additional documentation

1 files changed, 6 insertions, 1 deletions

diff --git a/server/src/Thermoprint/Server/API.hs b/server/src/Thermoprint/Server/API.hs
index 9559ad1..e147ac3 100644
--- a/server/src/Thermoprint/Server/API.hs
+++ b/server/src/Thermoprint/Server/API.hs
@@ -36,12 +36,16 @@ import Database.Persist.Sql
 type ProtoHandler = ReaderT HandlerInput (LoggingT IO)
 type Handler      = EitherT ServantErr ProtoHandler
 
-data HandlerInput = HandlerInput { sqlPool :: ConnectionPool
+-- ^ Runtime configuration of our handlers
+data HandlerInput = HandlerInput { sqlPool :: ConnectionPool -- ^ How to interact with 'persistent' storage
                                  }
 
 handlerNat :: ( MonadReader ConnectionPool m
               , MonadLoggerIO m
               ) => m (Handler :~> EitherT ServantErr IO)
+-- ^ Servant requires its handlers to be 'EitherT ServantErr IO'
+--
+-- This generates a 'Nat'ural transformation for squashing the monad-transformer-stack we use in our handlers to the monad 'servant-server' wants
 handlerNat = do
   sqlPool <- ask
   logFunc <- askLoggerIO
@@ -54,6 +58,7 @@ handlerNat = do
   return $ hoistNat protoNat
 
 thermoprintServer :: ServerT ThermoprintAPI Handler
+-- ^ A 'servant-server' for 'ThermoprintAPI'
 thermoprintServer = listPrinters
                      :<|> (listJobs :<|> queueJob)
                      :<|> getJob <||> jobStatus <||> deleteJob