Hiya, so I've spent the last 2 months or so learning Haskell. I've finished the UPenn course, LYAH and a little bit of RWH. I wanted to get a project going so I tried making an API client for the CampBX Bitcoin Market[1]. I started out by following along with the FPComplete Mailchimp API Tutorial[2]. I'm asking you beautiful people for any feedback on it so I can be sure that I'm on the right track here, stuff like code style/idioms, project layout, public interface, implementation, docs, ideas for new features, anything you want to tell me, etc.: https://github.com/prikhi/campbx-haskell Typical usage would be something like this[3]: main :: IO () main = do cfg <- defaultCampBXConfig _ <- runCampBX cfg $ do totalAskVolume <- calculateAskVolume <$> getDepth liftIO . putStrLn $ "Total Ask Volume: " ++ show totalAskVolume return () calculateAskVolume :: Depth -> BTCAmount calculateAskVolume depthList = sum . map askPrice . asks $ depthList where askPrice (Ask (_, q)) = q There are still some things I want to work on: * Define Asks and Bids[4] using Record Syntax. The JSON[5] for a Bid/Ask comes back as a 2 item Array but the generically derived instance[6] expects an object. I haven't completely wrapped my head around Aeson's Array parsing... * Write tests. I'm imagining they would be more "given this JSON, make sure the data structure is created correctly" instead of property-based testing. * Use something other than Doubles to represent Amounts + Prices. Is there a standard library for accurate math with decimals(I need up to 8 decimal places)? I suppose I could always just use Integers to represent Satoshis(the smallest subunit of bitcoins). Also I tried adding "default-extensions: OverloadedStrings" to the .cabal file and removing the pragmas from the source files, but the package wouldn't build :( [1] https://campbx.com/api.php [2] https://www.fpcomplete.com/school/to-infinity-and-beyond/competition-winners... [3] https://github.com/prikhi/campbx-haskell/blob/master/bin/CampBXMain.hs [4] https://github.com/prikhi/campbx-haskell/blob/master/src/Web/CampBX/Types.hs... [5] http://sleepanarchy.com/p/K1wuSm [6] https://github.com/prikhi/campbx-haskell/blob/master/src/Web/CampBX/Types.hs...