGBQJRfomiAAoJEM1mucMq2pqXpc8P/1X+snuFWZkprraX0UAZ95e7 pvCGelnxxW2rN1iUolzM5rD6MYBKTBhEMBp+SALrdQ3xUIYk/EP1yRfKnxJITe1g CN08XqUcX47QMtmxQPvngKITT1L+voAL0DSei225ohT/lMIwetfbJuXub9iKzZ/G YwLenR3R2E6iznys/Z/93Kk9tP5fXrOEkAFurqhe+xYTQnvDTMClv9cYEAj4xB1f 6x9gfqt5MbvJSyJ4PrGkJtXmS4RGSrysR5Eccf2p9CETlbBEo3uBHpzAPmqGXDFs nfeuBoWxMb/X1w9ABim/i0pITR25S+XHG9HAlQNZ3jikY057Ict9YIr7xYkFjsPh PEwVPlbf3QOTJW3IBXMbVTjA7yPiJnjG/tgAB3b8NYQnVfgPAQ/g7bw77pfm9W6X ajbXgQ9slPADhG4vEKr7ktT8CD+DlOcm/iBYockQe3h6RoFSsRFSSoCOCM8ogPUl xWp7wlZeRnP4AGB+R5vSHd06Fzk60L7D7vJvgTLINjqvhWGNrcVhvkEsCm9MWXEM /rdqnbPBuUM3qz0MQnxWHvLeXgAIP5SzYxv2FthXlF+00/1Emqr1vk2F27mppDfZ Xy/PUDjYTSHLCgPNvHVLyE9xfyVAPyqM2TarBrn8jyvi5Bx7WDn++4POD5B39MvM TD57PLQJLg0oVrrLFnYQ =Mbcq -----END PGP SIGNATURE-----