kh: improve Dawn code style

Based on PR feedback. Explicit argument types, improved NOTE style,
updated comments.

pkg/hs/urbit-king/lib/Urbit/King/CLI.hs

@@ -255,7 +255,7 @@ ethNode = strOption
      $ short 'e'
     <> long "l2-endpoint"
     <> value "https://l2.urbit.org/v1/azimuth"  --TODO
-    <> help "L2 RPC API endpoint URL"
+    <> help "Azimuth Layer 2 RPC API endpoint URL"
     <> hidden
 
 new :: Parser New

pkg/hs/urbit-king/lib/Urbit/Vere/Dawn.hs

@@ -74,10 +74,8 @@ ringToPass Ring{..} = Pass{..}
 
 -- JSONRPC Functions -----------------------------------------------------------
 
--- Network.JSONRPC appeared to not like something about the JSON that Infura
--- returned; it just hung? Also no documentation.
---
 -- Our use case here is simple enough.
+-- Network.JSONRPC appeared fragile and has no documentation.
 -- So, like with Vere, we roll our own.
 
 dawnSendHTTP :: String -> L.ByteString -> RIO e (Either Int L.ByteString)
@@ -212,7 +210,7 @@ instance FromJSON PointSponsor where
 data PointRequest = PointRequest Ship
 
 instance RequestMethod PointRequest where
-  getRequestMethod _ = "getPoint"
+  getRequestMethod PointRequest{} = "getPoint"
 
 instance ToJSON PointRequest where
   toJSON (PointRequest point) = object [ "ship" .= renderShip point ]
@@ -228,7 +226,7 @@ parseAzimuthPoint (PointRequest point) response = EthPoint{..}
   epOwn = (0, 0, 0, 0)
 
   sponsorShip = Ob.parsePatp $ psWho $ pnSponsor net
-  epNet = if (pkLife key) == 0
+  epNet = if pkLife key == 0
     then Nothing
     else case sponsorShip of
       Left _  -> Nothing
@@ -267,16 +265,16 @@ removePrefix withOhEx
  where
   (prefix, suffix) = splitAt 2 withOhEx
 
-data TurfRequest = TurfRequest ()
+data TurfRequest = TurfRequest
 
 instance RequestMethod TurfRequest where
-  getRequestMethod _ = "getDns"
+  getRequestMethod TurfRequest = "getDns"
 
 instance ToJSON TurfRequest where
-  toJSON _ = object []  --NOTE  getDns takes no parameters
+  toJSON TurfRequest = object []  -- NOTE getDns takes no parameters
 
 parseTurfResponse :: TurfRequest -> [Text] -> [Turf]
-parseTurfResponse _ = map turf
+parseTurfResponse TurfRequest = map turf
    where
     turf t = Turf $ fmap Cord $ reverse $ splitOn "." t
 
@@ -397,7 +395,7 @@ dawnVent provider feed =
       (dawnPostRequests provider parseGalaxyTableEntry (map (PointRequest . Ship . fromIntegral) [0..255]))
 
     putStrLn "boot: retrieving network domains"
-    dTurf <- (dawnPostRequests provider parseTurfResponse [TurfRequest ()])
+    dTurf <- (dawnPostRequests provider parseTurfResponse [TurfRequest])
                >>= \case
                  []  -> pure []
                  [t] -> pure (nub t)